Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
A portion of the animal phylum Chordata comprised of the subphyla CEPHALOCHORDATA; UROCHORDATA, and HYPEROTRETI, but not including the Vertebrata (VERTEBRATES). It includes nonvertebrate animals having a NOTOCHORD during some developmental stage.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Common name for the only family (Petromyzontidae) of eellike fish in the order Petromyzontiformes. They are jawless but have a sucking mouth with horny teeth.
Common name for a family of eel-shaped jawless fishes (Myxinidae), the only family in the order MYXINIFORMES. They are not true vertebrates.
Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Animals that have no spinal column.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
Proteins obtained from various species of Xenopus. Included here are proteins from the African clawed frog (XENOPUS LAEVIS). Many of these proteins have been the subject of scientific investigations in the area of MORPHOGENESIS and development.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.
Phylum in the domain Eukarya, comprised of animals either with fully developed backbones (VERTEBRATES), or those with notochords only during some developmental stage (CHORDATA, NONVERTEBRATE).
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
The only species of a cosmopolitan ascidian.
A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.
The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.
A genus of pufferfish commonly used for research.
Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.
A genus of primitive fish in the family Petromyzontidae. The sole species is Petromyzon marinus, known as the sea lamprey. The adult form feeds parasitically on other fish species.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
Proteins obtained from species of fish (FISHES).
*Medical Definition:* 'Lizards' are not typically defined in the field of medicine, as they are a type of reptile and not a medical condition or healthcare-related concept; however, certain lizard species such as the Gila monster and beaded lizards possess venomous bites, which can lead to medical emergencies like envenomation requiring medical attention.
Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.
A small order of primarily marine fish containing 340 species. Most have a rotund or box-like shape. TETRODOTOXIN is found in their liver and ovaries.
The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.
Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The farthest or outermost projections of the body, such as the HAND and FOOT.
The posterior of the three primitive cerebral vesicles of an embryonic brain. It consists of myelencephalon, metencephalon, and isthmus rhombencephali from which develop the major BRAIN STEM components, such as MEDULLA OBLONGATA from the myelencephalon, CEREBELLUM and PONS from the metencephalon, with the expanded cavity forming the FOURTH VENTRICLE.
Proteins obtained from species of BIRDS.
The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)
Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.
The outer of the three germ layers of an embryo.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The two longitudinal ridges along the PRIMITIVE STREAK appearing near the end of GASTRULATION during development of nervous system (NEURULATION). The ridges are formed by folding of NEURAL PLATE. Between the ridges is a neural groove which deepens as the fold become elevated. When the folds meet at midline, the groove becomes a closed tube, the NEURAL TUBE.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Morphological and physiological development of EMBRYOS.
##### I apologize, but the term "turtles" is not a recognized medical term or concept. It is commonly referred to as a group of reptiles with a shell, and does not have any direct relevance to medical definition.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
The complex processes of initiating CELL DIFFERENTIATION in the embryo. The precise regulation by cell interactions leads to diversity of cell types and specific pattern of organization (EMBRYOGENESIS).
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
Wnt proteins are a large family of secreted glycoproteins that play essential roles in EMBRYONIC AND FETAL DEVELOPMENT, and tissue maintenance. They bind to FRIZZLED RECEPTORS and act as PARACRINE PROTEIN FACTORS to initiate a variety of SIGNAL TRANSDUCTION PATHWAYS. The canonical Wnt signaling pathway stabilizes the transcriptional coactivator BETA CATENIN.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
Common name for Carassius auratus, a type of carp (CARPS).
The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.
Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.
An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.
A family of transcription factors that control EMBRYONIC DEVELOPMENT within a variety of cell lineages. They are characterized by a highly conserved paired DNA-binding domain that was first identified in DROSOPHILA segmentation genes.
Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.
The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
Proteins found in any species of insect.
Membranous appendage of fish and other aquatic organisms used for locomotion or balance.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
A cartilaginous rod of mesodermal cells at the dorsal midline of all CHORDATE embryos. In lower vertebrates, notochord is the backbone of support. In the higher vertebrates, notochord is a transient structure, and segments of the vertebral column will develop around it. Notochord is also a source of midline signals that pattern surrounding tissues including the NEURAL TUBE development.
The field of biology which deals with the process of the growth and differentiation of an organism.
Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).
'Eye proteins' are structural or functional proteins, such as crystallins, opsins, and collagens, located in various parts of the eye, including the cornea, lens, retina, and aqueous humor, that contribute to maintaining transparency, refractive power, phototransduction, and overall integrity of the visual system.
The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Distinct regions of mesenchymal outgrowth at both flanks of an embryo during the SOMITE period. Limb buds, covered by ECTODERM, give rise to forelimb, hindlimb, and eventual functional limb structures. Limb bud cultures are used to study CELL DIFFERENTIATION; ORGANOGENESIS; and MORPHOGENESIS.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
Sharks of the family Squalidae, also called dogfish sharks. They comprise at least eight genera and 44 species. Their LIVER is valued for its oil and its flesh is often made into fertilizer.
Large, long-tailed reptiles, including caimans, of the order Loricata.
Formation of differentiated cells and complicated tissue organization to provide specialized functions.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The founding member of the nodal signaling ligand family of proteins. Nodal protein was originally discovered in the region of the mouse embryo primitive streak referred to as HENSEN'S NODE. It is expressed asymmetrically on the left side in chordates and plays a critical role in the genesis of left-right asymmetry during vertebrate development.
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.
A tube of ectodermal tissue in an embryo that will give rise to the CENTRAL NERVOUS SYSTEM, including the SPINAL CORD and the BRAIN. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. For malformation of the neural tube, see NEURAL TUBE DEFECTS.
Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.
A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.
A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.
Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
The class Insecta, in the phylum ARTHROPODA, whose members are characterized by division into three parts: head, thorax, and abdomen. They are the dominant group of animals on earth; several hundred thousand different kinds having been described. Three orders, HEMIPTERA; DIPTERA; and SIPHONAPTERA; are of medical interest in that they cause disease in humans and animals. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p1)
Established cell cultures that have the potential to propagate indefinitely.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
A family of VERTEBRATE homeodomain proteins that share homology with orthodenticle protein, Drosophila. They regulate GENETIC TRANSCRIPTION and play an important role in EMBRYONIC DEVELOPMENT of the BRAIN.
The systematic study of the complete DNA sequences (GENOME) of organisms.
A region, of SOMITE development period, that contains a number of paired arches, each with a mesodermal core lined by ectoderm and endoderm on the two sides. In lower aquatic vertebrates, branchial arches develop into GILLS. In higher vertebrates, the arches forms outpouchings and develop into structures of the head and neck. Separating the arches are the branchial clefts or grooves.
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
A salamander found in Mexican mountain lakes and accounting for about 30 percent of the urodeles used in research. The axolotl remains in larval form throughout its life, a phenomenon known as neoteny.
A fibroblast growth factor that preferentially activates FIBROBLAST GROWTH FACTOR RECEPTOR 4. It was initially identified as an androgen-induced growth factor and plays a role in regulating growth of human BREAST NEOPLASMS and PROSTATIC NEOPLASMS.
Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
Limbless REPTILES of the suborder Serpentes.
The functional hereditary units of INSECTS.
Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.
Common name for two distinct groups of BIRDS in the order GALLIFORMES: the New World or American quails of the family Odontophoridae and the Old World quails in the genus COTURNIX, family Phasianidae.
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
Contractile tissue that produces movement in animals.
The inner of the three germ layers of an embryo.
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.
The conversion of absorbed light energy into molecular signals.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Proteins containing a region of conserved sequence, about 200 amino acids long, which encodes a particular sequence specific DNA binding domain (the T-box domain). These proteins are transcription factors that control developmental pathways. The prototype of this family is the mouse Brachyury (or T) gene product.
The parts of the gene sequence that carry out the different functions of the GENES.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Synthetic analogs of NUCLEIC ACIDS composed of morpholine ring derivatives (MORPHOLINES) linked by phosphorodimidates. One standard DNA nucleic acid base (ADENINE; GUANINE; CYTOSINE; OR THYMINE) is bound to each morpholine ring.
In anatomical terms, "tail" is not used as a medical definition to describe any part of the human body; it is however used in veterinary medicine to refer to the distal portion of the spine in animals possessing tails.
The rigid framework of connected bones that gives form to the body, protects and supports its soft organs and tissues, and provides attachments for MUSCLES.
Paired respiratory organs of fishes and some amphibians that are analogous to lungs. They are richly supplied with blood vessels by which oxygen and carbon dioxide are exchanged directly with the environment.
The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.
A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)
Elements of limited time intervals, contributing to particular results or situations.
Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.
The most diversified of all fish orders and the largest vertebrate order. It includes many of the commonly known fish such as porgies, croakers, sunfishes, dolphin fish, mackerels, TUNA, etc.
Any method used for determining the location of and relative distances between genes on a chromosome.
The anterior of the three primitive cerebral vesicles of the embryonic brain arising from the NEURAL TUBE. It subdivides to form DIENCEPHALON and TELENCEPHALON. (Stedmans Medical Dictionary, 27th ed)
A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.
The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.
Transport proteins that carry specific substances in the blood or across cell membranes.
Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.
A genus of the Ambystomatidae family. The best known species are the axolotl AMBYSTOMA MEXICANUM and the closely related tiger salamander Ambystoma tigrinum. They may retain gills and remain aquatic without developing all of the adult characteristics. However, under proper changes in the environment they metamorphose.
A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.
The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.
Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.
The region in the dorsal ECTODERM of a chordate embryo that gives rise to the future CENTRAL NERVOUS SYSTEM. Tissue in the neural plate is called the neuroectoderm, often used as a synonym of neural plate.
Morphological and physiological development of EMBRYOS or FETUSES.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
'Poisonous fishes' are aquatic organisms belonging to the Phylum Chordata and Class Pisces, that contain toxic substances either in their tissues or secretions, which can cause harmful or lethal effects when ingested, touched, or coming into contact with their released toxins.
Cis-acting DNA sequences which can increase transcription of genes. Enhancers can usually function in either orientation and at various distances from a promoter.
Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.
In a medical context, the term "wing" is not typically used as a standalone definition; however, it can refer to various flat, wing-shaped structures in anatomy, such as the iliac wings of the pelvis or the zygomatic wings of the cheekbone.
An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
Genes that determine the fate of a cell or CELLS in a region of the embryo during EMBRYONIC DEVELOPMENT.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
The physiological renewal, repair, or replacement of tissue.
The total process by which organisms produce offspring. (Stedman, 25th ed)
Genotypic differences observed among individuals in a population.
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
Group of fish under the superorder Acanthopterygii, separate from the PERCIFORMES, which includes swamp eels, mullets, sticklebacks, seahorses, spiny eels, rainbowfishes, and KILLIFISHES. The name is derived from the six taxa which comprise the group. (From http://www.nanfa.org/articles/Elassoma/elassoma.htm, 8/4/2000)
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
A superorder in the class CEPHALOPODA, consisting of the orders Octopoda (octopus) with over 200 species and Vampyromorpha with a single species. The latter is a phylogenetic relic but holds the key to the origins of Octopoda.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
Monotremata is an order of mammals, including the platypus and echidnas, which are unique for laying eggs instead of giving birth to live young and for having a single body opening for both excretion and reproduction, known as a cloaca.

The developmental basis for allometry in insects. (1/2377)

Within all species of animals, the size of each organ bears a specific relationship to overall body size. These patterns of organ size relative to total body size are called static allometry and have enchanted biologists for centuries, yet the mechanisms generating these patterns have attracted little experimental study. We review recent and older work on holometabolous insect development that sheds light on these mechanisms. In insects, static allometry can be divided into at least two processes: (1) the autonomous specification of organ identity, perhaps including the approximate size of the organ, and (2) the determination of the final size of organs based on total body size. We present three models to explain the second process: (1) all organs autonomously absorb nutrients and grow at organ-specific rates, (2) a centralized system measures a close correlate of total body size and distributes this information to all organs, and (3) autonomous organ growth is combined with feedback between growing organs to modulate final sizes. We provide evidence supporting models 2 and 3 and also suggest that hormones are the messengers of size information. Advances in our understanding of the mechanisms of allometry will come through the integrated study of whole tissues using techniques from development, genetics, endocrinology and population biology.  (+info)

The homeobox gene Pitx2: mediator of asymmetric left-right signaling in vertebrate heart and gut looping. (2/2377)

Left-right asymmetry in vertebrates is controlled by activities emanating from the left lateral plate. How these signals get transmitted to the forming organs is not known. A candidate mediator in mouse, frog and zebrafish embryos is the homeobox gene Pitx2. It is asymmetrically expressed in the left lateral plate mesoderm, tubular heart and early gut tube. Localized Pitx2 expression continues when these organs undergo asymmetric looping morphogenesis. Ectopic expression of Xnr1 in the right lateral plate induces Pitx2 transcription in Xenopus. Misexpression of Pitx2 affects situs and morphology of organs. These experiments suggest a role for Pitx2 in promoting looping of the linear heart and gut.  (+info)

A Drosophila doublesex-related gene, terra, is involved in somitogenesis in vertebrates. (3/2377)

The Drosophila doublesex (dsx) gene encodes a transcription factor that mediates sex determination. We describe the characterization of a novel zebrafish zinc-finger gene, terra, which contains a DNA binding domain similar to that of the Drosophila dsx gene. However, unlike dsx, terra is transiently expressed in the presomitic mesoderm and newly formed somites. Expression of terra in presomitic mesoderm is restricted to cells that lack expression of MyoD. In vivo, terra expression is reduced by hedgehog but enhanced by BMP signals. Overexpression of terra induces rapid apoptosis both in vitro and in vivo, suggesting that a tight regulation of terra expression is required during embryogenesis. Terra has both human and mouse homologs and is specifically expressed in mouse somites. Taken together, our findings suggest that terra is a highly conserved protein that plays specific roles in early somitogenesis of vertebrates.  (+info)

Evidence for a correlation between the number of marginal band microtubules and the size of vertebrate erthrocytes. (4/2377)

In 23 species of vertebrates the dimensions of erythrocytes and the number of their marginal band microtubules were examined. A positive correlation was found between the size of erythrocytes and the number of microtubules. The absence of microtubules in diskoid erythrocytes of mammals-Camelidae-is discussed.  (+info)

The GTPase activating factor for transducin in rod photoreceptors is the complex between RGS9 and type 5 G protein beta subunit. (5/2377)

Proteins of the regulators of G protein signaling (RGS) family modulate the duration of intracellular signaling by stimulating the GTPase activity of G protein alpha subunits. It has been established that the ninth member of the RGS family (RGS9) participates in accelerating the GTPase activity of the photoreceptor-specific G protein, transducin. This process is essential for timely inactivation of the phototransduction cascade during the recovery from a photoresponse. Here we report that functionally active RGS9 from vertebrate photoreceptors exists as a tight complex with the long splice variant of the G protein beta subunit (Gbeta5L). RGS9 and Gbeta5L also form a complex when coexpressed in cell culture. Our data are consistent with the recent observation that several RGS proteins, including RGS9, contain G protein gamma-subunit like domain that can mediate their association with Gbeta5 (Snow, B. E., Krumins, A. M., Brothers, G. M., Lee, S. F., Wall, M. A., Chung, S., Mangion, J., Arya, S., Gilman, A. G. & Siderovski, D. P. (1998) Proc. Natl. Acad. Sci. USA 95, 13307-13312). We report an example of such a complex whose cellular localization and function are clearly defined.  (+info)

DNA replication in vertebrates requires a homolog of the Cdc7 protein kinase. (6/2377)

CDC7 is an essential gene required for DNA replication in Saccharomyces cerevisiae. Cdc7p homologs have recently been identified in vertebrates, but their role in DNA replication has not yet been addressed. Here we show that antibodies to the Xenopus laevis homolog, xCdc7, interfere with DNA replication in vivo in developing embryos and in vitro in cycling egg extracts. We also demonstrate cell cycle-dependent association of xCdc7 with the Mcm complex, which binds to replication origins and also is required for DNA synthesis. Taken together, these data indicate that the function of xCdc7 is conserved from fungi to vertebrates. xCdc7 protein accumulates after stimulation of resting oocytes with progesterone, suggesting a molecular explanation for previous observations that the development of the capacity for DNA replication requires protein synthesis late in meiosis I.  (+info)

Preservation of key biomolecules in the fossil record: current knowledge and future challenges. (7/2377)

We have developed a model based on the analyses of modern and Pleistocene eggshells and mammalian bones which can be used to understand the preservation of amino acids and other important biomolecules such as DNA in fossil specimens. The model is based on the following series of diagenetic reactions and processes involving amino acids: the hydrolysis of proteins and the subsequent loss of hydrolysis products from the fossil matrix with increasing geologic age; the racemization of amino acids which produces totally racemized amino acids in 10(5)-10(6) years in most environments on the Earth; the introduction of contaminants into the fossil that lowers the enantiomeric (D:L) ratios produced via racemization; and the condensation reactions between amino acids, as well as other compounds with primary amino groups, and sugars which yield humic acid-like polymers. This model was used to evaluate whether useful amino acid and DNA sequence information is preserved in a variety of human, amber-entombed insect and dinosaur specimens. Most skeletal remains of evolutionary interest with respect to the origin of modern humans are unlikely to preserve useful biomolecular information although those from high latitude sites may be an exception. Amber-entombed insects contain well-preserved unracemized amino acids, apparently because of the anhydrous nature of the amber matrix, and thus may contain DNA fragments which have retained meaningful genetic information. Dinosaur specimens contain mainly exogenous amino acids, although traces of endogenous amino acids may be present in some cases. Future ancient biomolecule research which takes advantage of new methologies involving, for example, humic acid cleaving reagents and microchip-based DNA-protein detection and sequencing, along with investigations of very slow biomolecule diagenetic reactions such as the racemization of isoleucine at the beta-carbon, will lead to further enhancements of our understanding of biomolecule preservation in the fossil record.  (+info)

Biochemical characterization of Wnt-frizzled interactions using a soluble, biologically active vertebrate Wnt protein. (8/2377)

Biochemical studies of Wnt signaling have been hampered by difficulties in obtaining large quantities of soluble, biologically active Wnt proteins. In this paper, we report the production in Drosophila S2 cells of biologically active Xenopus Wnt8 (XWnt8). Epitope- or alkaline phosphatase-tagged XWnt8 proteins are secreted by concentrated S2 cells in a form that is suitable for quantitative biochemical experiments with yields of 5 and 0.5 mg per liter, respectively. Conditions also are described for the production in 293 cells of an IgG fusion of the cysteine-rich domain (CRD) of mouse Frizzled 8 with a yield of 20 mg/liter. We demonstrate the use of these proteins for studying the interactions between soluble XWnt8 and various Frizzled proteins, membrane anchored or secreted CRDs, and a set of insertion mutants in the CRD of Drosophila Frizzled 2. In a solid phase binding assay, the affinity of the XWnt8-alkaline phosphatase fusion for the purified mouse Frizzled 8-CRD-IgG fusion is approximately 9 nM.  (+info)

A group of chordate animals (Phylum Chordata) that have a vertebral column, or backbone, made up of individual vertebrae. This group includes mammals, birds, reptiles, amphibians, and fish. Vertebrates are characterized by the presence of a notochord, which is a flexible, rod-like structure that runs along the length of the body during development; a dorsal hollow nerve cord; and pharyngeal gill slits at some stage in their development. The vertebral column provides support and protection for the spinal cord and allows for the development of complex movements and behaviors.

A zebrafish is a freshwater fish species belonging to the family Cyprinidae and the genus Danio. Its name is derived from its distinctive striped pattern that resembles a zebra's. Zebrafish are often used as model organisms in scientific research, particularly in developmental biology, genetics, and toxicology studies. They have a high fecundity rate, transparent embryos, and a rapid development process, making them an ideal choice for researchers. However, it is important to note that providing a medical definition for zebrafish may not be entirely accurate or relevant since they are primarily used in biological research rather than clinical medicine.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

Molecular evolution is the process of change in the DNA sequence or protein structure over time, driven by mechanisms such as mutation, genetic drift, gene flow, and natural selection. It refers to the evolutionary study of changes in DNA, RNA, and proteins, and how these changes accumulate and lead to new species and diversity of life. Molecular evolution can be used to understand the history and relationships among different organisms, as well as the functional consequences of genetic changes.

Chordata is a phylum in the animal kingdom that includes animals with a notochord, dorsal hollow nerve cord, pharyngeal gill slits, and a post-anal tail at some point during their development. Nonvertebrate Chordates include two classes: Tunicata (sea squirts and salps) and Cephalochordata (lancelets). These animals do not have a backbone or vertebral column, which is why they are considered nonvertebrate. Despite the lack of a vertebral column, these animals share other common characteristics with Vertebrates, such as a circulatory system and a complex nervous system.

Zebrafish proteins refer to the diverse range of protein molecules that are produced by the organism Danio rerio, commonly known as the zebrafish. These proteins play crucial roles in various biological processes such as growth, development, reproduction, and response to environmental stimuli. They are involved in cellular functions like enzymatic reactions, signal transduction, structural support, and regulation of gene expression.

Zebrafish is a popular model organism in biomedical research due to its genetic similarity with humans, rapid development, and transparent embryos that allow for easy observation of biological processes. As a result, the study of zebrafish proteins has contributed significantly to our understanding of protein function, structure, and interaction in both zebrafish and human systems.

Some examples of zebrafish proteins include:

* Transcription factors that regulate gene expression during development
* Enzymes involved in metabolic pathways
* Structural proteins that provide support to cells and tissues
* Receptors and signaling molecules that mediate communication between cells
* Heat shock proteins that assist in protein folding and protect against stress

The analysis of zebrafish proteins can be performed using various techniques, including biochemical assays, mass spectrometry, protein crystallography, and computational modeling. These methods help researchers to identify, characterize, and understand the functions of individual proteins and their interactions within complex networks.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

A nonmammalian embryo refers to the developing organism in animals other than mammals, from the fertilized egg (zygote) stage until hatching or birth. In nonmammalian species, the developmental stages and terminology differ from those used in mammals. The term "embryo" is generally applied to the developing organism up until a specific stage of development that is characterized by the formation of major organs and structures. After this point, the developing organism is referred to as a "larva," "juvenile," or other species-specific terminology.

The study of nonmammalian embryos has played an important role in our understanding of developmental biology and evolutionary developmental biology (evo-devo). By comparing the developmental processes across different animal groups, researchers can gain insights into the evolutionary origins and diversification of body plans and structures. Additionally, nonmammalian embryos are often used as model systems for studying basic biological processes, such as cell division, gene regulation, and pattern formation.

I believe there may be a misunderstanding in your question. The term "fishes" is not typically used in a medical context. "Fish" or "fishes" refers to any aquatic organism belonging to the taxonomic class Actinopterygii (bony fish), Chondrichthyes (sharks and rays), or Agnatha (jawless fish).

However, if you are referring to a condition related to fish or consuming fish, there is a medical issue called scombroid fish poisoning. It's a foodborne illness caused by eating spoiled or improperly stored fish from the Scombridae family, which includes tuna, mackerel, and bonito, among others. The bacteria present in these fish can produce histamine, which can cause symptoms like skin flushing, headache, diarrhea, and itchy rash. But again, this is not related to the term "fishes" itself but rather a condition associated with consuming certain types of fish.

"Body patterning" is a general term that refers to the process of forming and organizing various tissues and structures into specific patterns during embryonic development. This complex process involves a variety of molecular mechanisms, including gene expression, cell signaling, and cell-cell interactions. It results in the creation of distinct body regions, such as the head, trunk, and limbs, as well as the organization of internal organs and systems.

In medical terminology, "body patterning" may refer to specific developmental processes or abnormalities related to embryonic development. For example, in genetic disorders such as Poland syndrome or Holt-Oram syndrome, mutations in certain genes can lead to abnormal body patterning, resulting in the absence or underdevelopment of certain muscles, bones, or other structures.

It's important to note that "body patterning" is not a formal medical term with a specific definition, but rather a general concept used in developmental biology and genetics.

Biological evolution is the change in the genetic composition of populations of organisms over time, from one generation to the next. It is a process that results in descendants differing genetically from their ancestors. Biological evolution can be driven by several mechanisms, including natural selection, genetic drift, gene flow, and mutation. These processes can lead to changes in the frequency of alleles (variants of a gene) within populations, resulting in the development of new species and the extinction of others over long periods of time. Biological evolution provides a unifying explanation for the diversity of life on Earth and is supported by extensive evidence from many different fields of science, including genetics, paleontology, comparative anatomy, and biogeography.

I'm sorry for any confusion, but "lampreys" is not a medical term. It refers to a type of jawless aquatic vertebrate that are eel-like in appearance. They are parasitic creatures, with a suction cup-like mouth and circular rows of teeth, which they use to attach to fish and suck their body fluids. If you have any questions about medical terminology or concepts, I'd be happy to help with those!

I'm sorry for any confusion, but "hagfishes" are not a medical term. They are a group of marine animals that are considered to be some of the most primitive and ancient of all living jawless fish. Hagfishes are well known for their ability to produce large amounts of slime when threatened, which can help them escape from predators.

If you have any questions about biology or zoology, I'd be happy to try to answer them for you!

I'm sorry for any confusion, but "Reptiles" is not a medical term. It is a term used in biology to describe a class of cold-blooded, scaly-skinned animals that include snakes, lizards, alligators, crocodiles, turtles, and tortoises. They are characterized by having lungs for breathing, laying eggs on land, and having a three-chambered heart. If you have any medical questions or terms, I'd be happy to help clarify those!

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

I'm sorry for any confusion, but "Invertebrates" is not a medical term. It is a term used in biology to describe a vast group of animals that do not have a vertebral column or spinal cord. This includes creatures such as insects, worms, starfish, and shellfish, among many others. They are classified as invertebrates because they lack a backbone, which is a characteristic of vertebrates, or animals that include humans and other mammals, birds, reptiles, amphibians, and fish.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

In situ hybridization (ISH) is a molecular biology technique used to detect and localize specific nucleic acid sequences, such as DNA or RNA, within cells or tissues. This technique involves the use of a labeled probe that is complementary to the target nucleic acid sequence. The probe can be labeled with various types of markers, including radioisotopes, fluorescent dyes, or enzymes.

During the ISH procedure, the labeled probe is hybridized to the target nucleic acid sequence in situ, meaning that the hybridization occurs within the intact cells or tissues. After washing away unbound probe, the location of the labeled probe can be visualized using various methods depending on the type of label used.

In situ hybridization has a wide range of applications in both research and diagnostic settings, including the detection of gene expression patterns, identification of viral infections, and diagnosis of genetic disorders.

"Xenopus proteins" refer to the proteins that are expressed or isolated from the Xenopus species, which are primarily used as model organisms in biological and biomedical research. The most commonly used Xenopus species for research are the African clawed frogs, Xenopus laevis and Xenopus tropicalis. These proteins play crucial roles in various cellular processes and functions, and they serve as valuable tools to study different aspects of molecular biology, developmental biology, genetics, and biochemistry.

Some examples of Xenopus proteins that are widely studied include:

1. Xenopus Histones: These are the proteins that package DNA into nucleosomes, which are the fundamental units of chromatin in eukaryotic cells. They play a significant role in gene regulation and epigenetic modifications.
2. Xenopus Cyclins and Cyclin-dependent kinases (CDKs): These proteins regulate the cell cycle and control cell division, differentiation, and apoptosis.
3. Xenopus Transcription factors: These proteins bind to specific DNA sequences and regulate gene expression during development and in response to various stimuli.
4. Xenopus Signaling molecules: These proteins are involved in intracellular signaling pathways that control various cellular processes, such as cell growth, differentiation, migration, and survival.
5. Xenopus Cytoskeletal proteins: These proteins provide structural support to the cells and regulate their shape, motility, and organization.
6. Xenopus Enzymes: These proteins catalyze various biochemical reactions in the cell, such as metabolic pathways, DNA replication, transcription, and translation.

Overall, Xenopus proteins are essential tools for understanding fundamental biological processes and have contributed significantly to our current knowledge of molecular biology, genetics, and developmental biology.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

A conserved sequence in the context of molecular biology refers to a pattern of nucleotides (in DNA or RNA) or amino acids (in proteins) that has remained relatively unchanged over evolutionary time. These sequences are often functionally important and are highly conserved across different species, indicating strong selection pressure against changes in these regions.

In the case of protein-coding genes, the corresponding amino acid sequence is deduced from the DNA sequence through the genetic code. Conserved sequences in proteins may indicate structurally or functionally important regions, such as active sites or binding sites, that are critical for the protein's activity. Similarly, conserved non-coding sequences in DNA may represent regulatory elements that control gene expression.

Identifying conserved sequences can be useful for inferring evolutionary relationships between species and for predicting the function of unknown genes or proteins.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

Amphibians are a class of cold-blooded vertebrates that include frogs, toads, salamanders, newts, and caecilians. They are characterized by their four-limbed body structure, moist skin, and double circulation system with three-chambered hearts. Amphibians are unique because they have a life cycle that involves two distinct stages: an aquatic larval stage (usually as a tadpole or larva) and a terrestrial adult stage. They typically start their lives in water, undergoing metamorphosis to develop lungs and legs for a land-dwelling existence. Many amphibians are also known for their complex reproductive behaviors and vocalizations.

Chordata is a phylum in the animal kingdom that contains animals with notochords, dorsal hollow nerve cords, pharyngeal gill slits, and post-anal tails at some point during their development. This phylum includes organisms that are bilaterally symmetrical, have a coelom (a body cavity), and are triploblastic (having three germ layers: ectoderm, mesoderm, and endoderm).

The Chordata phylum is divided into three subphyla: Urochordata (tunicates or sea squirts), Cephalochordata (lancelets or amphioxi), and Vertebrata (animals with backbones, including fish, amphibians, reptiles, birds, and mammals). The presence of the notochord, a flexible, rod-like structure that runs along the length of the body, is a key characteristic that unites these diverse groups.

In vertebrates, the notochord is replaced during development by the spinal column or backbone, which provides support and protection for the central nervous system. The dorsal hollow nerve cord develops into the brain and spinal cord in vertebrates, while pharyngeal gill slits are modified into various structures such as the tonsils, thymus, and middle ear bones in different vertebrate groups.

Overall, Chordata represents a diverse group of organisms with shared developmental features that have evolved to adapt to various ecological niches throughout history.

Homeodomain proteins are a group of transcription factors that play crucial roles in the development and differentiation of cells in animals and plants. They are characterized by the presence of a highly conserved DNA-binding domain called the homeodomain, which is typically about 60 amino acids long. The homeodomain consists of three helices, with the third helix responsible for recognizing and binding to specific DNA sequences.

Homeodomain proteins are involved in regulating gene expression during embryonic development, tissue maintenance, and organismal growth. They can act as activators or repressors of transcription, depending on the context and the presence of cofactors. Mutations in homeodomain proteins have been associated with various human diseases, including cancer, congenital abnormalities, and neurological disorders.

Some examples of homeodomain proteins include PAX6, which is essential for eye development, HOX genes, which are involved in body patterning, and NANOG, which plays a role in maintaining pluripotency in stem cells.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

'Ciona intestinalis' is a species of tunicate, also known as sea squirts. They are marine invertebrate animals that are characterized by their sac-like bodies and filter-feeding habits. Tunicates are members of the phylum Chordata, which includes all animals with dorsal, hollow nerve cords – a category that also contains vertebrates (animals with backbones).

'Ciona intestinalis' is often used as a model organism in biological research due to its simple anatomy and relatively small genome. It has been studied in various fields such as developmental biology, evolution, and biomedical research. The species is native to the waters of the North Atlantic Ocean but has been introduced to many other regions around the world.

I'm sorry for any confusion, but "sharks" are not a medical term. Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral and dorsal fins without spines.

If you have any medical questions or terms that you would like defined, I'd be happy to help!

"Oryzias" is not a medical term, but a genus name in the family Adrianichthyidae, which includes various species of small fish commonly known as "ricefishes" or "medaka." These fish are often used in scientific research, particularly in the fields of genetics and developmental biology. They are not associated with human diseases or medical conditions.

"Takifugu" is not a medical term, but a genus of pufferfish found in the waters of East Asia. However, some people may use it to refer to "pufferfish poisoning," which is a type of food poisoning caused by the consumption of pufferfish that contain a potent neurotoxin called tetrodotoxin. This toxin is found in the fish's organs, such as the liver and ovaries, and can be deadly if ingested in large quantities. Proper preparation and cooking of pufferfish by trained chefs can make it safe to eat, but it is still considered a delicacy with significant risks.

Gene duplication, in the context of genetics and genomics, refers to an event where a segment of DNA that contains a gene is copied, resulting in two identical copies of that gene. This can occur through various mechanisms such as unequal crossing over during meiosis, retrotransposition, or whole genome duplication. The duplicate genes are then passed on to the next generation.

Gene duplications can have several consequences. Often, one copy may continue to function normally while the other is free to mutate without affecting the organism's survival, potentially leading to new functions (neofunctionalization) or subfunctionalization where each copy takes on some of the original gene's roles.

Gene duplication plays a significant role in evolution by providing raw material for the creation of novel genes and genetic diversity. However, it can also lead to various genetic disorders if multiple copies of a gene become dysfunctional or if there are too many copies, leading to an overdose effect.

"Petromyzon" is the name of a genus that includes the sea lampreys, an ancient type of jawless fish. They are eel-like aquatic creatures with circular mouths filled with teeth, which they use to attach themselves to other fish and feed on their blood. They have a long, slender body, and can grow up to 20-100 cm in length depending on the species. Sea lampreys are considered parasites and can cause significant damage to commercial fisheries.

"Xenopus" is not a medical term, but it is a genus of highly invasive aquatic frogs native to sub-Saharan Africa. They are often used in scientific research, particularly in developmental biology and genetics. The most commonly studied species is Xenopus laevis, also known as the African clawed frog.

In a medical context, Xenopus might be mentioned when discussing their use in research or as a model organism to study various biological processes or diseases.

A genome is the complete set of genetic material (DNA, or in some viruses, RNA) present in a single cell of an organism. It includes all of the genes, both coding and noncoding, as well as other regulatory elements that together determine the unique characteristics of that organism. The human genome, for example, contains approximately 3 billion base pairs and about 20,000-25,000 protein-coding genes.

The term "genome" was first coined by Hans Winkler in 1920, derived from the word "gene" and the suffix "-ome," which refers to a complete set of something. The study of genomes is known as genomics.

Understanding the genome can provide valuable insights into the genetic basis of diseases, evolution, and other biological processes. With advancements in sequencing technologies, it has become possible to determine the entire genomic sequence of many organisms, including humans, and use this information for various applications such as personalized medicine, gene therapy, and biotechnology.

Genetically modified animals (GMAs) are those whose genetic makeup has been altered using biotechnological techniques. This is typically done by introducing one or more genes from another species into the animal's genome, resulting in a new trait or characteristic that does not naturally occur in that species. The introduced gene is often referred to as a transgene.

The process of creating GMAs involves several steps:

1. Isolation: The desired gene is isolated from the DNA of another organism.
2. Transfer: The isolated gene is transferred into the target animal's cells, usually using a vector such as a virus or bacterium.
3. Integration: The transgene integrates into the animal's chromosome, becoming a permanent part of its genetic makeup.
4. Selection: The modified cells are allowed to multiply, and those that contain the transgene are selected for further growth and development.
5. Breeding: The genetically modified individuals are bred to produce offspring that carry the desired trait.

GMAs have various applications in research, agriculture, and medicine. In research, they can serve as models for studying human diseases or testing new therapies. In agriculture, GMAs can be developed to exhibit enhanced growth rates, improved disease resistance, or increased nutritional value. In medicine, GMAs may be used to produce pharmaceuticals or other therapeutic agents within their bodies.

Examples of genetically modified animals include mice with added genes for specific proteins that make them useful models for studying human diseases, goats that produce a human protein in their milk to treat hemophilia, and pigs with enhanced resistance to certain viruses that could potentially be used as organ donors for humans.

It is important to note that the use of genetically modified animals raises ethical concerns related to animal welfare, environmental impact, and potential risks to human health. These issues must be carefully considered and addressed when developing and implementing GMA technologies.

Mammals are a group of warm-blooded vertebrates constituting the class Mammalia, characterized by the presence of mammary glands (which produce milk to feed their young), hair or fur, three middle ear bones, and a neocortex region in their brain. They are found in a diverse range of habitats and come in various sizes, from tiny shrews to large whales. Examples of mammals include humans, apes, monkeys, dogs, cats, bats, mice, raccoons, seals, dolphins, horses, and elephants.

A chick embryo refers to the developing organism that arises from a fertilized chicken egg. It is often used as a model system in biological research, particularly during the stages of development when many of its organs and systems are forming and can be easily observed and manipulated. The study of chick embryos has contributed significantly to our understanding of various aspects of developmental biology, including gastrulation, neurulation, organogenesis, and pattern formation. Researchers may use various techniques to observe and manipulate the chick embryo, such as surgical alterations, cell labeling, and exposure to drugs or other agents.

Homeobox genes are a specific class of genes that play a crucial role in the development and regulation of an organism's body plan. They encode transcription factors, which are proteins that regulate the expression of other genes. The homeobox region within these genes contains a highly conserved sequence of about 180 base pairs that encodes a DNA-binding domain called the homeodomain. This domain is responsible for recognizing and binding to specific DNA sequences, thereby controlling the transcription of target genes.

Homeobox genes are particularly important during embryonic development, where they help establish the anterior-posterior axis and regulate the development of various organs and body segments. They also play a role in maintaining adult tissue homeostasis and have been implicated in certain diseases, including cancer. Mutations in homeobox genes can lead to developmental abnormalities and congenital disorders.

Some examples of homeobox gene families include HOX genes, PAX genes, and NKX genes, among others. These genes are highly conserved across species, indicating their fundamental role in the development and regulation of body plans throughout the animal kingdom.

'Drosophila proteins' refer to the proteins that are expressed in the fruit fly, Drosophila melanogaster. This organism is a widely used model system in genetics, developmental biology, and molecular biology research. The study of Drosophila proteins has contributed significantly to our understanding of various biological processes, including gene regulation, cell signaling, development, and aging.

Some examples of well-studied Drosophila proteins include:

1. HSP70 (Heat Shock Protein 70): A chaperone protein involved in protein folding and protection from stress conditions.
2. TUBULIN: A structural protein that forms microtubules, important for cell division and intracellular transport.
3. ACTIN: A cytoskeletal protein involved in muscle contraction, cell motility, and maintenance of cell shape.
4. BETA-GALACTOSIDASE (LACZ): A reporter protein often used to monitor gene expression patterns in transgenic flies.
5. ENDOGLIN: A protein involved in the development of blood vessels during embryogenesis.
6. P53: A tumor suppressor protein that plays a crucial role in preventing cancer by regulating cell growth and division.
7. JUN-KINASE (JNK): A signaling protein involved in stress response, apoptosis, and developmental processes.
8. DECAPENTAPLEGIC (DPP): A member of the TGF-β (Transforming Growth Factor Beta) superfamily, playing essential roles in embryonic development and tissue homeostasis.

These proteins are often studied using various techniques such as biochemistry, genetics, molecular biology, and structural biology to understand their functions, interactions, and regulation within the cell.

"Xenopus laevis" is not a medical term itself, but it refers to a specific species of African clawed frog that is often used in scientific research, including biomedical and developmental studies. Therefore, its relevance to medicine comes from its role as a model organism in laboratories.

In a broader sense, Xenopus laevis has contributed significantly to various medical discoveries, such as the understanding of embryonic development, cell cycle regulation, and genetic research. For instance, the Nobel Prize in Physiology or Medicine was awarded in 1963 to John R. B. Gurdon and Sir Michael J. Bishop for their discoveries concerning the genetic mechanisms of organism development using Xenopus laevis as a model system.

Urochordata is a phylum in the animal kingdom that includes sessile, marine organisms commonly known as tunicates or sea squirts. The name "Urochordata" means "tail-cord animals," which refers to the notochord, a flexible, rod-like structure found in the tails of these animals during their larval stage.

Tunicates are filter feeders that draw water into their bodies through a siphon and extract plankton and other organic particles for nutrition. They have a simple body plan, consisting of a protective outer covering called a tunic, an inner body mass with a muscular pharynx, and a tail-like structure called the post-anal tail.

Urochordates are of particular interest to biologists because they are considered to be the closest living relatives to vertebrates (animals with backbones), sharing a common ancestor with them around 550 million years ago. Despite their simple appearance, tunicates have complex developmental processes that involve the formation of notochords, dorsal nerve cords, and other structures that are similar to those found in vertebrate embryos.

Overall, Urochordata is a fascinating phylum that provides important insights into the evolutionary history of animals and their diverse body plans.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

"Drosophila" is a genus of small flies, also known as fruit flies. The most common species used in scientific research is "Drosophila melanogaster," which has been a valuable model organism for many areas of biological and medical research, including genetics, developmental biology, neurobiology, and aging.

The use of Drosophila as a model organism has led to numerous important discoveries in genetics and molecular biology, such as the identification of genes that are associated with human diseases like cancer, Parkinson's disease, and obesity. The short reproductive cycle, large number of offspring, and ease of genetic manipulation make Drosophila a powerful tool for studying complex biological processes.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

Morphogenesis is a term used in developmental biology and refers to the process by which cells give rise to tissues and organs with specific shapes, structures, and patterns during embryonic development. This process involves complex interactions between genes, cells, and the extracellular environment that result in the coordinated movement and differentiation of cells into specialized functional units.

Morphogenesis is a dynamic and highly regulated process that involves several mechanisms, including cell proliferation, death, migration, adhesion, and differentiation. These processes are controlled by genetic programs and signaling pathways that respond to environmental cues and regulate the behavior of individual cells within a developing tissue or organ.

The study of morphogenesis is important for understanding how complex biological structures form during development and how these processes can go awry in disease states such as cancer, birth defects, and degenerative disorders.

"Fish proteins" are not a recognized medical term or concept. However, fish is a source of protein that is often consumed in the human diet and has been studied in various medical and nutritional contexts. According to the USDA FoodData Central database, a 100-gram serving of cooked Atlantic salmon contains approximately 25 grams of protein.

Proteins from fish, like other animal proteins, are complete proteins, meaning they contain all nine essential amino acids that cannot be synthesized by the human body and must be obtained through the diet. Fish proteins have been studied for their potential health benefits, including their role in muscle growth and repair, immune function, and cardiovascular health.

It's worth noting that some people may have allergies to fish or seafood, which can cause a range of symptoms from mild skin irritation to severe anaphylaxis. If you suspect you have a fish allergy, it's important to consult with a healthcare professional for proper diagnosis and management.

I apologize for any confusion, but "lizards" is not a term used in medical definition. Lizards are a group of scaled reptiles constituting the order Squamata, characterized by having skin covered with overlapping scales, external ears, and movable eyelids. They are found worldwide in a variety of habitats, ranging from desert to tropical environments. If you have any questions related to medical terminology or health concerns, I'd be happy to help!

I am not aware of a medical definition for the term "birds." Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, and lightweight but strong skeletons. Some birds, such as pigeons and chickens, have been used in medical research, but the term "birds" itself does not have a specific medical definition.

Tetraodontiformes is not a medical term, but a taxonomic order in zoology. It refers to a group of marine fish that includes pufferfish, porcupinefish, boxfish, and triggerfish, among others. These fish are characterized by their specialized teeth, which are fused into beak-like structures. Some species within this order contain tetrodotoxin, a potent neurotoxin, in their organs. While not directly related to medical terminology, it is important for healthcare providers and medical professionals to have an understanding of various animal taxonomies, especially those that can pose a risk to human health.

Synteny, in the context of genetics and genomics, refers to the presence of two or more genetic loci (regions) on the same chromosome, in the same relative order and orientation. This term is often used to describe conserved gene organization between different species, indicating a common ancestry.

It's important to note that synteny should not be confused with "colinearity," which refers to the conservation of gene content and order within a genome or between genomes of closely related species. Synteny is a broader concept that can also include conserved gene order across more distantly related species, even if some genes have been lost or gained in the process.

In medical research, synteny analysis can be useful for identifying conserved genetic elements and regulatory regions that may play important roles in disease susceptibility or other biological processes.

Photoreceptor cells in vertebrates are specialized types of neurons located in the retina of the eye that are responsible for converting light stimuli into electrical signals. These cells are primarily responsible for the initial process of vision and have two main types: rods and cones.

Rods are more numerous and are responsible for low-light vision or scotopic vision, enabling us to see in dimly lit conditions. They do not contribute to color vision but provide information about the shape and movement of objects.

Cones, on the other hand, are less numerous and are responsible for color vision and high-acuity vision or photopic vision. There are three types of cones, each sensitive to different wavelengths of light: short (S), medium (M), and long (L) wavelengths, which correspond to blue, green, and red, respectively. The combination of signals from these three types of cones allows us to perceive a wide range of colors.

Both rods and cones contain photopigments that consist of a protein called opsin and a light-sensitive chromophore called retinal. When light hits the photopigment, it triggers a series of chemical reactions that ultimately lead to the generation of an electrical signal that is transmitted to the brain via the optic nerve. This process enables us to see and perceive our visual world.

In medical and embryological terms, the mesoderm is one of the three primary germ layers in the very early stages of embryonic development. It forms between the ectoderm and endoderm during gastrulation, and it gives rise to a wide variety of cell types, tissues, and organs in the developing embryo.

The mesoderm contributes to the formation of structures such as:

1. The connective tissues (including tendons, ligaments, and most of the bones)
2. Muscular system (skeletal, smooth, and cardiac muscles)
3. Circulatory system (heart, blood vessels, and blood cells)
4. Excretory system (kidneys and associated structures)
5. Reproductive system (gonads, including ovaries and testes)
6. Dermis of the skin
7. Parts of the eye and inner ear
8. Several organs in the urogenital system

Dysfunctions or abnormalities in mesoderm development can lead to various congenital disorders and birth defects, highlighting its importance during embryogenesis.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

The term "extremities" in a medical context refers to the most distant parts of the body, including the hands and feet (both fingers and toes), as well as the arms and legs. These are the farthest parts from the torso and head. Medical professionals may examine a patient's extremities for various reasons, such as checking circulation, assessing nerve function, or looking for injuries or abnormalities.

The rhombencephalon is a term used in the field of neuroanatomy, which refers to the most posterior region of the developing brain during embryonic development. It is also known as the hindbrain and it gives rise to several important structures in the adult brain.

More specifically, the rhombencephalon can be further divided into two main parts: the metencephalon and the myelencephalon. The metencephalon eventually develops into the pons and cerebellum, while the myelencephalon becomes the medulla oblongata.

The rhombencephalon plays a crucial role in several critical functions of the nervous system, including regulating heart rate and respiration, maintaining balance and posture, and coordinating motor movements. Defects or abnormalities in the development of the rhombencephalon can lead to various neurological disorders, such as cerebellar hypoplasia, Chiari malformation, and certain forms of brainstem tumors.

I'm not aware of a specific medical definition for "Avian Proteins." The term "avian" generally refers to birds or their characteristics. Therefore, "avian proteins" would likely refer to proteins that are found in birds or are produced by avian cells. These proteins could have various functions and roles, depending on the specific protein in question.

For example, avian proteins might be of interest in medical research if they have similarities to human proteins and can be used as models to study protein function, structure, or interaction with other molecules. Additionally, some avian proteins may have potential applications in therapeutic development, such as using chicken egg-derived proteins for wound healing or as vaccine components.

However, without a specific context or reference, it's difficult to provide a more precise definition of "avian proteins" in a medical context.

A gastrula is a stage in the early development of many animals, including humans, that occurs following fertilization and cleavage of the zygote. During this stage, the embryo undergoes a process called gastrulation, which involves a series of cell movements that reorganize the embryo into three distinct layers: the ectoderm, mesoderm, and endoderm. These germ layers give rise to all the different tissues and organs in the developing organism.

The gastrula is characterized by the presence of a central cavity called the archenteron, which will eventually become the gut or gastrointestinal tract. The opening of the archenteron is called the blastopore, which will give rise to either the mouth or anus, depending on the animal group.

In summary, a gastrula is a developmental stage in which an embryo undergoes gastrulation to form three germ layers and a central cavity, which will eventually develop into various organs and tissues of the body.

A larva is a distinct stage in the life cycle of various insects, mites, and other arthropods during which they undergo significant metamorphosis before becoming adults. In a medical context, larvae are known for their role in certain parasitic infections. Specifically, some helminth (parasitic worm) species use larval forms to infect human hosts. These invasions may lead to conditions such as cutaneous larva migrans, visceral larva migrans, or gnathostomiasis, depending on the specific parasite involved and the location of the infection within the body.

The larval stage is characterized by its markedly different morphology and behavior compared to the adult form. Larvae often have a distinct appearance, featuring unsegmented bodies, simple sense organs, and undeveloped digestive systems. They are typically adapted for a specific mode of life, such as free-living or parasitic existence, and rely on external sources of nutrition for their development.

In the context of helminth infections, larvae may be transmitted to humans through various routes, including ingestion of contaminated food or water, direct skin contact with infective stages, or transmission via an intermediate host (such as a vector). Once inside the human body, these parasitic larvae can cause tissue damage and provoke immune responses, leading to the clinical manifestations of disease.

It is essential to distinguish between the medical definition of 'larva' and its broader usage in biology and zoology. In those fields, 'larva' refers to any juvenile form that undergoes metamorphosis before reaching adulthood, regardless of whether it is parasitic or not.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

The nervous system is a complex, highly organized network of specialized cells called neurons and glial cells that communicate with each other via electrical and chemical signals to coordinate various functions and activities in the body. It consists of two main parts: the central nervous system (CNS), including the brain and spinal cord, and the peripheral nervous system (PNS), which includes all the nerves and ganglia outside the CNS.

The primary function of the nervous system is to receive, process, and integrate information from both internal and external environments and then respond by generating appropriate motor outputs or behaviors. This involves sensing various stimuli through specialized receptors, transmitting this information through afferent neurons to the CNS for processing, integrating this information with other inputs and memories, making decisions based on this processed information, and finally executing responses through efferent neurons that control effector organs such as muscles and glands.

The nervous system can be further divided into subsystems based on their functions, including the somatic nervous system, which controls voluntary movements and reflexes; the autonomic nervous system, which regulates involuntary physiological processes like heart rate, digestion, and respiration; and the enteric nervous system, which is a specialized subset of the autonomic nervous system that controls gut functions. Overall, the nervous system plays a critical role in maintaining homeostasis, regulating behavior, and enabling cognition and consciousness.

In medical terms, the jaw is referred to as the mandible (in humans and some other animals), which is the lower part of the face that holds the lower teeth in place. It's a large, horseshoe-shaped bone that forms the lower jaw and serves as a attachment point for several muscles that are involved in chewing and moving the lower jaw.

In addition to the mandible, the upper jaw is composed of two bones known as the maxillae, which fuse together at the midline of the face to form the upper jaw. The upper jaw holds the upper teeth in place and forms the roof of the mouth, as well as a portion of the eye sockets and nasal cavity.

Together, the mandible and maxillae allow for various functions such as speaking, eating, and breathing.

Ectoderm is the outermost of the three primary germ layers in a developing embryo, along with the endoderm and mesoderm. The ectoderm gives rise to the outer covering of the body, including the skin, hair, nails, glands, and the nervous system, which includes the brain, spinal cord, and peripheral nerves. It also forms the lining of the mouth, anus, nose, and ears. Essentially, the ectoderm is responsible for producing all the epidermal structures and the neural crest cells that contribute to various derivatives such as melanocytes, adrenal medulla, smooth muscle, and peripheral nervous system components.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

The neural crest is a transient, multipotent embryonic cell population that originates from the ectoderm (outermost layer) of the developing neural tube (precursor to the central nervous system). These cells undergo an epithelial-to-mesenchymal transition and migrate throughout the embryo, giving rise to a diverse array of cell types and structures.

Neural crest cells differentiate into various tissues, including:

1. Peripheral nervous system (PNS) components: sensory neurons, sympathetic and parasympathetic ganglia, and glial cells (e.g., Schwann cells).
2. Facial bones and cartilage, as well as connective tissue of the skull.
3. Melanocytes, which are pigment-producing cells in the skin.
4. Smooth muscle cells in major blood vessels, heart, gastrointestinal tract, and other organs.
5. Secretory cells in endocrine glands (e.g., chromaffin cells of the adrenal medulla).
6. Parts of the eye, such as the cornea and iris stroma.
7. Dental tissues, including dentin, cementum, and dental pulp.

Due to their wide-ranging contributions to various tissues and organs, neural crest cells play a crucial role in embryonic development and organogenesis. Abnormalities in neural crest cell migration or differentiation can lead to several congenital disorders, such as neurocristopathies.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Embryonic development is the series of growth and developmental stages that occur during the formation and early growth of the embryo. In humans, this stage begins at fertilization (when the sperm and egg cell combine) and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (now called a zygote) divides and forms a blastocyst, which then implants into the uterus. The cells in the blastocyst begin to differentiate and form the three germ layers: the ectoderm, mesoderm, and endoderm. These germ layers will eventually give rise to all of the different tissues and organs in the body.

Embryonic development is a complex and highly regulated process that involves the coordinated interaction of genetic and environmental factors. It is characterized by rapid cell division, migration, and differentiation, as well as programmed cell death (apoptosis) and tissue remodeling. Abnormalities in embryonic development can lead to birth defects or other developmental disorders.

It's important to note that the term "embryo" is used to describe the developing organism from fertilization until the end of the 8th week of pregnancy in humans, after which it is called a fetus.

I'm sorry for any confusion, but "turtles" is not a medical term. It refers to the group of reptiles that have a shell and include various species such as tortoises and terrapins. If you have any medical concerns or questions, I would be happy to try to help with those!

DNA Sequence Analysis is the systematic determination of the order of nucleotides in a DNA molecule. It is a critical component of modern molecular biology, genetics, and genetic engineering. The process involves determining the exact order of the four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - in a DNA molecule or fragment. This information is used in various applications such as identifying gene mutations, studying evolutionary relationships, developing molecular markers for breeding, and diagnosing genetic diseases.

The process of DNA Sequence Analysis typically involves several steps, including DNA extraction, PCR amplification (if necessary), purification, sequencing reaction, and electrophoresis. The resulting data is then analyzed using specialized software to determine the exact sequence of nucleotides.

In recent years, high-throughput DNA sequencing technologies have revolutionized the field of genomics, enabling the rapid and cost-effective sequencing of entire genomes. This has led to an explosion of genomic data and new insights into the genetic basis of many diseases and traits.

In medical terms, "fossils" do not have a specific or direct relevance to the field. However, in a broader scientific context, fossils are the remains or impressions of prehistoric organisms preserved in petrified form or as a mold or cast in rock. They offer valuable evidence about the Earth's history and the life forms that existed on it millions of years ago.

Paleopathology is a subfield of paleontology that deals with the study of diseases in fossils, which can provide insights into the evolution of diseases and human health over time.

Embryonic induction is a process that occurs during the development of a multicellular organism, where one group of cells in the embryo signals and influences the developmental fate of another group of cells. This interaction leads to the formation of specific structures or organs in the developing embryo. The signaling cells that initiate the process are called organizers, and they release signaling molecules known as morphogens that bind to receptors on the target cells and trigger a cascade of intracellular signals that ultimately lead to changes in gene expression and cell fate. Embryonic induction is a crucial step in the development of complex organisms and plays a key role in establishing the body plan and organizing the different tissues and organs in the developing embryo.

DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.

The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.

DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

Wnt proteins are a family of secreted signaling molecules that play crucial roles in the regulation of fundamental biological processes, including cell proliferation, differentiation, migration, and survival. They were first discovered in 1982 through genetic studies in Drosophila melanogaster (fruit flies) and have since been found to be highly conserved across various species, from invertebrates to humans.

Wnt proteins exert their effects by binding to specific receptors on the target cell surface, leading to the activation of several intracellular signaling pathways:

1. Canonical Wnt/β-catenin pathway: In the absence of Wnt ligands, β-catenin is continuously degraded by a destruction complex consisting of Axin, APC (Adenomatous polyposis coli), and GSK3β (Glycogen synthase kinase 3 beta). When Wnt proteins bind to their receptors Frizzled and LRP5/6, the formation of a "signalosome" complex leads to the inhibition of the destruction complex, allowing β-catenin to accumulate in the cytoplasm and translocate into the nucleus. Here, it interacts with TCF/LEF (T-cell factor/lymphoid enhancer-binding factor) transcription factors to regulate the expression of target genes involved in cell proliferation, differentiation, and survival.
2. Non-canonical Wnt pathways: These include the Wnt/Ca^2+^ pathway and the planar cell polarity (PCP) pathway. In the Wnt/Ca^2+^ pathway, Wnt ligands bind to Frizzled receptors and activate heterotrimeric G proteins, leading to an increase in intracellular Ca^2+^ levels and activation of downstream targets such as protein kinase C (PKC) and calcium/calmodulin-dependent protein kinase II (CAMKII). These signaling events ultimately regulate cell movement, adhesion, and gene expression. In the PCP pathway, Wnt ligands bind to Frizzled receptors and coreceptor complexes containing Ror2 or Ryk, leading to activation of small GTPases such as RhoA and Rac1, which control cytoskeletal organization and cell polarity.

Dysregulation of Wnt signaling has been implicated in various human diseases, including cancer, developmental disorders, and degenerative conditions. In cancer, aberrant activation of the canonical Wnt/β-catenin pathway contributes to tumor initiation, progression, and metastasis by promoting cell proliferation, survival, and epithelial-mesenchymal transition (EMT). Inhibitors targeting different components of the Wnt signaling pathway are currently being developed as potential therapeutic strategies for cancer treatment.

The eye is the organ of sight, primarily responsible for detecting and focusing on visual stimuli. It is a complex structure composed of various parts that work together to enable vision. Here are some of the main components of the eye:

1. Cornea: The clear front part of the eye that refracts light entering the eye and protects the eye from harmful particles and microorganisms.
2. Iris: The colored part of the eye that controls the amount of light reaching the retina by adjusting the size of the pupil.
3. Pupil: The opening in the center of the iris that allows light to enter the eye.
4. Lens: A biconvex structure located behind the iris that further refracts light and focuses it onto the retina.
5. Retina: A layer of light-sensitive cells (rods and cones) at the back of the eye that convert light into electrical signals, which are then transmitted to the brain via the optic nerve.
6. Optic Nerve: The nerve that carries visual information from the retina to the brain.
7. Vitreous: A clear, gel-like substance that fills the space between the lens and the retina, providing structural support to the eye.
8. Conjunctiva: A thin, transparent membrane that covers the front of the eye and the inner surface of the eyelids.
9. Extraocular Muscles: Six muscles that control the movement of the eye, allowing for proper alignment and focus.

The eye is a remarkable organ that allows us to perceive and interact with our surroundings. Various medical specialties, such as ophthalmology and optometry, are dedicated to the diagnosis, treatment, and management of various eye conditions and diseases.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

The retina is the innermost, light-sensitive layer of tissue in the eye of many vertebrates and some cephalopods. It receives light that has been focused by the cornea and lens, converts it into neural signals, and sends these to the brain via the optic nerve. The retina contains several types of photoreceptor cells including rods (which handle vision in low light) and cones (which are active in bright light and are capable of color vision).

In medical terms, any pathological changes or diseases affecting the retinal structure and function can lead to visual impairment or blindness. Examples include age-related macular degeneration, diabetic retinopathy, retinal detachment, and retinitis pigmentosa among others.

I'm sorry for any confusion, but "Goldfish" is not a term used in medical definitions. Goldfish are small domesticated fish that are often kept as pets. They belong to the family Cyprinidae and the genus Carassius. The most common species of goldfish is Carassius auratus. If you have any questions about goldfish or their care, I might be able to help with some general information, but for specific medical concerns, it would be best to consult a veterinarian.

The Central Nervous System (CNS) is the part of the nervous system that consists of the brain and spinal cord. It is called the "central" system because it receives information from, and sends information to, the rest of the body through peripheral nerves, which make up the Peripheral Nervous System (PNS).

The CNS is responsible for processing sensory information, controlling motor functions, and regulating various autonomic processes like heart rate, respiration, and digestion. The brain, as the command center of the CNS, interprets sensory stimuli, formulates thoughts, and initiates actions. The spinal cord serves as a conduit for nerve impulses traveling to and from the brain and the rest of the body.

The CNS is protected by several structures, including the skull (which houses the brain) and the vertebral column (which surrounds and protects the spinal cord). Despite these protective measures, the CNS remains vulnerable to injury and disease, which can have severe consequences due to its crucial role in controlling essential bodily functions.

Opsins are a type of protein that are sensitive to light and play a crucial role in vision. They are found in the photoreceptor cells of the retina, which are the specialized cells in the eye that detect light. Opsins are activated by light, which triggers a series of chemical reactions that ultimately result in the transmission of a signal to the brain, allowing us to see.

There are several different types of opsins, including rhodopsin and the cone pigments, which are found in the rods and cones of the retina, respectively. Rhodopsin is responsible for dim-light vision, while the cone pigments are involved in color vision and bright-light vision.

Opsins belong to a larger family of proteins called G protein-coupled receptors (GPCRs), which are involved in many different physiological processes in the body. In addition to their role in vision, opsins have also been found to be involved in other light-dependent processes, such as the regulation of circadian rhythms and the entrainment of the biological clock.

Urodela is not a medical term, but a taxonomic category in the field of biology. It refers to a group of amphibians commonly known as newts and salamanders. These creatures are characterized by their slender bodies, moist skin, and four legs. They undergo a process of metamorphosis during their development, transitioning from an aquatic larval stage to a terrestrial adult stage.

While not a medical term itself, understanding the biology and ecology of Urodela can be relevant in fields such as environmental health and toxicology, where these animals may serve as indicators of ecosystem health or potential subjects for studying the effects of pollutants on living organisms.

Paired box (PAX) transcription factors are a group of proteins that regulate gene expression during embryonic development and in some adult tissues. They are characterized by the presence of a paired box domain, a conserved DNA-binding motif that recognizes specific DNA sequences. PAX proteins play crucial roles in various developmental processes, such as the formation of the nervous system, eyes, and pancreas. Dysregulation of PAX genes has been implicated in several human diseases, including cancer.

Bone Morphogenetic Proteins (BMPs) are a group of growth factors that play crucial roles in the development, growth, and repair of bones and other tissues. They belong to the Transforming Growth Factor-β (TGF-β) superfamily and were first discovered when researchers found that certain proteins extracted from demineralized bone matrix had the ability to induce new bone formation.

BMPs stimulate the differentiation of mesenchymal stem cells into osteoblasts, which are the cells responsible for bone formation. They also promote the recruitment and proliferation of these cells, enhancing the overall process of bone regeneration. In addition to their role in bone biology, BMPs have been implicated in various other biological processes, including embryonic development, wound healing, and the regulation of fat metabolism.

There are several types of BMPs (BMP-2, BMP-4, BMP-7, etc.) that exhibit distinct functions and expression patterns. Due to their ability to stimulate bone formation, recombinant human BMPs have been used in clinical applications, such as spinal fusion surgery and non-healing fracture treatment. However, the use of BMPs in medicine has been associated with certain risks and complications, including uncontrolled bone growth, inflammation, and cancer development, which necessitates further research to optimize their therapeutic potential.

"Ranidae" is not a medical term. It is a biological term that refers to a family of frogs and toads, commonly known as "true frogs." These amphibians are characterized by their long legs, webbed feet, and the ability to live both in water and on land. Some examples of ranids include the American bullfrog and the green frog.

Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.

Genetic models are theoretical frameworks used in genetics to describe and explain the inheritance patterns and genetic architecture of traits, diseases, or phenomena. These models are based on mathematical equations and statistical methods that incorporate information about gene frequencies, modes of inheritance, and the effects of environmental factors. They can be used to predict the probability of certain genetic outcomes, to understand the genetic basis of complex traits, and to inform medical management and treatment decisions.

There are several types of genetic models, including:

1. Mendelian models: These models describe the inheritance patterns of simple genetic traits that follow Mendel's laws of segregation and independent assortment. Examples include autosomal dominant, autosomal recessive, and X-linked inheritance.
2. Complex trait models: These models describe the inheritance patterns of complex traits that are influenced by multiple genes and environmental factors. Examples include heart disease, diabetes, and cancer.
3. Population genetics models: These models describe the distribution and frequency of genetic variants within populations over time. They can be used to study evolutionary processes, such as natural selection and genetic drift.
4. Quantitative genetics models: These models describe the relationship between genetic variation and phenotypic variation in continuous traits, such as height or IQ. They can be used to estimate heritability and to identify quantitative trait loci (QTLs) that contribute to trait variation.
5. Statistical genetics models: These models use statistical methods to analyze genetic data and infer the presence of genetic associations or linkage. They can be used to identify genetic risk factors for diseases or traits.

Overall, genetic models are essential tools in genetics research and medical genetics, as they allow researchers to make predictions about genetic outcomes, test hypotheses about the genetic basis of traits and diseases, and develop strategies for prevention, diagnosis, and treatment.

'Caenorhabditis elegans' is a species of free-living, transparent nematode (roundworm) that is widely used as a model organism in scientific research, particularly in the fields of biology and genetics. It has a simple anatomy, short lifespan, and fully sequenced genome, making it an ideal subject for studying various biological processes and diseases.

Some notable features of C. elegans include:

* Small size: Adult hermaphrodites are about 1 mm in length.
* Short lifespan: The average lifespan of C. elegans is around 2-3 weeks, although some strains can live up to 4 weeks under laboratory conditions.
* Development: C. elegans has a well-characterized developmental process, with adults developing from eggs in just 3 days at 20°C.
* Transparency: The transparent body of C. elegans allows researchers to observe its internal structures and processes easily.
* Genetics: C. elegans has a fully sequenced genome, which contains approximately 20,000 genes. Many of these genes have human homologs, making it an excellent model for studying human diseases.
* Neurobiology: C. elegans has a simple nervous system, with only 302 neurons in the hermaphrodite and 383 in the male. This simplicity makes it an ideal organism for studying neural development, function, and behavior.

Research using C. elegans has contributed significantly to our understanding of various biological processes, including cell division, apoptosis, aging, learning, and memory. Additionally, studies on C. elegans have led to the discovery of many genes associated with human diseases such as cancer, neurodegenerative disorders, and metabolic conditions.

I'm sorry for any confusion, but "Insect Proteins" is not a recognized medical term. However, I can provide some information about insect protein from a nutritional and food science perspective.

Insect proteins refer to the proteins that are obtained from insects. Insects are a rich source of protein, and their protein content varies by species. For example, mealworms and crickets have been found to contain approximately 47-63% and 60-72% protein by dry weight, respectively.

In recent years, insect proteins have gained attention as a potential sustainable source of nutrition due to their high protein content, low environmental impact, and the ability to convert feed into protein more efficiently compared to traditional livestock. Insect proteins can be used in various applications such as food and feed additives, nutritional supplements, and even cosmetics.

However, it's important to note that the use of insect proteins in human food is not widely accepted in many Western countries due to cultural and regulatory barriers. Nonetheless, research and development efforts continue to explore the potential benefits and applications of insect proteins in the global food system.

I could not find a medical definition for "animal fins" as a single concept. However, in the field of comparative anatomy and evolutionary biology, fins are specialized limbs that some aquatic animals use for movement, stability, or sensory purposes. Fins can be found in various forms among different animal groups, including fish, amphibians, reptiles, and even mammals like whales and dolphins.

Fins consist of either bony or cartilaginous structures that support webs of skin or connective tissue. They may contain muscles, blood vessels, nerves, and sensory organs, which help animals navigate their underwater environment efficiently. The specific structure and function of fins can vary greatly depending on the animal's taxonomic group and lifestyle adaptations.

In a medical context, studying animal fins could provide insights into the evolution of limbs in vertebrates or contribute to the development of biomimetic technologies inspired by nature. However, there is no standalone medical definition for 'animal fins.'

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

The notochord is a flexible, rod-shaped structure that is present in the embryos of chordates, including humans. It is composed of cells called chordocytes and is surrounded by a sheath. The notochord runs along the length of the body, providing support and flexibility. In human embryos, the notochord eventually becomes part of the discs between the vertebrae in the spine. An abnormal or absent notochord can lead to developmental problems with the spine and nervous system.

Developmental biology is a branch of biological research that studies the processes by which organisms grow and develop from fertilized eggs (zygotes) to adults. This field of study encompasses understanding the genetic, epigenetic, environmental, and molecular mechanisms that guide the developmental trajectory of an organism, including cellular differentiation, pattern formation, morphogenesis, and growth control.

Developmental biology has important implications for understanding congenital disorders, regenerative medicine, and evolutionary biology. Researchers in this field use a variety of model organisms, such as fruit flies (Drosophila melanogaster), zebrafish (Danio rerio), mice (Mus musculus), and nematodes (Caenorhabditis elegans), to investigate the fundamental principles that govern developmental processes. These insights can then be applied to understanding human development and disease.

Embryonic organizers are specialized cells or tissues in developing embryos that provide critical signals to guide the organization and development of surrounding cells and tissues. They play a crucial role in establishing the body plan and patterning of the organism during embryogenesis. A well-known example is the Spemann-Mangold organizer, first described in amphibians, which induces the formation of the neural tissue and organizes the surrounding tissues to form the body axis. Embryonic organizers have been identified in various animal models, including mammals, birds, and fish, and they are essential for normal embryonic development.

Eye proteins, also known as ocular proteins, are specific proteins that are found within the eye and play crucial roles in maintaining proper eye function and health. These proteins can be found in various parts of the eye, including the cornea, iris, lens, retina, and other structures. They perform a wide range of functions, such as:

1. Structural support: Proteins like collagen and elastin provide strength and flexibility to the eye's tissues, enabling them to maintain their shape and withstand mechanical stress.
2. Light absorption and transmission: Proteins like opsins and crystallins are involved in capturing and transmitting light signals within the eye, which is essential for vision.
3. Protection against damage: Some eye proteins, such as antioxidant enzymes and heat shock proteins, help protect the eye from oxidative stress, UV radiation, and other environmental factors that can cause damage.
4. Regulation of eye growth and development: Various growth factors and signaling molecules, which are protein-based, contribute to the proper growth, differentiation, and maintenance of eye tissues during embryonic development and throughout adulthood.
5. Immune defense: Proteins involved in the immune response, such as complement components and immunoglobulins, help protect the eye from infection and inflammation.
6. Maintenance of transparency: Crystallin proteins in the lens maintain its transparency, allowing light to pass through unobstructed for clear vision.
7. Neuroprotection: Certain eye proteins, like brain-derived neurotrophic factor (BDNF), support the survival and function of neurons within the retina, helping to preserve vision.

Dysfunction or damage to these eye proteins can contribute to various eye disorders and diseases, such as cataracts, age-related macular degeneration, glaucoma, diabetic retinopathy, and others.

In medical terms, the "head" is the uppermost part of the human body that contains the brain, skull, face, eyes, nose, mouth, and ears. It is connected to the rest of the body by the neck and is responsible for many vital functions such as sight, hearing, smell, taste, touch, and thought processing. The head also plays a crucial role in maintaining balance, speech, and eating.

"Anura" is a term used in the field of zoology, particularly in the study of amphibians. It refers to a order that includes frogs and toads. The name "Anura" comes from the Greek language, with "an-" meaning "without," and "oura" meaning "tail." This is a reference to the fact that members of this order lack tails in their adult form.

The Anura order is characterized by several distinct features:

1. They have short, powerful legs that are well adapted for jumping or leaping.
2. Their forelimbs are smaller and less specialized than their hind limbs.
3. Most anurans have a moist, glandular skin, which helps them to breathe and absorb water.
4. Anura includes both aquatic and terrestrial species, with varying degrees of adaptations for each environment.
5. They lay their eggs in water, and their larvae (tadpoles) are aquatic, undergoing a process called metamorphosis to transform into the adult form.

Anura contains approximately 7,000 known species, making it one of the largest orders of vertebrates. They have a cosmopolitan distribution and can be found on every continent except Antarctica. Anurans play essential roles in many ecosystems as both predators and prey, contributing to the regulation of insect populations and serving as indicators of environmental health.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Limb buds are embryological structures that develop in the early stages of fetal growth and give rise to future limbs. In humans, they appear around the 4th week of gestation as thickenings on the sides of the body trunk. These buds consist of a core of mesenchymal tissue surrounded by ectoderm. The mesenchyme will later differentiate into bones, muscles, tendons, ligaments, and cartilages, while the ectoderm will form the skin and nervous tissues, including sensory organs in the limbs.

The development of limb buds is regulated by a complex interplay of genetic and molecular factors that control their outgrowth, patterning, and differentiation into specific limb components. Abnormalities during this process can lead to various congenital limb defects or deformations.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Rhodopsin, also known as visual purple, is a light-sensitive protein found in the rods of the eye's retina. It is a type of opsin, a class of proteins that are activated by light and play a crucial role in vision. Rhodopsin is composed of two parts: an apoprotein called opsin and a chromophore called 11-cis-retinal. When light hits the retina, it changes the shape of the 11-cis-retinal, which in turn activates the rhodopsin protein. This activation triggers a series of chemical reactions that ultimately lead to the transmission of a visual signal to the brain. Rhodopsin is highly sensitive to light and allows for vision in low-light conditions.

A "dogfish" is a common name that refers to several species of small sharks. The term is not a formal medical or scientific term, but rather a colloquial one used to describe these marine animals. There are two main types of dogfish: the spiny dogfish (Squalus acanthias) and the smooth dogfish (Mustelus canis).

The spiny dogfish is characterized by two dorsal fins, the second of which is larger than the first and has a venomous spine. This species is found in both the Atlantic and Pacific Oceans and can grow up to about three feet in length. The smooth dogfish, on the other hand, lacks spines on its dorsal fins and is found primarily in warmer waters along the coasts of North and South America.

While not a medical term, it's worth noting that some species of dogfish are used in medical research and have contributed to our understanding of various physiological processes. For example, the electric organs of certain types of dogfish have been studied for their potential applications in nerve impulse transmission and muscle contraction.

Alligators and crocodiles are large, semi-aquatic reptiles belonging to the order Crocodylia. They are characterized by a long, broad snout, powerful tail, and sharp teeth designed for grabbing and holding onto prey. Alligators and crocodiles are similar in appearance but can be distinguished by their snouts: alligators have a wider, U-shaped snout, while crocodiles have a more V-shaped snout.

Alligators (family Alligatoridae) are native to the United States and China, with two living species: the American alligator (Alligator mississippiensis) and the Chinese alligator (Alligator sinensis). They prefer freshwater habitats such as rivers, lakes, and marshes.

Crocodiles (family Crocodylidae) are found in tropical regions around the world, including Africa, Asia, Australia, and the Americas. There are 14 species of crocodiles, including the Nile crocodile (Crocodylus niloticus), the Saltwater crocodile (Crocodylus porosus), and the American crocodile (Crocodylus acutus). Crocodiles can tolerate both freshwater and saltwater environments.

Both alligators and crocodiles are apex predators, feeding on a variety of animals such as fish, birds, and mammals. They are known for their powerful bite force and have been reported to take down large prey, including deer and cattle. Alligators and crocodiles play an important role in maintaining the balance of their ecosystems by controlling populations of other animals and helping to keep waterways clean.

While alligators and crocodiles are often feared due to their size and predatory nature, they are also threatened by habitat loss, pollution, and hunting. Several species are considered endangered or vulnerable, and conservation efforts are underway to protect them and their habitats.

Organogenesis is the process of formation and development of organs during embryonic growth. It involves the complex interactions of cells, tissues, and signaling molecules that lead to the creation of specialized structures in the body. This process begins in the early stages of embryonic development, around week 4-8, and continues until birth. During organogenesis, the three primary germ layers (ectoderm, mesoderm, and endoderm) differentiate into various cell types and organize themselves into specific structures that will eventually form the functional organs of the body. Abnormalities in organogenesis can result in congenital disorders or birth defects.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Trans-activators are proteins that increase the transcriptional activity of a gene or a set of genes. They do this by binding to specific DNA sequences and interacting with the transcription machinery, thereby enhancing the recruitment and assembly of the complexes needed for transcription. In some cases, trans-activators can also modulate the chromatin structure to make the template more accessible to the transcription machinery.

In the context of HIV (Human Immunodeficiency Virus) infection, the term "trans-activator" is often used specifically to refer to the Tat protein. The Tat protein is a viral regulatory protein that plays a critical role in the replication of HIV by activating the transcription of the viral genome. It does this by binding to a specific RNA structure called the Trans-Activation Response Element (TAR) located at the 5' end of all nascent HIV transcripts, and recruiting cellular cofactors that enhance the processivity and efficiency of RNA polymerase II, leading to increased viral gene expression.

Fibroblast Growth Factors (FGFs) are a family of growth factors that play crucial roles in various biological processes, including cell survival, proliferation, migration, and differentiation. They bind to specific tyrosine kinase receptors (FGFRs) on the cell surface, leading to intracellular signaling cascades that regulate gene expression and downstream cellular responses. FGFs are involved in embryonic development, tissue repair, and angiogenesis (the formation of new blood vessels). There are at least 22 distinct FGFs identified in humans, each with unique functions and patterns of expression. Some FGFs, like FGF1 and FGF2, have mitogenic effects on fibroblasts and other cell types, while others, such as FGF7 and FGF10, are essential for epithelial-mesenchymal interactions during organ development. Dysregulation of FGF signaling has been implicated in various pathological conditions, including cancer, fibrosis, and developmental disorders.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

A nodal protein, in the context of molecular biology and genetics, refers to a protein that plays a role in signal transmission within a cell at a node or junction point of a signaling pathway. These proteins are often involved in regulatory processes, such as activating or inhibiting downstream effectors in response to specific signals received by the cell. Nodal proteins can be activated or deactivated through various mechanisms, including phosphorylation, ubiquitination, and interactions with other signaling molecules.

In a more specific context, nodal proteins are also known as nodal factors, which are members of the transforming growth factor-beta (TGF-β) superfamily of signaling molecules that play critical roles in embryonic development and tissue homeostasis. Nodal is a secreted protein that acts as a morphogen, inducing different cellular responses depending on its concentration gradient. It is involved in establishing left-right asymmetry during embryonic development and regulates various processes such as cell proliferation, differentiation, and apoptosis.

In summary, nodal proteins can refer to any protein that functions at a node or junction point of a signaling pathway, but they are also specifically known as nodal factors, which are TGF-β superfamily members involved in embryonic development and tissue homeostasis.

Introns are non-coding sequences of DNA that are present within the genes of eukaryotic organisms, including plants, animals, and humans. Introns are removed during the process of RNA splicing, in which the initial RNA transcript is cut and reconnected to form a mature, functional RNA molecule.

After the intron sequences are removed, the remaining coding sequences, known as exons, are joined together to create a continuous stretch of genetic information that can be translated into a protein or used to produce non-coding RNAs with specific functions. The removal of introns allows for greater flexibility in gene expression and regulation, enabling the generation of multiple proteins from a single gene through alternative splicing.

In summary, introns are non-coding DNA sequences within genes that are removed during RNA processing to create functional RNA molecules or proteins.

Gastrulation is a fundamental process in embryonic development, characterized by the transformation of a initially flat layer of cells called the blastula into a three-layered structure known as the gastrula. This complex series of cellular movements and rearrangements establishes the foundation for the formation of the three primary germ layers: the ectoderm, mesoderm, and endoderm. These germ layers further differentiate to give rise to all the diverse cell types and tissues in the developing organism, including the nervous system, muscles, bones, and internal organs.

The precise mechanisms of gastrulation vary among different animal groups; however, common features include:

1. Formation of a blastopore: A small indentation or opening that forms on the surface of the blastula, which eventually develops into the primitive gut or anus in the gastrula.
2. Invagination: The process by which cells at the blastopore fold inward and migrate towards the interior of the embryo, forming the endodermal layer.
3. Epiboly: A coordinated movement of cells that spreads over and encloses the yolk within the embryo, contributing to the formation of the ectodermal layer.
4. Delamination: The separation and migration of cells from the epiblast (the outer layer of the blastula) to form the mesodermal layer in between the ectoderm and endoderm.

Gastrulation is a critical period in embryonic development, as errors during this process can lead to severe congenital abnormalities or even embryonic lethality. A thorough understanding of gastrulation has important implications for regenerative medicine, stem cell research, and the study of evolutionary developmental biology (Evo-Devo).

Repressor proteins are a type of regulatory protein in molecular biology that suppress the transcription of specific genes into messenger RNA (mRNA) by binding to DNA. They function as part of gene regulation processes, often working in conjunction with an operator region and a promoter region within the DNA molecule. Repressor proteins can be activated or deactivated by various signals, allowing for precise control over gene expression in response to changing cellular conditions.

There are two main types of repressor proteins:

1. DNA-binding repressors: These directly bind to specific DNA sequences (operator regions) near the target gene and prevent RNA polymerase from transcribing the gene into mRNA.
2. Allosteric repressors: These bind to effector molecules, which then cause a conformational change in the repressor protein, enabling it to bind to DNA and inhibit transcription.

Repressor proteins play crucial roles in various biological processes, such as development, metabolism, and stress response, by controlling gene expression patterns in cells.

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

Salamandridae is not a medical term, but a taxonomic designation in the field of biology. It refers to a family of amphibians commonly known as newts and salamanders. These creatures are characterized by their slender bodies, moist skin, and four legs. Some species have the ability to regenerate lost body parts, including limbs, spinal cord, heart, and more.

If you're looking for a medical term, please provide more context or check if you may have made a typo in your question.

The Neural Tube is a structure that forms during the development of an embryo and eventually becomes the brain, spinal cord, and other parts of the nervous system. It is a narrow channel that runs along the back of the embryo, forming from the ectoderm (one of the three germ layers) and closing around the 23rd or 26th day after conception. Defects in the closure of the neural tube can lead to conditions such as spina bifida and anencephaly.

I cannot provide a medical definition for "carps" as it is not a term used in medicine. The term "carp" refers to a type of freshwater fish that belongs to the family Cyprinidae. If you meant to ask about something else, please provide more context or clarify your question.

Oncorhynchus mykiss is the scientific name for a species of fish that is commonly known as the Rainbow Trout. According to the medical or clinical definition provided by the US National Library of Medicine, Oncorhynchus mykiss is "a freshwater fish that is widely cultured and an important food source in many parts of the world." It is also a popular game fish and is often stocked in lakes and rivers for recreational fishing. Rainbow trout are native to cold-water tributaries that flow into the Pacific Ocean in Asia and North America. They have been introduced widely throughout the world and can now be found in freshwater systems on every continent except Antarctica. Rainbow trout are a valuable species for both commercial and recreational fisheries, and they also play an important role in the food web as both predators and prey.

Notch receptors are a type of transmembrane receptor proteins that play crucial roles in cell-cell communication and regulation of various biological processes, including cell fate determination, differentiation, proliferation, and apoptosis. These receptors are highly conserved across species and are essential for normal development and tissue homeostasis.

The Notch signaling pathway is initiated when the extracellular domain of a Notch receptor on one cell interacts with its ligand (such as Delta or Jagged) on an adjacent cell. This interaction triggers a series of proteolytic cleavage events that release the intracellular domain of the Notch receptor, which then translocates to the nucleus and regulates gene expression by interacting with transcription factors like CSL (CBF1/RBP-Jκ/Su(H)/Lag-1).

There are four known Notch receptors in humans (Notch1-4) that share a similar structure, consisting of an extracellular domain containing multiple epidermal growth factor (EGF)-like repeats, a transmembrane domain, and an intracellular domain. Mutations or dysregulation of the Notch signaling pathway have been implicated in various human diseases, including cancer, cardiovascular disorders, and developmental abnormalities.

Cilia are tiny, hair-like structures that protrude from the surface of many types of cells in the body. They are composed of a core bundle of microtubules surrounded by a protein matrix and are covered with a membrane. Cilia are involved in various cellular functions, including movement of fluid or mucus across the cell surface, detection of external stimuli, and regulation of signaling pathways.

There are two types of cilia: motile and non-motile. Motile cilia are able to move in a coordinated manner to propel fluids or particles across a surface, such as those found in the respiratory tract and reproductive organs. Non-motile cilia, also known as primary cilia, are present on most cells in the body and serve as sensory organelles that detect chemical and mechanical signals from the environment.

Defects in cilia structure or function can lead to a variety of diseases, collectively known as ciliopathies. These conditions can affect multiple organs and systems in the body, including the brain, kidneys, liver, and eyes. Examples of ciliopathies include polycystic kidney disease, Bardet-Biedl syndrome, and Meckel-Gruber syndrome.

Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

I apologize for any confusion, but "insects" are not a medical term. Insects are small air-breathing arthropods that have a segmented body with six legs and usually have wings. They make up the largest group of animals on Earth, with over a million described species.

If you're looking for information about a specific medical condition or topic, please provide more details so I can offer a relevant response.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

OTX (Orthodenticle homeobox) transcription factors are a family of proteins that regulate gene expression during embryonic development, particularly in the eye, forebrain, and midbrain. They play crucial roles in the development and differentiation of these tissues, including the specification of eye field identity, the determination of dorsoventral patterning in the neural tube, and the regulation of neurogenesis.

OTX transcription factors contain a highly conserved DNA-binding domain called the homeodomain, which allows them to recognize and bind to specific DNA sequences. In humans, there are four known OTX transcription factors (OTX1, OTX2, OTX3, and CRX), each with distinct expression patterns and functions.

Mutations in OTX genes have been associated with various developmental disorders, such as microphthalmia, anophthalmia, and severe eye malformations, highlighting their importance in normal eye development. Additionally, OTX transcription factors have also been implicated in the pathogenesis of certain cancers, including medulloblastoma and retinoblastoma.

Genomics is the scientific study of genes and their functions. It involves the sequencing and analysis of an organism's genome, which is its complete set of DNA, including all of its genes. Genomics also includes the study of how genes interact with each other and with the environment. This field of study can provide important insights into the genetic basis of diseases and can lead to the development of new diagnostic tools and treatments.

The branchial region, also known as the pharyngeal region or viscerocranium, is a term used in human anatomy to refer to the area of the developing embryo that gives rise to structures derived from the branchial (or pharyngeal) arches. The branchial arches are a series of paired, rod-like structures that appear early in embryonic development and give rise to various head and neck structures, including the bones and muscles of the face, jaws, and neck, as well as the associated nerves, blood vessels, and connective tissues.

The branchial region is divided into several subregions, each corresponding to a specific branchial arch. The first branchial arch gives rise to structures such as the mandible (lower jaw), maxilla (upper jaw), and muscles of mastication (chewing). The second branchial arch forms the stapes and styloid process in the ear, as well as some neck muscles. The third and fourth branchial arches contribute to the formation of the larynx, thyroid cartilage, and other structures in the neck.

Abnormalities in the development of the branchial region can lead to a variety of congenital defects, such as cleft palate, micrognathia (small jaw), and branchial cysts or sinuses. These conditions may require surgical intervention to correct.

Tissue distribution, in the context of pharmacology and toxicology, refers to the way that a drug or xenobiotic (a chemical substance found within an organism that is not naturally produced by or expected to be present within that organism) is distributed throughout the body's tissues after administration. It describes how much of the drug or xenobiotic can be found in various tissues and organs, and is influenced by factors such as blood flow, lipid solubility, protein binding, and the permeability of cell membranes. Understanding tissue distribution is important for predicting the potential effects of a drug or toxin on different parts of the body, and for designing drugs with improved safety and efficacy profiles.

Ambystoma mexicanum is the scientific name for the axolotl, a type of salamander that is native to Mexico. The axolotl is also known as the Mexican walking fish, although it is not actually a fish but an amphibian. It is unique because it exhibits neoteny, which means it can remain in its larval form throughout its entire life and never undergo complete metamorphosis into a terrestrial form.

The axolotl is a popular organism in scientific research due to its ability to regenerate lost body parts, including limbs, spinal cord, heart, and other organs. This has made it an important model organism for studying the mechanisms of regeneration and repair in mammals, including humans.

Fibroblast Growth Factor 8 (FGF-8) is a growth factor that belongs to the fibroblast growth factor family. It plays crucial roles in various biological processes, including embryonic development, tissue repair, and cancer progression. Specifically, FGF-8 has been implicated in the regulation of cell proliferation, differentiation, migration, and survival.

During embryonic development, FGF-8 is involved in the formation of the nervous system, limbs, and other organs. It acts as a signaling molecule that helps to establish patterns of gene expression and cell behavior during development. In tissue repair, FGF-8 can stimulate the proliferation and migration of cells involved in wound healing, such as fibroblasts and endothelial cells.

In cancer, FGF-8 has been shown to promote tumor growth, angiogenesis (the formation of new blood vessels), and metastasis. It can do this by activating signaling pathways that promote cell proliferation, survival, and migration. Overexpression of FGF-8 has been found in various types of cancer, including breast, lung, prostate, and ovarian cancer.

In summary, Fibroblast Growth Factor 8 (FGF-8) is a signaling molecule that plays important roles in embryonic development, tissue repair, and cancer progression by regulating cell proliferation, differentiation, migration, and survival.

Arthropods are a phylum of animals characterized by the presence of a segmented body, a pair of jointed appendages on each segment, and a tough exoskeleton made of chitin. This phylum includes insects, arachnids (spiders, scorpions, mites), crustaceans (crabs, lobsters, shrimp), and myriapods (centipedes, millipedes). They are the largest group of animals on Earth, making up more than 80% of all described species. Arthropods can be found in nearly every habitat, from the deep sea to mountaintops, and play important roles in ecosystems as decomposers, pollinators, and predators.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Protein isoforms are different forms or variants of a protein that are produced from a single gene through the process of alternative splicing, where different exons (or parts of exons) are included in the mature mRNA molecule. This results in the production of multiple, slightly different proteins that share a common core structure but have distinct sequences and functions. Protein isoforms can also arise from genetic variations such as single nucleotide polymorphisms or mutations that alter the protein-coding sequence of a gene. These differences in protein sequence can affect the stability, localization, activity, or interaction partners of the protein isoform, leading to functional diversity and specialization within cells and organisms.

I'm sorry for any confusion, but "snakes" is not a medical term. It refers to a group of legless reptiles that can be found on every continent except Antarctica. If you have any questions about snakes in a different context, please provide more information and I'll do my best to help!

Genes in insects refer to the hereditary units of DNA that are passed down from parents to offspring and contain the instructions for the development, function, and reproduction of an organism. These genetic materials are located within the chromosomes in the nucleus of insect cells. They play a crucial role in determining various traits such as physical characteristics, behavior, and susceptibility to diseases.

Insect genes, like those of other organisms, consist of exons (coding regions) that contain information for protein synthesis and introns (non-coding regions) that are removed during the process of gene expression. The expression of insect genes is regulated by various factors such as transcription factors, enhancers, and silencers, which bind to specific DNA sequences to activate or repress gene transcription.

Understanding the genetic makeup of insects has important implications for various fields, including agriculture, public health, and evolutionary biology. For example, genes associated with insect pests' resistance to pesticides can be identified and targeted to develop more effective control strategies. Similarly, genes involved in disease transmission by insect vectors such as mosquitoes can be studied to develop novel interventions for preventing the spread of infectious diseases.

Organ specificity, in the context of immunology and toxicology, refers to the phenomenon where a substance (such as a drug or toxin) or an immune response primarily affects certain organs or tissues in the body. This can occur due to various reasons such as:

1. The presence of specific targets (like antigens in the case of an immune response or receptors in the case of drugs) that are more abundant in these organs.
2. The unique properties of certain cells or tissues that make them more susceptible to damage.
3. The way a substance is metabolized or cleared from the body, which can concentrate it in specific organs.

For example, in autoimmune diseases, organ specificity describes immune responses that are directed against antigens found only in certain organs, such as the thyroid gland in Hashimoto's disease. Similarly, some toxins or drugs may have a particular affinity for liver cells, leading to liver damage or specific drug interactions.

I believe there may be some confusion in your question. "Quail" is typically used to refer to a group of small birds that belong to the family Phasianidae and the subfamily Perdicinae. There is no established medical definition for "quail."

However, if you're referring to the verb "to quail," it means to shrink back, draw back, or cower, often due to fear or intimidation. In a medical context, this term could be used metaphorically to describe a patient's psychological response to a threatening situation, such as receiving a difficult diagnosis. But again, "quail" itself is not a medical term.

'Caenorhabditis elegans' (C. elegans) is a type of free-living, transparent nematode (roundworm) that is often used as a model organism in scientific research. C. elegans proteins refer to the various types of protein molecules that are produced by the organism's genes and play crucial roles in maintaining its biological functions.

Proteins are complex molecules made up of long chains of amino acids, and they are involved in virtually every cellular process, including metabolism, DNA replication, signal transduction, and transportation of molecules within the cell. In C. elegans, proteins are encoded by genes, which are transcribed into messenger RNA (mRNA) molecules that are then translated into protein sequences by ribosomes.

Studying C. elegans proteins is important for understanding the basic biology of this organism and can provide insights into more complex biological systems, including humans. Because C. elegans has a relatively simple nervous system and a short lifespan, it is often used to study neurobiology, aging, and development. Additionally, because many of the genes and proteins in C. elegans have counterparts in other organisms, including humans, studying them can provide insights into human disease processes and potential therapeutic targets.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

Endoderm is the innermost of the three primary germ layers in a developing embryo, along with the ectoderm and mesoderm. The endoderm gives rise to several internal tissues and organs, most notably those found in the digestive system and respiratory system. Specifically, it forms the lining of the gut tube, which eventually becomes the epithelial lining of the gastrointestinal tract, liver, pancreas, lungs, and other associated structures.

During embryonic development, the endoderm arises from the inner cell mass of the blastocyst, following a series of cell divisions and migrations that help to establish the basic body plan of the organism. As the embryo grows and develops, the endoderm continues to differentiate into more specialized tissues and structures, playing a critical role in the formation of many essential bodily functions.

A mammalian embryo is the developing offspring of a mammal, from the time of implantation of the fertilized egg (blastocyst) in the uterus until the end of the eighth week of gestation. During this period, the embryo undergoes rapid cell division and organ differentiation to form a complex structure with all the major organs and systems in place. This stage is followed by fetal development, which continues until birth. The study of mammalian embryos is important for understanding human development, evolution, and reproductive biology.

Dinosaurs are a group of reptiles that were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous period. They first appeared approximately 230 million years ago and went extinct around 65 million years ago.

Dinosaurs are characterized by their upright stance, with legs positioned directly under their bodies, and a wide range of body sizes and shapes. Some dinosaurs were enormous, such as the long-necked sauropods that could reach lengths of over 100 feet, while others were small and agile.

Dinosaurs are classified into two main groups: the saurischians (lizard-hipped) and the ornithischians (bird-hipped). The saurischians include both the large carnivorous theropods, such as Tyrannosaurus rex, and the long-necked sauropods. The ornithischians were primarily herbivores and included a diverse array of species, such as the armored ankylosaurs and the horned ceratopsians.

Despite their extinction, dinosaurs have left a lasting impact on our planet and continue to be a source of fascination for people of all ages. The study of dinosaurs, known as paleontology, has shed light on many aspects of Earth's history and the evolution of life on our planet.

'Cell lineage' is a term used in biology and medicine to describe the developmental history or relationship of a cell or group of cells to other cells, tracing back to the original progenitor or stem cell. It refers to the series of cell divisions and differentiation events that give rise to specific types of cells in an organism over time.

In simpler terms, cell lineage is like a family tree for cells, showing how they are related to each other through a chain of cell division and specialization events. This concept is important in understanding the development, growth, and maintenance of tissues and organs in living beings.

Bufonidae is a family of toads, characterized by the presence of parotoid glands that produce bufotoxins, a group of toxic secretions. These toads are found worldwide, except for Australia, New Zealand, Madagascar, and some isolated islands. They vary in size, shape, and coloration, depending on the species. Some notable members of this family include the common toad (Bufo bufo) and the Colorado River toad (Incilius alvarius). It is important to note that while these toads have toxic secretions, they are not typically harmful to humans unless ingested or if their secretions come into contact with mucous membranes or broken skin.

Light signal transduction is a biological process that refers to the way in which cells convert light signals into chemical or electrical responses. This process typically involves several components, including a light-sensitive receptor (such as a photopigment), a signaling molecule (like a G-protein or calcium ion), and an effector protein that triggers a downstream response.

In the visual system, for example, light enters the eye and activates photoreceptor cells in the retina. These cells contain a light-sensitive pigment called rhodopsin, which undergoes a chemical change when struck by a photon of light. This change triggers a cascade of signaling events that ultimately lead to the transmission of visual information to the brain.

Light signal transduction is also involved in other biological processes, such as the regulation of circadian rhythms and the synthesis of vitamin D. In these cases, specialized cells contain light-sensitive receptors that allow them to detect changes in ambient light levels and adjust their physiology accordingly.

Overall, light signal transduction is a critical mechanism by which organisms are able to sense and respond to their environment.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

T-box domain proteins are a family of transcription factors that share a highly conserved DNA-binding domain, known as the T-box. The T-box domain is a DNA-binding motif that specifically recognizes and binds to T-box binding elements (TBEs) in the regulatory regions of target genes. These proteins play crucial roles during embryonic development, particularly in the formation of specific tissues and organs, such as the heart, limbs, and brain. Mutations in T-box domain proteins can lead to various congenital defects and developmental disorders. Some examples of T-box domain proteins include TBX1, TBX5, and TBX20.

I believe there might be a slight misunderstanding in your question. In genetics, there are no specific "gene components." However, genes themselves are made up of DNA (deoxyribonucleic acid) molecules, which consist of two complementary strands that twist around each other to form a double helix.

The DNA molecule is composed of four nucleotide bases - adenine (A), thymine (T), guanine (G), and cytosine (C). These bases pair up with each other in specific ways: Adenine with thymine, and guanine with cytosine.

The gene is a segment of DNA that contains the instructions for making a particular protein or performing a specific function within an organism. The sequence of these nucleotide bases determines the genetic information encoded in a gene.

So, if you're referring to the parts of a gene, they can be described as:

1. Promoter: A region at the beginning of a gene that acts as a binding site for RNA polymerase, an enzyme responsible for transcribing DNA into RNA.
2. Introns and exons: Introns are non-coding sequences within a gene, while exons are coding sequences that contain information for protein synthesis. Introns are removed during RNA processing, and exons are spliced together to form the final mature mRNA (messenger RNA) molecule.
3. Regulatory elements: These are specific DNA sequences that control gene expression, such as enhancers, silencers, and transcription factor binding sites. They can be located upstream, downstream, or even within introns of a gene.
4. Terminator: A region at the end of a gene that signals RNA polymerase to stop transcribing DNA into RNA.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Morpholinos are synthetic oligonucleotides that contain morpholine rings in their backbone instead of the ribose or deoxyribose sugars found in DNA and RNA. They are often used as antisense agents to inhibit gene expression by binding to complementary RNA sequences, preventing translation or splicing. Morpholinos are resistant to nucleases and have a neutral charge, which makes them more stable and less likely to cause off-target effects compared to other antisense technologies. They have been widely used in research to study gene function and have also shown promise as therapeutic agents for various diseases, including neuromuscular disorders and viral infections.

In the context of human anatomy, the term "tail" is not used to describe any part of the body. Humans are considered tailless primates, and there is no structure or feature that corresponds directly to the tails found in many other animals.

However, there are some medical terms related to the lower end of the spine that might be confused with a tail:

1. Coccyx (Tailbone): The coccyx is a small triangular bone at the very bottom of the spinal column, formed by the fusion of several rudimentary vertebrae. It's also known as the tailbone because it resembles the end of an animal's tail in its location and appearance.
2. Cauda Equina (Horse's Tail): The cauda equina is a bundle of nerve roots at the lower end of the spinal cord, just above the coccyx. It got its name because it looks like a horse's tail due to the numerous rootlets radiating from the conus medullaris (the tapering end of the spinal cord).

These two structures are not tails in the traditional sense but rather medical terms related to the lower end of the human spine.

A skeleton is not a medical condition or term, but rather an anatomical structure. Medically, the skeletal system refers to the body's organic framework that provides support and shape to the body, protects vital organs, and enables motion through attachment to muscles. The human skeleton is made up of 206 bones in an adult, which are categorized into axial (80 bones) and appendicular (126 bones) skeletons.

The axial skeleton forms the central axis of the body and consists of the skull, vertebral column, sternum, and ribcage. The appendicular skeleton includes the upper and lower extremities (limbs), shoulder girdle, and pelvic girdle.

In summary, a skeleton is the collective term for all bones in an organism's body that provide structure, support, protection, and mobility.

Gills are specialized respiratory organs found in many aquatic organisms such as fish, crustaceans, and some mollusks. They are typically thin, feathery structures that increase the surface area for gas exchange between the water and the animal's bloodstream. Gills extract oxygen from water while simultaneously expelling carbon dioxide.

In fish, gills are located in the gill chamber, which is covered by opercula or protective bony flaps. Water enters through the mouth, flows over the gills, and exits through the opercular openings. The movement of water over the gills allows for the diffusion of oxygen and carbon dioxide across the gill filaments and lamellae, which are the thin plates where gas exchange occurs.

Gills contain a rich supply of blood vessels, allowing for efficient transport of oxygen to the body's tissues and removal of carbon dioxide. The counter-current flow of water and blood in the gills ensures that the concentration gradient between the water and the blood is maximized, enhancing the efficiency of gas exchange.

The inner ear is the innermost part of the ear that contains the sensory organs for hearing and balance. It consists of a complex system of fluid-filled tubes and sacs called the vestibular system, which is responsible for maintaining balance and spatial orientation, and the cochlea, a spiral-shaped organ that converts sound vibrations into electrical signals that are sent to the brain.

The inner ear is located deep within the temporal bone of the skull and is protected by a bony labyrinth. The vestibular system includes the semicircular canals, which detect rotational movements of the head, and the otolith organs (the saccule and utricle), which detect linear acceleration and gravity.

Damage to the inner ear can result in hearing loss, tinnitus (ringing in the ears), vertigo (a spinning sensation), and balance problems.

Echinodermata is a phylum in the animal kingdom that includes various marine organisms such as sea stars, sea urchins, sand dollars, brittle stars, and sea cucumbers. The name Echinodermata comes from the Greek words "echinos," meaning spiny, and "derma," meaning skin, which refers to the characteristic spiny skin of many echinoderms.

Echinoderms are bilaterally symmetrical as larvae but become radially symmetrical as adults, with their bodies organized around a central axis. They have a unique water vascular system that helps them move and respire, and most species have specialized structures called pedicellariae that help them clean and defend themselves.

Echinoderms are also known for their ability to regenerate lost body parts, and some species can even undergo asexual reproduction through fragmentation. They play important ecological roles in marine ecosystems, including grazing on algae and other organisms, breaking down organic matter, and serving as prey for larger animals.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Biological metamorphosis is a complex process of transformation that certain organisms undergo during their development from embryo to adult. This process involves profound changes in form, function, and structure of the organism, often including modifications of various body parts, reorganization of internal organs, and changes in physiology.

In metamorphosis, a larval or juvenile form of an animal is significantly different from its adult form, both morphologically and behaviorally. This phenomenon is particularly common in insects, amphibians, and some fish and crustaceans. The most well-known examples include the transformation of a caterpillar into a butterfly or a tadpole into a frog.

The mechanisms that drive metamorphosis are regulated by hormonal signals and genetic programs. In many cases, metamorphosis is triggered by environmental factors such as temperature, moisture, or food availability, which interact with the organism's internal developmental cues to initiate the transformation. The process of metamorphosis allows these organisms to exploit different ecological niches at different stages of their lives and contributes to their evolutionary success.

I'm sorry for any confusion, but "Perciformes" is not a medical term. It is a term used in the field of biology, specifically in taxonomy and ichthyology (the study of fish). Perciformes is an order of ray-finned bony fishes that includes over 10,000 species, making it the largest order of vertebrates. Examples of fish within this order include perch, sea bass, sunfish, and tuna.

Chromosome mapping, also known as physical mapping, is the process of determining the location and order of specific genes or genetic markers on a chromosome. This is typically done by using various laboratory techniques to identify landmarks along the chromosome, such as restriction enzyme cutting sites or patterns of DNA sequence repeats. The resulting map provides important information about the organization and structure of the genome, and can be used for a variety of purposes, including identifying the location of genes associated with genetic diseases, studying evolutionary relationships between organisms, and developing genetic markers for use in breeding or forensic applications.

The prosencephalon is a term used in the field of neuroembryology, which refers to the developmental stage of the forebrain in the embryonic nervous system. It is one of the three primary vesicles that form during the initial stages of neurulation, along with the mesencephalon (midbrain) and rhombencephalon (hindbrain).

The prosencephalon further differentiates into two secondary vesicles: the telencephalon and diencephalon. The telencephalon gives rise to structures such as the cerebral cortex, basal ganglia, and olfactory bulbs, while the diencephalon develops into structures like the thalamus, hypothalamus, and epithalamus.

It is important to note that 'prosencephalon' itself is not used as a medical term in adult neuroanatomy, but it is crucial for understanding the development of the human brain during embryogenesis.

A "gene library" is not a recognized term in medical genetics or molecular biology. However, the closest concept that might be referred to by this term is a "genomic library," which is a collection of DNA clones that represent the entire genetic material of an organism. These libraries are used for various research purposes, such as identifying and studying specific genes or gene functions.

An axon is a long, slender extension of a neuron (a type of nerve cell) that conducts electrical impulses (nerve impulses) away from the cell body to target cells, such as other neurons or muscle cells. Axons can vary in length from a few micrometers to over a meter long and are typically surrounded by a myelin sheath, which helps to insulate and protect the axon and allows for faster transmission of nerve impulses.

Axons play a critical role in the functioning of the nervous system, as they provide the means by which neurons communicate with one another and with other cells in the body. Damage to axons can result in serious neurological problems, such as those seen in spinal cord injuries or neurodegenerative diseases like multiple sclerosis.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Ocular vision refers to the ability to process and interpret visual information that is received by the eyes. This includes the ability to see clearly and make sense of the shapes, colors, and movements of objects in the environment. The ocular system, which includes the eye and related structures such as the optic nerve and visual cortex of the brain, works together to enable vision.

There are several components of ocular vision, including:

* Visual acuity: the clarity or sharpness of vision
* Field of vision: the extent of the visual world that is visible at any given moment
* Color vision: the ability to distinguish different colors
* Depth perception: the ability to judge the distance of objects in three-dimensional space
* Contrast sensitivity: the ability to distinguish an object from its background based on differences in contrast

Disorders of ocular vision can include refractive errors such as nearsightedness or farsightedness, as well as more serious conditions such as cataracts, glaucoma, and macular degeneration. These conditions can affect one or more aspects of ocular vision and may require medical treatment to prevent further vision loss.

Mollusca is not a medical term per se, but a major group of invertebrate animals that includes snails, clams, octopuses, and squids. However, medically, some mollusks can be relevant as they can act as vectors for various diseases, such as schistosomiasis (transmitted by freshwater snails) and fascioliasis (transmitted by aquatic snails). Therefore, a medical definition might describe Mollusca as a phylum of mostly marine invertebrates that can sometimes play a role in the transmission of certain infectious diseases.

Sequence homology is a term used in molecular biology to describe the similarity between the nucleotide or amino acid sequences of two or more genes or proteins. It is a measure of the degree to which the sequences are related, indicating a common evolutionary origin.

In other words, sequence homology implies that the compared sequences have a significant number of identical or similar residues in the same order, suggesting that they share a common ancestor and have diverged over time through processes such as mutation, insertion, deletion, or rearrangement. The higher the degree of sequence homology, the more closely related the sequences are likely to be.

Sequence homology is often used to identify similarities between genes or proteins from different species, which can provide valuable insights into their functions, structures, and evolutionary relationships. It is commonly assessed using various bioinformatics tools and algorithms, such as BLAST (Basic Local Alignment Search Tool), Clustal Omega, and multiple sequence alignment (MSA) methods.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

Photoreceptor cells are specialized neurons in the retina of the eye that convert light into electrical signals. These cells consist of two types: rods and cones. Rods are responsible for vision at low light levels and provide black-and-white, peripheral, and motion sensitivity. Cones are active at higher light levels and are capable of color discrimination and fine detail vision. Both types of photoreceptor cells contain light-sensitive pigments that undergo chemical changes when exposed to light, triggering a series of electrical signals that ultimately reach the brain and contribute to visual perception.

Green Fluorescent Protein (GFP) is not a medical term per se, but a scientific term used in the field of molecular biology. GFP is a protein that exhibits bright green fluorescence when exposed to light, particularly blue or ultraviolet light. It was originally discovered in the jellyfish Aequorea victoria.

In medical and biological research, scientists often use recombinant DNA technology to introduce the gene for GFP into other organisms, including bacteria, plants, and animals, including humans. This allows them to track the expression and localization of specific genes or proteins of interest in living cells, tissues, or even whole organisms.

The ability to visualize specific cellular structures or processes in real-time has proven invaluable for a wide range of research areas, from studying the development and function of organs and organ systems to understanding the mechanisms of diseases and the effects of therapeutic interventions.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

Retinal rod photoreceptor cells are specialized neurons in the retina of the eye that are primarily responsible for vision in low light conditions. They contain a light-sensitive pigment called rhodopsin, which undergoes a chemical change when struck by a single photon of light. This triggers a cascade of biochemical reactions that ultimately leads to the generation of electrical signals, which are then transmitted to the brain via the optic nerve.

Rod cells do not provide color vision or fine detail, but they allow us to detect motion and see in dim light. They are more sensitive to light than cone cells, which are responsible for color vision and detailed sight in bright light conditions. Rod cells are concentrated at the outer edges of the retina, forming a crescent-shaped region called the peripheral retina, with fewer rod cells located in the central region of the retina known as the fovea.

"Ambystoma" is a genus of salamanders, also known as the mole salamanders. These amphibians are characterized by their fossorial (burrowing) habits and typically have four limbs, a tail, and moist skin. They are found primarily in North America, with a few species in Asia and Europe. Some well-known members of this genus include the axolotl (A. mexicanum), which is famous for its ability to regenerate lost body parts, and the spotted salamander (A. maculatum). The name "Ambystoma" comes from the Greek words "amblys," meaning blunt, and "stoma," meaning mouth, in reference to the wide, blunt snout of these animals.

Alternative splicing is a process in molecular biology that occurs during the post-transcriptional modification of pre-messenger RNA (pre-mRNA) molecules. It involves the removal of non-coding sequences, known as introns, and the joining together of coding sequences, or exons, to form a mature messenger RNA (mRNA) molecule that can be translated into a protein.

In alternative splicing, different combinations of exons are selected and joined together to create multiple distinct mRNA transcripts from a single pre-mRNA template. This process increases the diversity of proteins that can be produced from a limited number of genes, allowing for greater functional complexity in organisms.

Alternative splicing is regulated by various cis-acting elements and trans-acting factors that bind to specific sequences in the pre-mRNA molecule and influence which exons are included or excluded during splicing. Abnormal alternative splicing has been implicated in several human diseases, including cancer, neurological disorders, and cardiovascular disease.

The skull is the bony structure that encloses and protects the brain, the eyes, and the ears. It is composed of two main parts: the cranium, which contains the brain, and the facial bones. The cranium is made up of several fused flat bones, while the facial bones include the upper jaw (maxilla), lower jaw (mandible), cheekbones, nose bones, and eye sockets (orbits).

The skull also provides attachment points for various muscles that control chewing, moving the head, and facial expressions. Additionally, it contains openings for blood vessels, nerves, and the spinal cord to pass through. The skull's primary function is to protect the delicate and vital structures within it from injury and trauma.

Photoreceptor cells in invertebrates are specialized sensory neurons that convert light stimuli into electrical signals. These cells are primarily responsible for the ability of many invertebrates to detect and respond to light, enabling behaviors such as phototaxis (movement towards or away from light) and vision.

Invertebrate photoreceptor cells typically contain light-sensitive pigments that absorb light at specific wavelengths. The most common type of photopigment is rhodopsin, which consists of a protein called opsin and a chromophore called retinal. When light hits the photopigment, it changes the conformation of the chromophore, triggering a cascade of molecular events that ultimately leads to the generation of an electrical signal.

Invertebrate photoreceptor cells can be found in various locations throughout the body, depending on their function. For example, simple eyespots containing a few photoreceptor cells may be scattered over the surface of the body in some species, while more complex eyes with hundreds or thousands of photoreceptors may be present in other groups. In addition to their role in vision, photoreceptor cells can also serve as sensory organs for regulating circadian rhythms, detecting changes in light intensity, and mediating social behaviors.

The neural plate is a structure formed during the embryonic development of vertebrates. It is a thickened plate of ectodermal cells located on the dorsal surface of the developing embryo. The neural plate gives rise to the central nervous system, including the brain and spinal cord.

The process of neural plate formation begins with the specification of ectodermal cells into neural fated cells, a process that is regulated by various signaling molecules. Once specified, these cells undergo morphological changes, resulting in the thickening of the ectoderm to form the neural plate.

The neural plate then undergoes a series of folding movements, leading to the formation of the neural tube, which eventually develops into the brain and spinal cord. The edges of the neural plate, known as the neural folds, come together and fuse, forming a closed tube. Failure of the neural folds to fuse properly can result in neural tube defects, such as spina bifida.

Overall, the neural plate is a critical structure in the development of the nervous system in vertebrates, and its formation and subsequent development are tightly regulated by various genetic and environmental factors.

Embryonic and fetal development is the process of growth and development that occurs from fertilization of the egg (conception) to birth. The terms "embryo" and "fetus" are used to describe different stages of this development:

* Embryonic development: This stage begins at fertilization and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (zygote) divides and forms a blastocyst, which implants in the uterus and begins to develop into a complex structure called an embryo. The embryo consists of three layers of cells that will eventually form all of the organs and tissues of the body. During this stage, the basic structures of the body, including the nervous system, heart, and gastrointestinal tract, begin to form.
* Fetal development: This stage begins at the end of the 8th week of pregnancy and continues until birth. During this time, the embryo is called a fetus, and it grows and develops rapidly. The organs and tissues that were formed during the embryonic stage continue to mature and become more complex. The fetus also begins to move and kick, and it can hear and respond to sounds from outside the womb.

Overall, embryonic and fetal development is a complex and highly regulated process that involves the coordinated growth and differentiation of cells and tissues. It is a critical period of development that lays the foundation for the health and well-being of the individual throughout their life.

According to the National Institutes of Health (NIH), stem cells are "initial cells" or "precursor cells" that have the ability to differentiate into many different cell types in the body. They can also divide without limit to replenish other cells for as long as the person or animal is still alive.

There are two main types of stem cells: embryonic stem cells, which come from human embryos, and adult stem cells, which are found in various tissues throughout the body. Embryonic stem cells have the ability to differentiate into all cell types in the body, while adult stem cells have more limited differentiation potential.

Stem cells play an essential role in the development and repair of various tissues and organs in the body. They are currently being studied for their potential use in the treatment of a wide range of diseases and conditions, including cancer, diabetes, heart disease, and neurological disorders. However, more research is needed to fully understand the properties and capabilities of these cells before they can be used safely and effectively in clinical settings.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

'Poisonous fishes' are species of fish that contain toxic substances in their bodies, which can cause harm or injury to other organisms, including humans. These toxins can be present in various parts of the fish, such as the flesh, skin, organs, or even in the form of venomous spines.

There are several types of poisonous fishes, including:

1. Pufferfish (Fugu): These fish contain a potent neurotoxin called tetrodotoxin (TTX) in their organs, especially the liver and ovaries. TTX is highly toxic and can cause paralysis and death if ingested in even small amounts.
2. Stonefish: Stonefishes are venomous fishes that have sharp, spiny dorsal fins that can inject a painful toxin into the skin when stepped on or touched. The venom can cause severe pain, swelling, and tissue damage, and in some cases, it can lead to respiratory failure and death.
3. Blue-ringed octopuses: While not technically fish, blue-ringed octopuses are often included in discussions of poisonous marine life. They have venom glands that produce a powerful neurotoxin called tetrodotoxin (TTX), which can cause paralysis and death if it enters the bloodstream.
4. Cone snails: Cone snails are predatory mollusks that use a harpoon-like tooth to inject venom into their prey. Some species of cone snail have venom that contains powerful neurotoxins, which can cause paralysis and death in humans.
5. Lionfish: Lionfish are venomous fishes that have spines on their dorsal, pelvic, and anal fins that can inject a painful toxin into the skin when touched or stepped on. The venom can cause pain, swelling, and other symptoms, but it is rarely fatal to humans.

It's important to note that many species of fish can become toxic if they consume harmful algae blooms (HABs) or other contaminants in their environment. These "toxic fishes" are not considered poisonous by definition, as their toxicity is not inherent to their biology.

Genetic enhancer elements are DNA sequences that increase the transcription of specific genes. They work by binding to regulatory proteins called transcription factors, which in turn recruit RNA polymerase II, the enzyme responsible for transcribing DNA into messenger RNA (mRNA). This results in the activation of gene transcription and increased production of the protein encoded by that gene.

Enhancer elements can be located upstream, downstream, or even within introns of the genes they regulate, and they can act over long distances along the DNA molecule. They are an important mechanism for controlling gene expression in a tissue-specific and developmental stage-specific manner, allowing for the precise regulation of gene activity during embryonic development and throughout adult life.

It's worth noting that genetic enhancer elements are often referred to simply as "enhancers," and they are distinct from other types of regulatory DNA sequences such as promoters, silencers, and insulators.

Expressed Sequence Tags (ESTs) are short, single-pass DNA sequences that are derived from cDNA libraries. They represent a quick and cost-effective method for large-scale sequencing of gene transcripts and provide an unbiased view of the genes being actively expressed in a particular tissue or developmental stage. ESTs can be used to identify and study new genes, to analyze patterns of gene expression, and to develop molecular markers for genetic mapping and genome analysis.

In medical terms, "wing" is not a term that is used as a standalone definition. However, it can be found in the context of certain anatomical structures or medical conditions. For instance, the "wings" of the lungs refer to the upper and lower portions of the lungs that extend from the main body of the organ. Similarly, in dermatology, "winging" is used to describe the spreading out or flaring of the wings of the nose, which can be a characteristic feature of certain skin conditions like lupus.

It's important to note that medical terminology can be highly specific and context-dependent, so it's always best to consult with a healthcare professional for accurate information related to medical definitions or diagnoses.

I'm sorry for any confusion, but "Marsupialia" is not a medical term. It is a taxonomic category in biology, specifically an order that includes mammals known as marsupials. These are mammals that carry their young in a pouch after birth. Examples of marsupials include kangaroos, koalas, and opossums. If you have any medical questions or terms you would like defined, I'd be happy to help!

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Gene expression profiling is a laboratory technique used to measure the activity (expression) of thousands of genes at once. This technique allows researchers and clinicians to identify which genes are turned on or off in a particular cell, tissue, or organism under specific conditions, such as during health, disease, development, or in response to various treatments.

The process typically involves isolating RNA from the cells or tissues of interest, converting it into complementary DNA (cDNA), and then using microarray or high-throughput sequencing technologies to determine which genes are expressed and at what levels. The resulting data can be used to identify patterns of gene expression that are associated with specific biological states or processes, providing valuable insights into the underlying molecular mechanisms of diseases and potential targets for therapeutic intervention.

In recent years, gene expression profiling has become an essential tool in various fields, including cancer research, drug discovery, and personalized medicine, where it is used to identify biomarkers of disease, predict patient outcomes, and guide treatment decisions.

Developmental genes are a set of genes that play crucial roles during the development of an organism, from fertilization to adult form. These genes are responsible for controlling fundamental processes such as cell growth, differentiation, and programmed cell death (apoptosis), which ultimately lead to the formation of various tissues, organs, and body structures. They often encode transcription factors and signaling molecules that regulate complex gene networks and cascades. Some well-known developmental genes are involved in pattern formation, segmentation, and morphogenesis, ensuring the proper spatial organization and function of different parts of the organism. Examples include Hox genes, Wnt genes, and TGF-β genes. Mutations in developmental genes can result in various developmental disorders and congenital abnormalities.

Cell polarity refers to the asymmetric distribution of membrane components, cytoskeleton, and organelles in a cell. This asymmetry is crucial for various cellular functions such as directed transport, cell division, and signal transduction. The plasma membrane of polarized cells exhibits distinct domains with unique protein and lipid compositions that define apical, basal, and lateral surfaces of the cell.

In epithelial cells, for example, the apical surface faces the lumen or external environment, while the basolateral surface interacts with other cells or the extracellular matrix. The establishment and maintenance of cell polarity are regulated by various factors including protein complexes, lipids, and small GTPases. Loss of cell polarity has been implicated in several diseases, including cancer and neurological disorders.

Regeneration in a medical context refers to the process of renewal, restoration, and growth that replaces damaged or missing cells, tissues, organs, or even whole limbs in some organisms. This complex biological process involves various cellular and molecular mechanisms, such as cell proliferation, differentiation, and migration, which work together to restore the structural and functional integrity of the affected area.

In human medicine, regeneration has attracted significant interest due to its potential therapeutic applications in treating various conditions, including degenerative diseases, trauma, and congenital disorders. Researchers are actively studying the underlying mechanisms of regeneration in various model organisms to develop novel strategies for promoting tissue repair and regeneration in humans.

Examples of regeneration in human medicine include liver regeneration after partial hepatectomy, where the remaining liver lobes can grow back to their original size within weeks, and skin wound healing, where keratinocytes migrate and proliferate to close the wound and restore the epidermal layer. However, the regenerative capacity of humans is limited compared to some other organisms, such as planarians and axolotls, which can regenerate entire body parts or even their central nervous system.

Reproduction, in the context of biology and medicine, refers to the process by which organisms produce offspring. It is a complex process that involves the creation, development, and growth of new individuals from parent organisms. In sexual reproduction, this process typically involves the combination of genetic material from two parents through the fusion of gametes (sex cells) such as sperm and egg cells. This results in the formation of a zygote, which then develops into a new individual with a unique genetic makeup.

In contrast, asexual reproduction does not involve the fusion of gametes and can occur through various mechanisms such as budding, fragmentation, or parthenogenesis. Asexual reproduction results in offspring that are genetically identical to the parent organism.

Reproduction is a fundamental process that ensures the survival and continuation of species over time. It is also an area of active research in fields such as reproductive medicine, where scientists and clinicians work to understand and address issues related to human fertility, contraception, and genetic disorders.

Genetic variation refers to the differences in DNA sequences among individuals and populations. These variations can result from mutations, genetic recombination, or gene flow between populations. Genetic variation is essential for evolution by providing the raw material upon which natural selection acts. It can occur within a single gene, between different genes, or at larger scales, such as differences in the number of chromosomes or entire sets of chromosomes. The study of genetic variation is crucial in understanding the genetic basis of diseases and traits, as well as the evolutionary history and relationships among species.

"Rana catesbeiana" is the scientific name for the American bullfrog, which is not a medical term or concept. It belongs to the animal kingdom, specifically in the order Anura and family Ranidae. The American bullfrog is native to North America and is known for its large size and distinctive loud call.

However, if you are looking for a medical definition, I apologize for any confusion. Please provide more context or specify the term you would like me to define.

I'm sorry for any confusion, but "Smegmamorpha" is not a recognized term in medical or scientific fields. It seems like it might be a made-up word, possibly a combination of "smegma," which refers to the secretions found in the genital area, and "-morpha," which is often used in taxonomy to denote a subgroup or form. However, I cannot find any legitimate scientific or medical use for this term.

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

Octopodiformes is a taxonomic order that includes two main groups: octopuses (Octopoda) and vampire squids (Vampyroteuthis infernalis). This grouping is based on similarities in their fossil record and molecular data. Although they are commonly referred to as squids, vampire squids are not true squids, which belong to a different order called Teuthida.

Octopodiformes are characterized by several features, including:

1. A highly developed brain and complex nervous system.
2. Eight arms with suckers, but no tentacles.
3. The ability to change their skin color and texture for camouflage.
4. Three hearts that pump blood through their bodies.
5. Blue blood due to the copper-based protein hemocyanin.
6. A siphon used for jet propulsion and other functions, such as waste expulsion and mating.
7. Ink sacs for defense against predators.

Octopuses are known for their intelligence, problem-solving abilities, and short lifespans (usually less than two years). Vampire squids, on the other hand, live in deep ocean environments and have a unique feeding strategy that involves filtering organic matter from the water. They can also produce bioluminescent displays to confuse predators.

It is important to note that while Octopodiformes is a well-supported taxonomic group, there is still ongoing research and debate about the relationships among cephalopods (the class that includes octopuses, squids, cuttlefish, and nautiluses) and their classification.

Cell movement, also known as cell motility, refers to the ability of cells to move independently and change their location within tissue or inside the body. This process is essential for various biological functions, including embryonic development, wound healing, immune responses, and cancer metastasis.

There are several types of cell movement, including:

1. **Crawling or mesenchymal migration:** Cells move by extending and retracting protrusions called pseudopodia or filopodia, which contain actin filaments. This type of movement is common in fibroblasts, immune cells, and cancer cells during tissue invasion and metastasis.
2. **Amoeboid migration:** Cells move by changing their shape and squeezing through tight spaces without forming protrusions. This type of movement is often observed in white blood cells (leukocytes) as they migrate through the body to fight infections.
3. **Pseudopodial extension:** Cells extend pseudopodia, which are temporary cytoplasmic projections containing actin filaments. These protrusions help the cell explore its environment and move forward.
4. **Bacterial flagellar motion:** Bacteria use a whip-like structure called a flagellum to propel themselves through their environment. The rotation of the flagellum is driven by a molecular motor in the bacterial cell membrane.
5. **Ciliary and ependymal movement:** Ciliated cells, such as those lining the respiratory tract and fallopian tubes, have hair-like structures called cilia that beat in coordinated waves to move fluids or mucus across the cell surface.

Cell movement is regulated by a complex interplay of signaling pathways, cytoskeletal rearrangements, and adhesion molecules, which enable cells to respond to environmental cues and navigate through tissues.

Monotremata is an order of mammals that lay eggs instead of giving birth to live young. This small group includes the platypus and echidnas, which are native to Australia and New Guinea. These animals are unique because they have characteristics of both reptiles and mammals, making them a fascinating subject of study in evolutionary biology. The order Monotremata is part of the infraclass Eutheria, or placental mammals, even though monotremes lay eggs. This demonstrates the complex evolutionary history of mammals.

Chromosomes are thread-like structures that exist in the nucleus of cells, carrying genetic information in the form of genes. They are composed of DNA and proteins, and are typically present in pairs in the nucleus, with one set inherited from each parent. In humans, there are 23 pairs of chromosomes for a total of 46 chromosomes. Chromosomes come in different shapes and forms, including sex chromosomes (X and Y) that determine the biological sex of an individual. Changes or abnormalities in the number or structure of chromosomes can lead to genetic disorders and diseases.

"Likelihood functions" is a statistical concept that is used in medical research and other fields to estimate the probability of obtaining a given set of data, given a set of assumptions or parameters. In other words, it is a function that describes how likely it is to observe a particular outcome or result, based on a set of model parameters.

More formally, if we have a statistical model that depends on a set of parameters θ, and we observe some data x, then the likelihood function is defined as:

L(θ | x) = P(x | θ)

This means that the likelihood function describes the probability of observing the data x, given a particular value of the parameter vector θ. By convention, the likelihood function is often expressed as a function of the parameters, rather than the data, so we might instead write:

L(θ) = P(x | θ)

The likelihood function can be used to estimate the values of the model parameters that are most consistent with the observed data. This is typically done by finding the value of θ that maximizes the likelihood function, which is known as the maximum likelihood estimator (MLE). The MLE has many desirable statistical properties, including consistency, efficiency, and asymptotic normality.

In medical research, likelihood functions are often used in the context of Bayesian analysis, where they are combined with prior distributions over the model parameters to obtain posterior distributions that reflect both the observed data and prior knowledge or assumptions about the parameter values. This approach is particularly useful when there is uncertainty or ambiguity about the true value of the parameters, as it allows researchers to incorporate this uncertainty into their analyses in a principled way.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

Cichlids are a family (Cichlidae) of freshwater and brackish fish that include several well-known aquarium species. They are found primarily in tropical regions of Africa, Central America, and South America. Cichlids exhibit a wide range of body shapes, sizes, colors, and behaviors, making them popular among aquarists. Some cichlid species are also important sources of food in their native habitats. It is worth noting that cichlids are not typically classified as having medical relevance, but rather they are studied for their ecological, evolutionary, and ornamental significance.

"Sex determination processes" refer to the series of genetic and biological events that occur during embryonic and fetal development which lead to the development of male or female physical characteristics. In humans, this process is typically determined by the presence or absence of a Y chromosome in the fertilized egg. If the egg has a Y chromosome, it will develop into a male (genetically XY) and if it does not have a Y chromosome, it will develop into a female (genetically XX).

The sex determination process involves the activation and repression of specific genes on the sex chromosomes, which direct the development of the gonads (ovaries or testes) and the production of hormones that influence the development of secondary sexual characteristics. This includes the development of internal and external genitalia, as well as other sex-specific physical traits.

It is important to note that while sex is typically determined by genetics and biology, gender identity is a separate construct that can be self-identified and may not align with an individual's biological sex.

Fetal proteins are a type of proteins that are produced by the fetus during pregnancy and can be detected in various biological samples, such as amniotic fluid or maternal blood. These proteins can provide valuable information about the health and development of the fetus. One commonly studied fetal protein is human chorionic gonadotropin (hCG), which is produced by the placenta and can be used as a marker for pregnancy and to detect potential complications, such as Down syndrome or spinal cord defects. Other examples of fetal proteins include alpha-fetoprotein (AFP) and human placental lactogen (hPL).

Paleontology is not a medical field, but rather it is a branch of earth sciences and biology that deals with the study of prehistoric life forms through the examination of plant and animal fossils, including those of extinct organisms. It involves various disciplines such as stratigraphy, geochronology, and systematics to understand the evolutionary history of life on Earth.

However, I understand that you are looking for information related to a non-medical topic, so here is some additional context:

Paleontology can be divided into several subdisciplines, including vertebrate paleontology (the study of fossilized animals with backbones), invertebrate paleontology (the study of fossilized animals without backbones), paleobotany (the study of fossil plants), micropaleontology (the study of microscopic fossils), and taphonomy (the study of the processes that occur after an organism's death, leading to its preservation as a fossil).

Paleontologists use various techniques to study fossils, including comparative anatomy, histology (the study of tissue structure), and geochemistry. They also rely on other scientific fields such as genetics, physics, and chemistry to help them interpret the data they collect from fossils.

Through their research, paleontologists can learn about the morphology, behavior, ecology, and evolutionary relationships of extinct organisms, providing valuable insights into the history of life on Earth.

I apologize for any confusion, but "bass" is not a medical term. It is a term that can have several meanings depending on the context. In music, "bass" refers to a low-pitched sound or instrument. In fishing and aquatic biology, "bass" refers to various species of freshwater fish.

If you are looking for a medical term related to the human body, perhaps you meant "brachial basal sulcus" or "basilar artery." If you can provide more context or clarify your question, I would be happy to help further!

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

Locomotion, in a medical context, refers to the ability to move independently and change location. It involves the coordinated movement of the muscles, bones, and nervous system that enables an individual to move from one place to another. This can include walking, running, jumping, or using assistive devices such as wheelchairs or crutches. Locomotion is a fundamental aspect of human mobility and is often assessed in medical evaluations to determine overall health and functioning.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

The spinal cord is a major part of the nervous system, extending from the brainstem and continuing down to the lower back. It is a slender, tubular bundle of nerve fibers (axons) and support cells (glial cells) that carries signals between the brain and the rest of the body. The spinal cord primarily serves as a conduit for motor information, which travels from the brain to the muscles, and sensory information, which travels from the body to the brain. It also contains neurons that can independently process and respond to information within the spinal cord without direct input from the brain.

The spinal cord is protected by the bony vertebral column (spine) and is divided into 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each segment corresponds to a specific region of the body and gives rise to pairs of spinal nerves that exit through the intervertebral foramina at each level.

The spinal cord is responsible for several vital functions, including:

1. Reflexes: Simple reflex actions, such as the withdrawal reflex when touching a hot surface, are mediated by the spinal cord without involving the brain.
2. Muscle control: The spinal cord carries motor signals from the brain to the muscles, enabling voluntary movement and muscle tone regulation.
3. Sensory perception: The spinal cord transmits sensory information, such as touch, temperature, pain, and vibration, from the body to the brain for processing and awareness.
4. Autonomic functions: The sympathetic and parasympathetic divisions of the autonomic nervous system originate in the thoracolumbar and sacral regions of the spinal cord, respectively, controlling involuntary physiological responses like heart rate, blood pressure, digestion, and respiration.

Damage to the spinal cord can result in various degrees of paralysis or loss of sensation below the level of injury, depending on the severity and location of the damage.

The crystalline lens is a biconvex transparent structure in the eye that helps to refract (bend) light rays and focus them onto the retina. It is located behind the iris and pupil and is suspended by small fibers called zonules that connect it to the ciliary body. The lens can change its shape to accommodate and focus on objects at different distances, a process known as accommodation. With age, the lens may become cloudy or opaque, leading to cataracts.

Vasotocin is not generally recognized as a medical term or a well-established physiological concept in human medicine. However, it is a term used in comparative endocrinology and animal physiology to refer to a nonapeptide hormone that is functionally and structurally similar to arginine vasopressin (AVP) or antidiuretic hormone (ADH) in mammals.

Vasotocin is found in various non-mammalian vertebrates, including fish, amphibians, and reptiles, where it plays roles in regulating water balance, blood pressure, social behaviors, and reproduction. In these animals, vasotocin is produced by the hypothalamus and stored in the posterior pituitary gland before being released into the circulation to exert its effects on target organs.

Therefore, while not a medical definition per se, vasotocin can be defined as a neuropeptide hormone that regulates various physiological functions in non-mammalian vertebrates, with structural and functional similarities to mammalian arginine vasopressin.

"Coturnix" is a genus of birds that includes several species of quails. The most common species is the Common Quail (Coturnix coturnix), which is also known as the European Quail or the Eurasian Quail. This small ground-dwelling bird is found throughout Europe, Asia, and parts of Africa, and it is known for its distinctive call and its migratory habits. Other species in the genus Coturnix include the Rain Quail (Coturnix coromandelica), the Stubble Quail (Coturnix pectoralis), and the Harlequin Quail (Coturnix delegorguei). These birds are all similar in appearance and behavior, with small, round bodies, short wings, and strong legs that are adapted for running and scratching in leaf litter. They are also known for their cryptic coloration, which helps them blend in with their surroundings and avoid predators. Quails are popular game birds and are also kept as pets and for ornamental purposes in some parts of the world.

Cyprinodontiformes is an order of ray-finned fish that includes several families, such as Cyprinodontidae (livebearers), Poeciliidae (including guppies and mollies), Aplocheilidae, Nothobranchiidae, Rivulidae, Valenciidae, Profundulidae, Goodeidae, Anablepidae, and Jenynsiidae. These fish are characterized by their small size, live-bearing reproduction (in most families), and the presence of a urogenital papilla in males. They inhabit a wide range of freshwater and brackish environments, with some species also found in marine habitats. Many cyprinodontiform fishes are popular as aquarium pets due to their vibrant colors and interesting behaviors.

Cyprinidae is a family of fish that includes carps, minnows, and barbs. It is the largest family of freshwater fish, with over 2,400 species found worldwide, particularly in Asia and Europe. These fish are characterized by their lack of teeth on the roof of their mouths and have a single dorsal fin. Some members of this family are economically important as food fish or for aquarium trade.

Computational biology is a branch of biology that uses mathematical and computational methods to study biological data, models, and processes. It involves the development and application of algorithms, statistical models, and computational approaches to analyze and interpret large-scale molecular and phenotypic data from genomics, transcriptomics, proteomics, metabolomics, and other high-throughput technologies. The goal is to gain insights into biological systems and processes, develop predictive models, and inform experimental design and hypothesis testing in the life sciences. Computational biology encompasses a wide range of disciplines, including bioinformatics, systems biology, computational genomics, network biology, and mathematical modeling of biological systems.

Striated muscle, also known as skeletal or voluntary muscle, is a type of muscle tissue that is characterized by the presence of distinct light and dark bands, or striations, when viewed under a microscope. These striations correspond to the arrangement of sarcomeres, which are the functional units of muscle fibers.

Striated muscle is under voluntary control, meaning that it is consciously activated by signals from the nervous system. It is attached to bones via tendons and is responsible for producing movements of the body. Striated muscle fibers are multinucleated, meaning that they contain many nuclei, and are composed of numerous myofibrils, which are rope-like structures that run the length of the fiber.

The myofibrils are composed of thick and thin filaments that slide past each other to cause muscle contraction. The thick filaments are made up of the protein myosin, while the thin filaments are composed of actin, tropomyosin, and troponin. When a nerve impulse arrives at the muscle fiber, it triggers the release of calcium ions from the sarcoplasmic reticulum, which bind to troponin and cause a conformational change that exposes the binding sites on actin for myosin. The myosin heads then bind to the actin filaments and pull them towards the center of the sarcomere, causing the muscle fiber to shorten and contract.

Retinal cone photoreceptor cells are specialized neurons located in the retina of the eye, responsible for visual phototransduction and color vision. They are one of the two types of photoreceptors, with the other being rods, which are more sensitive to low light levels. Cones are primarily responsible for high-acuity, color vision during daylight or bright-light conditions.

There are three types of cone cells, each containing different photopigments that absorb light at distinct wavelengths: short (S), medium (M), and long (L) wavelengths, which correspond to blue, green, and red light, respectively. The combination of signals from these three types of cones allows the human visual system to perceive a wide range of colors and discriminate between them. Cones are densely packed in the central region of the retina, known as the fovea, which provides the highest visual acuity.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Pseudogenes are defined in medical and genetics terminology as non-functional segments of DNA that resemble functional genes, such as protein-coding genes or RNA genes, but have lost their ability to be expressed or produce a functional product. They are often characterized by the presence of mutations, such as frameshifts, premature stop codons, or deletions, that prevent them from being transcribed or translated into functional proteins or RNAs.

Pseudogenes can arise through various mechanisms, including gene duplication followed by degenerative mutations, retrotransposition of processed mRNA, and the insertion of transposable elements. While they were once considered "genomic fossils" with no biological relevance, recent research has shown that pseudogenes may play important roles in regulating gene expression, modulating protein function, and contributing to disease processes.

It's worth noting that there is ongoing debate in the scientific community about the precise definition and functional significance of pseudogenes, as some may still retain residual functions or regulatory potential.

Isochores are large genomic regions that share a similar base composition, specifically in terms of GC content (the percentage of guanine and cytosine bases in DNA). They were first identified in mammalian genomes and are now known to be a common feature in many vertebrate and invertebrate species. Isochores can vary in size from several thousand to millions of base pairs, and they often correspond to distinct functional elements within the genome, such as gene-rich or gene-poor regions. The study of isochores has provided valuable insights into the evolutionary processes that shape genomes and the functional constraints that act on different genomic regions.

Rhodopsin, also known as visual purple, is a light-sensitive pigment found in the rods of the vertebrate retina. It is a complex protein molecule made up of two major components: an opsin protein and retinal, a form of vitamin A. When light hits the retinal in rhodopsin, it changes shape, which initiates a series of chemical reactions leading to the activation of the visual pathway and ultimately results in vision. This process is known as phototransduction. Rhodopsin plays a crucial role in low-light vision or scotopic vision.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

The PAX2 transcription factor is a protein that plays a crucial role in the development and function of the kidneys and urinary system. It belongs to the PAX family of transcription factors, which are characterized by a highly conserved DNA-binding domain called the paired box. The PAX2 protein helps regulate gene expression during embryonic development, including genes involved in the formation of the nephrons, the functional units of the kidneys.

PAX2 is expressed in the intermediate mesoderm, which gives rise to the kidneys and other organs of the urinary system. It helps to specify the fate of these cells and promote their differentiation into mature kidney structures. In addition to its role in kidney development, PAX2 has also been implicated in the development of the eye, ear, and central nervous system.

Mutations in the PAX2 gene have been associated with various genetic disorders, including renal coloboma syndrome, which is characterized by kidney abnormalities and eye defects. Proper regulation of PAX2 expression is essential for normal development and function of the urinary system and other organs.

Bone Morphogenetic Protein 4 (BMP-4) is a growth factor that belongs to the transforming growth factor-beta (TGF-β) superfamily. It plays crucial roles in various biological processes, including embryonic development, cell growth, and differentiation. In the skeletal system, BMP-4 stimulates the formation of bone and cartilage by inducing the differentiation of mesenchymal stem cells into chondrocytes and osteoblasts. It also regulates the maintenance and repair of bones throughout life. An imbalance in BMP-4 signaling has been associated with several skeletal disorders, such as heterotopic ossification and osteoarthritis.

Amino acid motifs are recurring patterns or sequences of amino acids in a protein molecule. These motifs can be identified through various sequence analysis techniques and often have functional or structural significance. They can be as short as two amino acids in length, but typically contain at least three to five residues.

Some common examples of amino acid motifs include:

1. Active site motifs: These are specific sequences of amino acids that form the active site of an enzyme and participate in catalyzing chemical reactions. For example, the catalytic triad in serine proteases consists of three residues (serine, histidine, and aspartate) that work together to hydrolyze peptide bonds.
2. Signal peptide motifs: These are sequences of amino acids that target proteins for secretion or localization to specific organelles within the cell. For example, a typical signal peptide consists of a positively charged n-region, a hydrophobic h-region, and a polar c-region that directs the protein to the endoplasmic reticulum membrane for translocation.
3. Zinc finger motifs: These are structural domains that contain conserved sequences of amino acids that bind zinc ions and play important roles in DNA recognition and regulation of gene expression.
4. Transmembrane motifs: These are sequences of hydrophobic amino acids that span the lipid bilayer of cell membranes and anchor transmembrane proteins in place.
5. Phosphorylation sites: These are specific serine, threonine, or tyrosine residues that can be phosphorylated by protein kinases to regulate protein function.

Understanding amino acid motifs is important for predicting protein structure and function, as well as for identifying potential drug targets in disease-associated proteins.

The ear is the sensory organ responsible for hearing and maintaining balance. It can be divided into three parts: the outer ear, middle ear, and inner ear. The outer ear consists of the pinna (the visible part of the ear) and the external auditory canal, which directs sound waves toward the eardrum. The middle ear contains three small bones called ossicles that transmit sound vibrations from the eardrum to the inner ear. The inner ear contains the cochlea, a spiral-shaped organ responsible for converting sound vibrations into electrical signals that are sent to the brain, and the vestibular system, which is responsible for maintaining balance.

Annelida is a phylum of bilaterally symmetrical, segmented animals that includes earthworms, leeches, and marine polychaetes (bristle worms). The name "Annelida" comes from the Latin word "annellus," meaning "little ring," which refers to the distinct segments found in these animals.

Each segment in annelids contains a pair of bundled nerves called the ventral nerve cord, and many also contain circular and longitudinal muscles that enable the animal to move by contracting and relaxing these muscles in a wave-like motion. Some annelids have specialized segments for functions such as reproduction or respiration.

Annelids are primarily aquatic animals, although some terrestrial species like earthworms have evolved to live on land. They vary in size from tiny marine worms that are only a few millimeters long to large marine polychaetes that can reach over a meter in length.

Annelids are important decomposers and help break down dead organic matter, returning nutrients to the soil or water. Some species of annelids are also parasitic, feeding on the blood or tissues of other animals. Overall, annelids play a crucial role in many aquatic and terrestrial ecosystems.

Auditory hair cells are specialized sensory receptor cells located in the inner ear, more specifically in the organ of Corti within the cochlea. They play a crucial role in hearing by converting sound vibrations into electrical signals that can be interpreted by the brain.

These hair cells have hair-like projections called stereocilia on their apical surface, which are embedded in a gelatinous matrix. When sound waves reach the inner ear, they cause the fluid within the cochlea to move, which in turn causes the stereocilia to bend. This bending motion opens ion channels at the tips of the stereocilia, allowing positively charged ions (such as potassium) to flow into the hair cells and trigger a receptor potential.

The receptor potential then leads to the release of neurotransmitters at the base of the hair cells, which activate afferent nerve fibers that synapse with these cells. The electrical signals generated by this process are transmitted to the brain via the auditory nerve, where they are interpreted as sound.

There are two types of auditory hair cells: inner hair cells and outer hair cells. Inner hair cells are the primary sensory receptors responsible for transmitting information about sound to the brain. They make direct contact with afferent nerve fibers and are more sensitive to mechanical stimulation than outer hair cells.

Outer hair cells, on the other hand, are involved in amplifying and fine-tuning the mechanical response of the inner ear to sound. They have a unique ability to contract and relax in response to electrical signals, which allows them to adjust the stiffness of their stereocilia and enhance the sensitivity of the cochlea to different frequencies.

Damage or loss of auditory hair cells can lead to hearing impairment or deafness, as these cells cannot regenerate spontaneously in mammals. Therefore, understanding the structure and function of hair cells is essential for developing therapies aimed at treating hearing disorders.

Tretinoin is a form of vitamin A that is used in the treatment of acne vulgaris, fine wrinkles, and dark spots caused by aging or sun damage. It works by increasing the turnover of skin cells, helping to unclog pores and promote the growth of new skin cells. Tretinoin is available as a cream, gel, or liquid, and is usually applied to the affected area once a day in the evening. Common side effects include redness, dryness, and peeling of the skin. It is important to avoid sunlight and use sunscreen while using tretinoin, as it can make the skin more sensitive to the sun.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Cnidaria is a phylum of aquatic animals that includes jellyfish, sea anemones, hydra, and corals. They are characterized by the presence of specialized stinging cells called cnidocytes, which they use for defense and capturing prey. Cnidarians have a simple body organization with two basic forms: polyps, which are typically cylindrical and attached to a substrate; and medusae, which are free-swimming and bell-shaped. Some species can exist in both forms during their life cycle.

Cnidarians have no true organs or organ systems, but they do have a unique tissue arrangement with two main layers: an outer epidermis and an inner gastrodermis, separated by a jelly-like mesoglea. They have a digestive cavity called the coelenteron, where they absorb nutrients after capturing and digesting prey. Cnidarians reproduce both sexually and asexually, with some species exhibiting complex life cycles involving multiple forms and reproductive strategies.

Comparative anatomy is a branch of biology and medicine that deals with the study and comparison of the structures and functions of different species, including humans. It involves the examination of similarities and differences in the anatomy of various organisms to understand their evolutionary relationships and adaptations. This field helps scientists to understand the development and function of body structures, as well as the evolutionary history of different species. By comparing and contrasting the anatomy of different organisms, researchers can gain insights into the functions and workings of various bodily systems and how they have evolved over time.

Neurogenesis is the process by which new neurons (nerve cells) are generated in the brain. It occurs throughout life in certain areas of the brain, such as the hippocampus and subventricular zone, although the rate of neurogenesis decreases with age. Neurogenesis involves the proliferation, differentiation, and integration of new neurons into existing neural circuits. This process plays a crucial role in learning, memory, and recovery from brain injury or disease.

SOXB2 transcription factors are a subgroup of the SOX (SRY-related HMG box) family of proteins, which are involved in various developmental processes. The SOXB2 group includes SOX1, SOX2, and SOX3, which share similar structures and functions. These transcription factors play crucial roles in the determination and maintenance of cell fate, particularly during neural development. They regulate gene expression by binding to specific DNA sequences and influencing the transcription of nearby genes. SOXB2 proteins have been implicated in the development and maintenance of stem cells, as well as in the onset and progression of certain cancers when their regulation is disrupted.

Gonads are the reproductive organs that produce gametes (sex cells) and sex hormones. In males, the gonads are the testes, which produce sperm and testosterone. In females, the gonads are the ovaries, which produce eggs and estrogen and progesterone. The development, function, and regulation of the gonads are crucial for reproductive health and fertility.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

Feeding behavior refers to the various actions and mechanisms involved in the intake of food and nutrition for the purpose of sustaining life, growth, and health. This complex process encompasses a coordinated series of activities, including:

1. Food selection: The identification, pursuit, and acquisition of appropriate food sources based on sensory cues (smell, taste, appearance) and individual preferences.
2. Preparation: The manipulation and processing of food to make it suitable for consumption, such as chewing, grinding, or chopping.
3. Ingestion: The act of transferring food from the oral cavity into the digestive system through swallowing.
4. Digestion: The mechanical and chemical breakdown of food within the gastrointestinal tract to facilitate nutrient absorption and eliminate waste products.
5. Assimilation: The uptake and utilization of absorbed nutrients by cells and tissues for energy production, growth, repair, and maintenance.
6. Elimination: The removal of undigested material and waste products from the body through defecation.

Feeding behavior is regulated by a complex interplay between neural, hormonal, and psychological factors that help maintain energy balance and ensure adequate nutrient intake. Disruptions in feeding behavior can lead to various medical conditions, such as malnutrition, obesity, eating disorders, and gastrointestinal motility disorders.

"Body size" is a general term that refers to the overall physical dimensions and proportions of an individual's body. It can encompass various measurements, including height, weight, waist circumference, hip circumference, blood pressure, and other anthropometric measures.

In medical and public health contexts, body size is often used to assess health status, risk factors for chronic diseases, and overall well-being. For example, a high body mass index (BMI) may indicate excess body fat and increase the risk of conditions such as diabetes, hypertension, and cardiovascular disease. Similarly, a large waist circumference or high blood pressure may also be indicators of increased health risks.

It's important to note that body size is just one aspect of health and should not be used as the sole indicator of an individual's overall well-being. A holistic approach to health that considers multiple factors, including diet, physical activity, mental health, and social determinants of health, is essential for promoting optimal health outcomes.

Wnt1 protein is a member of the Wnt family, which is a group of secreted signaling proteins that play crucial roles in embryonic development and tissue homeostasis in adults. Specifically, Wnt1 is a highly conserved gene that encodes a glycoprotein with a molecular weight of approximately 40 kDa. It is primarily expressed in the developing nervous system, where it functions as a key regulator of neural crest cell migration and differentiation during embryogenesis.

Wnt1 protein mediates its effects by binding to Frizzled receptors on the surface of target cells, leading to the activation of several intracellular signaling pathways, including the canonical Wnt/β-catenin pathway and non-canonical Wnt/planar cell polarity (PCP) pathway. In the canonical pathway, Wnt1 protein stabilizes β-catenin, which then translocates to the nucleus and interacts with TCF/LEF transcription factors to regulate gene expression.

Dysregulation of Wnt1 signaling has been implicated in several human diseases, including cancer. For example, aberrant activation of the Wnt/β-catenin pathway by Wnt1 protein has been observed in various types of tumors, such as medulloblastomas and breast cancers, leading to uncontrolled cell proliferation and tumor growth. Therefore, understanding the molecular mechanisms underlying Wnt1 signaling is essential for developing novel therapeutic strategies for treating these diseases.

An animal model in medicine refers to the use of non-human animals in experiments to understand, predict, and test responses and effects of various biological and chemical interactions that may also occur in humans. These models are used when studying complex systems or processes that cannot be easily replicated or studied in human subjects, such as genetic manipulation or exposure to harmful substances. The choice of animal model depends on the specific research question being asked and the similarities between the animal's and human's biological and physiological responses. Examples of commonly used animal models include mice, rats, rabbits, guinea pigs, and non-human primates.

Motor neurons are specialized nerve cells in the brain and spinal cord that play a crucial role in controlling voluntary muscle movements. They transmit electrical signals from the brain to the muscles, enabling us to perform actions such as walking, talking, and swallowing. There are two types of motor neurons: upper motor neurons, which originate in the brain's motor cortex and travel down to the brainstem and spinal cord; and lower motor neurons, which extend from the brainstem and spinal cord to the muscles. Damage or degeneration of these motor neurons can lead to various neurological disorders, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA).

A "reporter gene" is a type of gene that is linked to a gene of interest in order to make the expression or activity of that gene detectable. The reporter gene encodes for a protein that can be easily measured and serves as an indicator of the presence and activity of the gene of interest. Commonly used reporter genes include those that encode for fluorescent proteins, enzymes that catalyze colorimetric reactions, or proteins that bind to specific molecules.

In the context of genetics and genomics research, a reporter gene is often used in studies involving gene expression, regulation, and function. By introducing the reporter gene into an organism or cell, researchers can monitor the activity of the gene of interest in real-time or after various experimental treatments. The information obtained from these studies can help elucidate the role of specific genes in biological processes and diseases, providing valuable insights for basic research and therapeutic development.

G-protein-coupled receptors (GPCRs) are a family of membrane receptors that play an essential role in cellular signaling and communication. These receptors possess seven transmembrane domains, forming a structure that spans the lipid bilayer of the cell membrane. They are called "G-protein-coupled" because they interact with heterotrimeric G proteins upon activation, which in turn modulate various downstream signaling pathways.

When an extracellular ligand binds to a GPCR, it causes a conformational change in the receptor's structure, leading to the exchange of guanosine diphosphate (GDP) for guanosine triphosphate (GTP) on the associated G protein's α subunit. This exchange triggers the dissociation of the G protein into its α and βγ subunits, which then interact with various effector proteins to elicit cellular responses.

There are four main families of GPCRs, classified based on their sequence similarities and downstream signaling pathways:

1. Gq-coupled receptors: These receptors activate phospholipase C (PLC), which leads to the production of inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 induces calcium release from intracellular stores, while DAG activates protein kinase C (PKC).
2. Gs-coupled receptors: These receptors activate adenylyl cyclase, which increases the production of cyclic adenosine monophosphate (cAMP) and subsequently activates protein kinase A (PKA).
3. Gi/o-coupled receptors: These receptors inhibit adenylyl cyclase, reducing cAMP levels and modulating PKA activity. Additionally, they can activate ion channels or regulate other signaling pathways through the βγ subunits.
4. G12/13-coupled receptors: These receptors primarily activate RhoGEFs, which in turn activate RhoA and modulate cytoskeletal organization and cellular motility.

GPCRs are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and sensory perception. Dysregulation of GPCR function has been implicated in numerous diseases, making them attractive targets for drug development.

Gene targeting is a research technique in molecular biology used to precisely modify specific genes within the genome of an organism. This technique allows scientists to study gene function by creating targeted genetic changes, such as insertions, deletions, or mutations, in a specific gene of interest. The process typically involves the use of engineered nucleases, such as CRISPR-Cas9 or TALENs, to introduce double-stranded breaks at desired locations within the genome. These breaks are then repaired by the cell's own DNA repair machinery, often leading to the incorporation of designed changes in the targeted gene. Gene targeting is a powerful tool for understanding gene function and has wide-ranging applications in basic research, agriculture, and therapeutic development.

I'm sorry for any confusion, but "killifishes" is not a term used in medical definitions. Killifishes are a type of small, freshwater or saltwater fish that belong to the family Cyprinodontidae. They are known for their bright colors and patterns, and are often kept as aquarium pets. If you have any questions about biology or animal species, I'd be happy to try to help answer them!

I'm sorry for any confusion, but "swimming" is not typically considered a medical term. It refers to the act of moving through water using your arms and legs in a rhythmic pattern, often as a form of exercise, recreation, or competition. However, if you're referring to a medical condition related to swimming, such as "swimmer's ear" (otitis externa), I would be happy to provide a definition for that.

Swimmer's ear is a type of outer ear infection caused by water remaining in the ear after swimming or bathing, creating a moist environment that can lead to bacterial growth. It can also be caused by scratching or damaging the lining of the ear canal through the use of cotton swabs or other objects. Symptoms may include itching, redness, pain, and sometimes discharge from the ear. If left untreated, swimmer's ear can lead to more serious complications, such as hearing loss or damage to the inner ear.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Mitosis is a type of cell division in which the genetic material of a single cell, called the mother cell, is equally distributed into two identical daughter cells. It's a fundamental process that occurs in multicellular organisms for growth, maintenance, and repair, as well as in unicellular organisms for reproduction.

The process of mitosis can be broken down into several stages: prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the chromosomes condense and become visible, and the nuclear envelope breaks down. In prometaphase, the nuclear membrane is completely disassembled, and the mitotic spindle fibers attach to the chromosomes at their centromeres.

During metaphase, the chromosomes align at the metaphase plate, an imaginary line equidistant from the two spindle poles. In anaphase, sister chromatids are pulled apart by the spindle fibers and move toward opposite poles of the cell. Finally, in telophase, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense and become less visible.

Mitosis is followed by cytokinesis, a process that divides the cytoplasm of the mother cell into two separate daughter cells. The result of mitosis and cytokinesis is two genetically identical cells, each with the same number and kind of chromosomes as the original parent cell.

LIM-homeodomain proteins are a family of transcription factors that contain both LIM domains and homeodomains. LIM domains are cysteine-rich motifs that function in protein-protein interactions, often mediating the formation of multimeric complexes. Homeodomains are DNA-binding domains that recognize and bind to specific DNA sequences, thereby regulating gene transcription.

LIM-homeodomain proteins play important roles in various developmental processes, including cell fate determination, differentiation, and migration. They have been implicated in the regulation of muscle, nerve, and cardiovascular development, as well as in cancer and other diseases. Some examples of LIM-homeodomain proteins include LMX1A, LHX2, and ISL1.

These proteins are characterized by the presence of two LIM domains at the N-terminus and a homeodomain at the C-terminus. The LIM domains are involved in protein-protein interactions, while the homeodomain is responsible for DNA binding and transcriptional regulation. Some LIM-homeodomain proteins also contain other functional domains, such as zinc fingers or leucine zippers, which contribute to their diverse functions.

Overall, LIM-homeodomain proteins are important regulators of gene expression and play critical roles in various developmental and disease processes.

'Animal behavior' refers to the actions or responses of animals to various stimuli, including their interactions with the environment and other individuals. It is the study of the actions of animals, whether they are instinctual, learned, or a combination of both. Animal behavior includes communication, mating, foraging, predator avoidance, and social organization, among other things. The scientific study of animal behavior is called ethology. This field seeks to understand the evolutionary basis for behaviors as well as their physiological and psychological mechanisms.

The olfactory pathways refer to the neural connections and structures involved in the sense of smell. The process begins with odor molecules that are inhaled through the nostrils, where they bind to specialized receptor cells located in the upper part of the nasal cavity, known as the olfactory epithelium.

These receptor cells then transmit signals via the olfactory nerve (cranial nerve I) to the olfactory bulb, a structure at the base of the brain. Within the olfactory bulb, the signals are processed and relayed through several additional structures, including the olfactory tract, lateral olfactory striae, and the primary olfactory cortex (located within the piriform cortex).

From there, information about odors is further integrated with other sensory systems and cognitive functions in higher-order brain regions, such as the limbic system, thalamus, and hippocampus. This complex network of olfactory pathways allows us to perceive and recognize various scents and plays a role in emotional responses, memory formation, and feeding behaviors.

Antisense oligonucleotides (ASOs) are short synthetic single stranded DNA-like molecules that are designed to complementarily bind to a specific RNA sequence through base-pairing, with the goal of preventing the translation of the target RNA into protein or promoting its degradation.

The antisense oligonucleotides work by hybridizing to the targeted messenger RNA (mRNA) molecule and inducing RNase H-mediated degradation, sterically blocking ribosomal translation, or modulating alternative splicing of the pre-mRNA.

ASOs have shown promise as therapeutic agents for various genetic diseases, viral infections, and cancers by specifically targeting disease-causing genes. However, their clinical application is still facing challenges such as off-target effects, stability, delivery, and potential immunogenicity.

A tooth is a hard, calcified structure found in the jaws (upper and lower) of many vertebrates and used for biting and chewing food. In humans, a typical tooth has a crown, one or more roots, and three layers: the enamel (the outermost layer, hardest substance in the body), the dentin (the layer beneath the enamel), and the pulp (the innermost layer, containing nerves and blood vessels). Teeth are essential for proper nutrition, speech, and aesthetics. There are different types of teeth, including incisors, canines, premolars, and molars, each designed for specific functions in the mouth.

In medical terms, the heart is a muscular organ located in the thoracic cavity that functions as a pump to circulate blood throughout the body. It's responsible for delivering oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. The human heart is divided into four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it out to the rest of the body. The heart's rhythmic contractions and relaxations are regulated by a complex electrical conduction system.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

The mesencephalon, also known as the midbrain, is the middle portion of the brainstem that connects the hindbrain (rhombencephalon) and the forebrain (prosencephalon). It plays a crucial role in several important functions including motor control, vision, hearing, and the regulation of consciousness and sleep-wake cycles. The mesencephalon contains several important structures such as the cerebral aqueduct, tectum, tegmentum, cerebral peduncles, and several cranial nerve nuclei (III and IV).

Gene knockdown techniques are methods used to reduce the expression or function of specific genes in order to study their role in biological processes. These techniques typically involve the use of small RNA molecules, such as siRNAs (small interfering RNAs) or shRNAs (short hairpin RNAs), which bind to and promote the degradation of complementary mRNA transcripts. This results in a decrease in the production of the protein encoded by the targeted gene.

Gene knockdown techniques are often used as an alternative to traditional gene knockout methods, which involve completely removing or disrupting the function of a gene. Knockdown techniques allow for more subtle and reversible manipulation of gene expression, making them useful for studying genes that are essential for cell survival or have redundant functions.

These techniques are widely used in molecular biology research to investigate gene function, genetic interactions, and disease mechanisms. However, it is important to note that gene knockdown can have off-target effects and may not completely eliminate the expression of the targeted gene, so results should be interpreted with caution.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

Iguanas are not a medical term. They refer to a type of large, herbivorous lizard that is native to Central and South America, as well as the Caribbean. Some species of iguanas are also found in Mexico and parts of the southern United States. The green iguana is the most common species kept as pets. If you're looking for a medical definition, it might be a case of mistaken identity or misspelling, please make sure the term is correct.

SOX (SRY-related HMG box) transcription factors are a family of proteins that regulate gene expression during embryonic development and in adult tissues. They contain a highly conserved DNA-binding domain, the HMG box, which allows them to bind to specific DNA sequences and influence the transcription of nearby genes. SOX proteins play critical roles in various biological processes such as cell fate determination, differentiation, proliferation, and survival.

SOX transcription factors are classified into several groups (A-H) based on their sequence similarities and functional redundancies. Some well-known members of this family include SOX1, SOX2, SOX3, SOX4, SOX9, SOX10, and SOX17. These proteins often form complexes with other transcription factors or cofactors to modulate their target genes' expression.

Dysregulation of SOX transcription factors has been implicated in several human diseases, including cancer, developmental disorders, and degenerative conditions. For example, SOX2 overexpression is associated with certain types of tumors, while mutations in the SOX9 gene can cause campomelic dysplasia, a severe skeletal disorder.

"Eels" is not a term that has a medical definition. It refers to a type of long, snake-like fish that belong to the order Anguilliformes. There are several species of eels found in fresh and saltwater environments around the world. While there may be some references to "eels" in a medical context, such as in the name of certain medical conditions or procedures, these would be specific and unrelated to the fish themselves.

I'm sorry for any confusion, but "grasshoppers" is not a term used in medical definitions. Grasshoppers are a type of insect that belongs to the order Orthoptera and suborder Caelifera. They are known for their long hind legs which they use for jumping, and some species can jump over 20 times their own body length. If you have any questions about medical terminology or topics, I'd be happy to help with those instead!

Batrachoidiformes is an order of primarily marine ray-finned fish that includes the genera Batrachoides, Halophryne, Porichthys, and Thalassophryne. These fish are characterized by having a stout body, large head, and strong, bony mouthparts. They are often called "toadfish" due to their warty skin and toad-like appearance. Some species have the ability to produce sounds, which they use for communication and mating. They are found in tropical and subtropical waters of the Atlantic and Pacific Oceans, as well as in the Mediterranean Sea.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

Neuroepithelial cells are stem cells that line the developing central nervous system (CNS) in embryos. These cells have the ability to differentiate into various cell types, including neurons and glial cells, which make up the brain and spinal cord. Neuroepithelial cells form a pseudostratified epithelium, meaning that the nuclei of the cells are at varying heights within the cell layer, giving it a striped appearance. These cells play a crucial role in the development and growth of the CNS.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

I'm sorry for any confusion, but "Salmon" is not a medical term. It is a common name for various species of fish that belong to the family Salmonidae and are known for their distinctive pink or red flesh. They are an important source of food and are popular in many cuisines around the world. If you have any questions about medical terminology, I'd be happy to help with those instead!

'Culicidae' is the biological family that includes all species of mosquitoes. It consists of three subfamilies: Anophelinae, Culicinae, and Toxorhynchitinae. Mosquitoes are small, midge-like flies that are known for their ability to transmit various diseases to humans and other animals, such as malaria, yellow fever, dengue fever, and Zika virus. The medical importance of Culicidae comes from the fact that only female mosquitoes require blood meals to lay eggs, and during this process, they can transmit pathogens between hosts.

I'm sorry for any confusion, but "trout" is not a term typically used in medical definitions. Trout is a common name that refers to several species of freshwater fish belonging to the salmonid family. If you have any questions related to medical terminology or health concerns, I would be happy to try and help answer those for you.

I'm sorry for any confusion, but "Hydra" is not a term commonly used in medical definitions. Hydra is a genus of small, simple aquatic animals, belonging to the class Hydrozoa in the phylum Cnidaria. They are named after the multi-headed creature from Greek mythology due to their ability to regenerate lost body parts.

If you're looking for a medical term related to hydra, one possibility could be "Hydralazine," which is a medication used to treat high blood pressure. It works by relaxing the muscle in the walls of blood vessels, causing them to widen and the blood to flow more easily.

I hope this information is helpful! If you have any other questions or need clarification on a different topic, please let me know.

Retinal pigments refer to the light-sensitive chemicals found in the retina, specifically within the photoreceptor cells called rods and cones. The main types of retinal pigments are rhodopsin (also known as visual purple) in rods and iodopsins in cones. These pigments play a crucial role in the process of vision by absorbing light and initiating a series of chemical reactions that ultimately trigger nerve impulses, which are then transmitted to the brain and interpreted as visual images. Rhodopsin is more sensitive to lower light levels and is responsible for night vision, while iodopsins are sensitive to specific wavelengths of light and contribute to color vision.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

Sexual behavior in animals refers to a variety of behaviors related to reproduction and mating that occur between members of the same species. These behaviors can include courtship displays, mating rituals, and various physical acts. The specific forms of sexual behavior displayed by a given species are influenced by a combination of genetic, hormonal, and environmental factors.

In some animals, sexual behavior is closely tied to reproductive cycles and may only occur during certain times of the year or under specific conditions. In other species, sexual behavior may be more frequent and less closely tied to reproduction, serving instead as a means of social bonding or communication.

It's important to note that while humans are animals, the term "sexual behavior" is often used in a more specific sense to refer to sexual activities between human beings. The study of sexual behavior in animals is an important area of research within the field of animal behavior and can provide insights into the evolutionary origins of human sexual behavior as well as the underlying mechanisms that drive it.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

Hemocytes are specialized cells found in the open circulatory system of invertebrates, including insects, crustaceans, and mollusks. They play crucial roles in the immune response and defense mechanisms of these organisms. Hemocytes can be categorized into several types based on their functions and morphologies, such as phagocytic cells, encapsulating cells, and clotting cells. These cells are responsible for various immunological activities, including recognition and removal of foreign particles, pathogens, and debris; production of immune effector molecules; and contribution to the formation of blood clots to prevent excessive bleeding. In some invertebrates, hemocytes also participate in wound healing, tissue repair, and other physiological processes.

Mitochondrial DNA (mtDNA) is the genetic material present in the mitochondria, which are specialized structures within cells that generate energy. Unlike nuclear DNA, which is present in the cell nucleus and inherited from both parents, mtDNA is inherited solely from the mother.

MtDNA is a circular molecule that contains 37 genes, including 13 genes that encode for proteins involved in oxidative phosphorylation, a process that generates energy in the form of ATP. The remaining genes encode for rRNAs and tRNAs, which are necessary for protein synthesis within the mitochondria.

Mutations in mtDNA can lead to a variety of genetic disorders, including mitochondrial diseases, which can affect any organ system in the body. These mutations can also be used in forensic science to identify individuals and establish biological relationships.

Myosins are a large family of motor proteins that play a crucial role in various cellular processes, including muscle contraction and intracellular transport. They consist of heavy chains, which contain the motor domain responsible for generating force and motion, and light chains, which regulate the activity of the myosin. Based on their structural and functional differences, myosins are classified into over 35 classes, with classes II, V, and VI being the most well-studied.

Class II myosins, also known as conventional myosins, are responsible for muscle contraction in skeletal, cardiac, and smooth muscles. They form filaments called thick filaments, which interact with actin filaments to generate force and movement during muscle contraction.

Class V myosins, also known as unconventional myosins, are involved in intracellular transport and organelle positioning. They have a long tail that can bind to various cargoes, such as vesicles, mitochondria, and nuclei, and a motor domain that moves along actin filaments to transport the cargoes to their destinations.

Class VI myosins are also unconventional myosins involved in intracellular transport and organelle positioning. They have two heads connected by a coiled-coil tail, which can bind to various cargoes. Class VI myosins move along actin filaments in a unique hand-over-hand motion, allowing them to transport their cargoes efficiently.

Overall, myosins are essential for many cellular functions and have been implicated in various diseases, including cardiovascular diseases, neurological disorders, and cancer.

With the evolution of the jaw in the early jawed vertebrates, this gill slit was caught between the forward gill-rod (now ... Romer, A.S. (1949): The Vertebrate Body. W.B. Saunders, Philadelphia. (2nd ed. 1955; 3rd ed. 1962; 4th ed. 1970) "Will a Shark ... Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 316- ... Pages with plain IPA, Respiratory system, Vertebrate anatomy). ...
... which in vertebrates, depending on the species, may include the ureter, urinary bladder, cloaca, and urethra. All vertebrates ... and in many vertebrates also produces hormones (in particular, renin) and maintains blood pressure. In healthy vertebrates, the ... and is also found in the embryos of some more developed vertebrates. In lower vertebrates, the pronephros is sometimes called ... replacing each other and reflecting the evolution of the kidneys in vertebrates. At the very beginning of vertebrates, when ...
... mimicry in vertebrates is mimicry by a vertebrate of some model (an animal, not necessarily a vertebrate), deceiving some other ... There are few well-studied examples of mimicry in vertebrates. Still, many of the basic types of mimicry apply to vertebrates, ... and may help to explain the relative scarcity of precise mimicry in vertebrates. Vertebrates seem to have multiple barriers to ... Some vertebrates species self-mimic their own body parts, through the use of patterns or actual anatomy. Two widespread ...
In the book vertebrate evolution is studied utilizing comparative anatomy & functional morphology of existing vertebrates, and ... Evolution of the Vertebrates, subtitled "A History of the Backboned Animals Through Time" is a basic paleontology textbook by ... Edwin H. Colbert, (1969), Evolution of the Vertebrates, John Wiley & Sons (2nd ed.) Edwin H. Colbert, Michael Morales, Eli C. ... The first and second editions (1955 and 1969) provide an overview of the entire range of vertebrate evolution, and are ...
... Oxford : Clarendon. My Book Of A Lifetime: The Life of Vertebrates by J. Z. Young. Reviewed by Colin ... The Life of Vertebrates is a noted biology textbook by John Zachary Young. The book grew out of the author's attempt to define ... It combined an account of the embryology, anatomy, physiology, biochemistry, palaeontology, and ecology of all vertebrates and ... Taxonomy of the vertebrates (Young, 1962) Young, J. Z. (1950). "Preface". ...
Vertebrate maternal behavior is a form of parental care that is specifically given to young animals by their mother in order to ... The only vertebrate species to practice brood parasitism other than birds is the cuckoo catfish. These fish prey specifically ... Although maternal care is essential in many classes of vertebrates, it is the most prevalent in mammals, since the care from ... This maternal behavior is unique from all other vertebrate classes. The basic maternal care patterns in mammals involve the ...
The word vertebrate derives from the Latin word vertebratus (Pliny), meaning joint of the spine. Vertebrate is derived from the ... "Vertebrates: More on Morphology". UCMP. Retrieved 13 July 2011. Romer, A.S. (1949): The Vertebrate Body. W.B. Saunders, ... Vertebrates comprise such groups as the following: jawless fish, which include hagfish and lampreys jawed vertebrates, which ... Vertebrates originated during the Cambrian explosion, which saw a rise in organism diversity. The earliest known vertebrates ...
Marine vertebrates are vertebrates that live in marine environments. These are the marine fish and the marine tetrapods ( ... The lampreys are a very ancient lineage of vertebrates, though their exact relationship to hagfishes and jawed vertebrates is ... ancestral to jawed vertebrates Pteraspidomorphi is an extinct class of early jawless fish ancestral to jawed vertebrates. The ... A jawless vertebrate model system for examining origin of the neural crest and other vertebrate traits". Differentiation. 87 (1 ...
... is the biological discipline that consists of the study of Vertebrate animals, i.e., animals with a backbone ... In some cases whole museums bear this name, e.g. the Museum of Vertebrate Zoology at the University of California, Berkeley. ... Vertebrate Zoology at Wikipedia's sister projects Definitions from Wiktionary Media from Commons News from Wikinews Quotations ... Many natural history museums have departments named Vertebrate Zoology. ...
Many vertebrates have evolved limbless, limb-reduced, or apodous forms. Reptiles have on a number of occasions evolved into ... Larvae - which describes many non-vertebrate limbless forms Woltering, Joost M (2012). "From Lizard to Snake; Behind the ... CS1 French-language sources (fr), Articles with short description, Short description matches Wikidata, Vertebrate anatomy). ... but simply retained the form that vertebrates had before they evolved limbs. There are no known limbless species of mammal or ...
... known fossil vertebrate genera. Romer became the first president of the Society of Vertebrate Paleontology in 1940, alongside ... the 1988 text Vertebrate Paleontology and Evolution. Carroll was president of the Society of Vertebrate Paleontology in 1983. ... Vertebrate paleontology is the subfield of paleontology that seeks to discover, through the study of fossilized remains, the ... 2001). Analysis of vertebrate structure. New York: Wiley. p. 429. ISBN 0-471-29505-1.{{cite book}}: CS1 maint: multiple names: ...
The taxonomy of the vertebrates presented by John Zachary Young in The Life of Vertebrates (1962) is a system of classification ... The Life of Vertebrates. 2nd. ed. New York, Oxford University Press. Disponible at BHL. (Articles with short description, Short ...
Some early land vertebrates had more than one (up to three) os centrale per hand or foot (plural "(ossa) centralia"). Distals, ... The carpus (wrist) and tarsus (ankle) of land vertebrates primitively had three rows of carpal or tarsal bones. Often some of ...
Vertebrate Paleontology is an advanced textbook on vertebrate paleontology by Alfred Sherwood Romer, published by the ... The 1988 book Vertebrate Paleontology and Evolution by Robert L. Carroll is largely based on Romer's book. The book provides a ... The Vertebrate Body. 5th ed. Saunders, Philadelphia. (6th ed. 1985) Ryan, M.J. (5 November 2009). "Died This Day: Alfred ... Romer, A.S. (1966): Vertebrate Paleontology. University of Chicago Press, Chicago; 3rd edition ISBN 0-7167-1822-7 Smith, C.H. ( ...
The vertebrate mitochondrial code (translation table 2) is the genetic code found in the mitochondria of all vertebrata. AGA ... Mitochondrial genes in some vertebrates (including humans) have incomplete stop codons ending in U or UA, which become complete ... and AGG were thought to have become mitochondrial stop codons early in vertebrate evolution. However, at least in humans it has ...
While not vertebrate, brief mention is made here of the convergent evolution of vertebrate and Molluscan eyes. The most complex ... In the simplest vertebrates, the lampreys and hagfish, the lens is not attached to the outer surface of the eyeball at all. ... When considering vertebrates, aspects of all models may play varying roles in lens focus. The models can be broadly divided ... Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object ...
... s are a subclass of ciliary opsins and mediate vision in vertebrates. They include the opsins in human ... not deviating far from 500 nm in any vertebrate. Extant vertebrates typically have four cone opsin classes (LWS, SWS1, SWS2, ... While opsins can only bind retinal, there are two forms of retinal that can act as the chromophore for vertebrate visual opsins ... These five classes of vertebrate visual opsins emerged through a series of gene duplications beginning with LWS and ending with ...
The vertebrate land invasion refers to the transition of vertebrate animals from being aquatic/semiaquatic to predominantly ... The vertebrate species that were important to the initial water to land transition can be sorted into five phases: ... The late Devonian vertebrate transition was preceded by terrestrial invasion by fungi, land plants and invertebrates such as ... ISBN 978-0-253-35675-8. Ashley-Ross, M. A.; Hsieh, S. T.; Gibb, A. C.; Blob, R. W. (9 May 2013). "Vertebrate Land Invasions- ...
Vertebrate Palaeontology is a basic textbook on vertebrate paleontology by Michael J. Benton, published by Blackwell's. It has ... The book gives an overall account of every major group of living and fossil vertebrate. At the rear of the book is a ... his expertise in a range of problems of vertebrate paleontology is amazing. As a result the contents of his book [are] very ... Dzik, J. (2005). "Vertebrate Palaeontology (3rd ed.), by Michael J. Benton" (PDF). Journal of Sedimentary Research. Retrieved ...
While not vertebrate, brief mention is made here of the convergent evolution of vertebrate and Molluscan eyes. The most complex ... In land vertebrates the lens is flatter on its anterior side than on its posterior side, while in fish the lens is often close ... Some vertebrates need to see well both above and below water at times. One example is diving birds which have the ability to ... In the simplest vertebrates, the lampreys and hagfish, the lens is not attached to the outer surface of the eyeball at all. ...
The Vertebrate Genomes Project (VGP) is a project which aims to generate high-quality, complete reference genomes of all 66,000 ... "The Vertebrate Genomes Project at Rockefeller University". Rhie, Arang; McCarthy, Shane A.; Fedrigo, Olivier; et al. (April 29 ... doi:10.1186/s12915-022-01427-8. Vertebrate Genomes Project v t e (All stub articles, Scientific organization stubs, Genomics, ... "Researchers reboot ambitious effort to sequence all vertebrate genomes, but challenges loom". Science , AAAS. September 13, ...
"Vertebrate succession in the Ischigualasto Formation". Journal of Vertebrate Paleontology. 32: 10-30. Bibcode:2013JVPal..32S.. ... Land vertebrate faunachrons (LVFs) are biochronological units used to correlate and date terrestrial sediments and fossils ... Triassic tetrapod biozones, under the term "land vertebrate faunachrons" (LVFs) were formalized on a global level by Lucas in ... "Modeling the dynamics of a Late Triassic vertebrate extinction: The Adamanian/Revueltian faunal turnover, Petrified Forest ...
... - History. Museusm of Vertebrate Zoology - Collections. Science Today, radio program of University ... The Museum of Vertebrate Zoology is a natural history museum at the University of California, Berkeley. The museum was founded ... The museum became a center of authority for the study of vertebrate biology and evolution on the West Coast, comparable to ... Official website Media related to Museum of Vertebrate Zoology at Wikimedia Commons UC Berkeley Interactive Map - Museum is in ...
The Vertebrate Genome Annotation (VEGA) database was first made public in 2004 by the Wellcome Trust Sanger Institute. It was ... The human and vertebrate analysis and annotation (Havana) team at the Wellcome Trust Sanger Institute (WTSI) manually annotate ... The Vertebrate Genome Annotation (VEGA) database is a biological database dedicated to assisting researchers in locating ... The VEGA browser is based on Ensembl web code and infrastructure and provides a public curation of known vertebrate genes for ...
... is an advanced textbook on vertebrate paleontology by Robert L. Carroll, published in ... Vertebrate Paleontology and Evolution. WH Freeman and Company, New York ISBN 0-7167-1822-7 v t e v t e (Articles needing ... Vertebrate Paleontology and Evolution appeared in print in 1988, just before the cladistic taxonomy became popular in ... It provides a very detailed technical account of various groups of living and fossil vertebrates. The book, which is written in ...
"Society of Vertebrate Paleontology Awards". Society of Vertebrate Paleontology. Retrieved 22 July 2018. SVP's website SVP's ... "Society of Vertebrate Paleontology Advocacy". Society of Vertebrate Paleontology. Retrieved 22 July 2018. Underwood, Emily (6 ... The position of the SVP is that "The fossil record of vertebrates unequivocally supports the hypothesis that vertebrates have ... The Bibliography of Fossil Vertebrates is an index for publications on all subjects related to vertebrate paleontology. ...
It covers all aspects of vertebrate paleontology, including vertebrate origins, evolution, functional morphology, taxonomy, ... The Journal of Vertebrate Paleontology is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri ... "Journal of Vertebrate Paleontology". 2017 Journal Citation Reports. Web of Science (Science ed.). Clarivate Analytics. 2018. ... The journal is published by Taylor & Francis on behalf of the Society of Vertebrate Paleontology. According to Journal Citation ...
The Western Foundation of Vertebrate Zoology (WFVZ) is a non-profit charitable organization based in Camarillo, California ... the Proceedings of the Western Foundation of Vertebrate Zoology (ISSN 0511-7550).[citation needed] John R. Cruttenden WFVZ ...
Triumph of the Vertebrates is a 2013 British documentary film by David Attenborough. It is about the evolution of vertebrates. ... This episode goes through how the vertebrates evolved and came onto land. It details the origins of the vertebrates, which lie ... He reveals how vertebrates came to be the dominant form of animal life, and why humans are the heirs to a magnificent ... David Attenborough embarks on an epic 500-million-year journey to unravel the incredible rise of vertebrates. The evolution of ...
Functional vertebrate morphology, 210-229. Bramble, D. M., Liem, K. F., & Wake, D. B. (1985). Functional vertebrate morphology ... Limbs in vertebrates are occasionally organized into stylopod (relating to the humerus and femur), zeugopod (relating to the ... The main technique used in water is suction feeding and is used by most aquatic vertebrates. This technique does not function ... Iwasaki S. Evolution of the structure and function of the vertebrate tongue. J Anat. 2002 Jul;201(1):1-13. doi: 10.1046/j.1469- ...
... which in vertebrates, depending on the species, may include the ureter, urinary bladder, cloaca, and urethra. All vertebrates ... and in many vertebrates also produces hormones (in particular, renin) and maintains blood pressure. In healthy vertebrates, the ... and is also found in the embryos of some more developed vertebrates. In lower vertebrates, the pronephros is sometimes called ... replacing each other and reflecting the evolution of the kidneys in vertebrates. At the very beginning of vertebrates, when ...
Watch Classifying Vertebrates, Science Videos on TeacherTube. ...
Faroese terms for types or instances of vertebrates. NOTE: This is a set category. It should contain terms for vertebrates, not ... It may contain more general terms (e.g. types of vertebrates) or more specific terms (e.g. names of specific vertebrates), ... Fundamental » All languages » Faroese » All topics » Lifeforms » Animals » Chordates » Vertebrates ... Retrieved from "https://en.wiktionary.org/w/index.php?title=Category:fo:Vertebrates&oldid=67455986" ...
Vertebrate Paleontology Archives Contacts. Curator-in-Charge. Dr. Michael Novacek. [email protected] ... In Fall 2020 the Department of Vertebrate Paleontology was awarded a grant from the Institute of Museum and Library Services to ... and administrative paperwork associated with the Department of Vertebrate Paleontology. (Archival materials relating to ...
Lewis, R. S. & Hudspeth, A. J. Voltage- and ion-dependent conductances in solitary vertebrate hair cells. Nature 304, 538-541 ( ... Bellono, N., Leitch, D. & Julius, D. Molecular basis of ancestral vertebrate electroreception. Nature 543, 391-396 (2017). ... cloning and comparison across vertebrate classes. Brain Res. Mol. Brain Res. 109, 63-83 (2002) ...
... December 18, 2011. Marc Abrahams This charming logo was associated with the Fourteenth Vertebrate ... Arts and ScienceAlice, conference, logo, vertebrate pest Post navigation. Figure from a possibly-innovative neti pot patent ...
Vertebrates Home. Vertebrate Bones. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z. The Humerus Early Development. Note: ...
Neonicotinoids or neonics are insecticides that are toxic to vertebrates and invertebrates. In North Dakota, harvested wild ...
The first vertebrates on Earth arose in shallow coastal waters By Carolyn Gramling. October 25, 2018. ... The first land-walking vertebrates may have emerged from salty estuaries. An analysis casts doubt on views that the ancient ... Ancient fish fossils highlight the strangeness of our vertebrate ancestors By Carolyn Gramling. September 28, 2022. ... SALTY SCENE The planets earliest four-footed vertebrates called tetrapods (illustrated) lived in the brackish waters of an ...
Find out how to identify vertebrates in this article from HowStuffWorks. ... There are five classes of vertebrates. The easiest way to determine what class a vertebrate belongs to is by looking at the ... Vertebrates are animals with a backbone and an internal skeleton. Their skeleton consists of cartilage and bone, a skull with a ... Here is a list of the vertebrates classes and the different body coverings. ...
... Citation. Gyeltshen C, Prasad K (2021). Bhutan: Vertebrate species. National Biodiversity Centre. ... This specific dataset Bhutan: Vertebrate species provides a checklist of the 1146 vertebrate species, that is, mammals, birds ...
... Translated by Larry W. Swanson and Neely Swanson ... The book also presents in simplified form the ideas contained in Cajals famous survey of vertebrate neurohistology, Histologie ... the Nobel Prize in medicine in 1906.New Ideas on the Structure of the Nervous System in Man and Vertebrates presents the ...
Now researchers combing through the DNA sequences of vertebrate genomes have identified three distinct periods of evolutionary ... the vertebrate lineage branched out from a primitive jawless fish wriggling through Cambrian seas to encompass all the diverse ... which aims to get genome sequences for 10,000 vertebrate species. With such a large number vertebrate genome sequences ... 5, 2021 Lungs and limbs have been thought of as key innovations that came with the vertebrate transition from water to land. ...
Vertebrate Biology. Vertebrate Biology 2023-24. BSX-2022. 2023-24. School Of Natural Sciences. Module - Semester 1. 20 credits ... End Semester Vertebrate Biology exam including a selection of short essays covering all aspects of the module. ... This module traces the origins of vertebrates through a series of around 21 lectures (mostly face-to-face but with additional ... Demonstrate a conceptual understanding of the interaction of vertebrates with their environment. (Biosciences benchmarks: 3.2 ...
Whatcheeria was an early tetrapod - one of the first vertebrates to have arms and legs instead of fins. At 2 metres long, it ... A large, crocodile-like animal that lived more than 340 million years ago was one of the earliest vertebrates to have a fast- ... Ancient predator was one of first vertebrates to grow fast while young. The bones of 2-metre-long tetrapod Whatcheeria reveal ...
... and to assist in the biological understanding of a variety of biomedically and evolutionarily important vertebrate organisms. ... The main goal of the Vertebrate Biology Group is threefold: to aid in the annotation and basic understanding of both the ... The Vertebrate Biology Group approaches these goals in several ways, both by leveraging the vast amount of data generated from ... The Vertebrate Biology Group maintains a variety of collaborations, within the Broad Institute as well as with a large number ...
... the precursor to vertebrate jaws as we know them today, may be older than previously thought. ... The first vertebrates were jawless, but vertebrates now exhibit a variety of teeth and jaws that differ greatly across species ... Tracing the evolution of vertebrate teeth. The fossil skull of Radotina, one of the most primitive jawed vertebrates with teeth ... "Even though acanthothoracids are among the most primitive of all jawed vertebrates, their teeth are in some ways far more like ...
Vertebrate Animal Research. The University of Vermont (UVM) is committed to the humane care and use of animals in activities ...
Vertebrates are a subgroup of the chordates. Modern vertebrates include fish, sharks, mammals, and amphibians. ... All vertebrates have a backbone that surrounds and protects the nerve cord, a character that they all inherited from their ... vertebrate. vertebrate. Any member of the animal clade Vertebrata. All vertebrates have a backbone that surrounds and protects ... Vertebrates are a subgroup of the chordates. Modern vertebrates include fish, sharks, mammals, and amphibians. ...
... Laurent Duret duret at evoserv.univ-lyon1.fr Mon May 9 08:07:58 EST 1994 * ... HOVERGEN allows one to easily select sets of homologous genes among a given set of vertebrate species. HOVERGEN corresponds to ... HOVERGEN is a database of homologous vertebrate genes. ... all nuclear vertebrate sequences of GenBank, with some data ...
Alphonse Dubois, who was appointed curator of the vertebrate collections in 1869, was the first to describe many of De ...
Sold By: Vertebrate Publishing. * Peak District Mountain Biking: Dark Peak Trails Guide. £15.95. Sold By: Vertebrate Publishing ... Sold By: Vertebrate Publishing. * White Peak Mountain Biking The Pure Trails Second Edition. £15.95. Sold By: Vertebrate ... Sold By: Vertebrate Publishing. * South West Mountain Biking Quantocks, Exmoor, Dartmoor. £15.95. Sold By: Vertebrate ... Sold By: Vertebrate Publishing. * Gravel Rides Scotland 28 gravel bike adventures in the wilds of Scotland. £25.00. Sold By: ...
... as is the case for higher vertebrates. In addition, the level of sensitivity to form deprivation is weight dependent. ... a lower vertebrate species, exhibits positive and negative lens-induced refractive change, ... Eyes of a lower vertebrate are susceptible to the visual environment Invest Ophthalmol Vis Sci. 2007 Oct;48(10):4829-37. doi: ... Conclusions: Tilapia, a lower vertebrate species, exhibits positive and negative lens-induced refractive change, as is the case ...
... To view these resources with no ads, please Login or Subscribe to help support our ... Vertebrates (Class Chordata) Diagram Exploring Nature Educational Resource ©2005-2023. September 30, 2023. , http://www. ...
The emergence of gnathostomes [a superclass of the above-mentioned vertebrates] from jawless vertebrates marks a major event in ... Vertebrates have no deep evolutionary past. The article addresses the threat to the worlds animals-a valid concern-but ... Amen."9 One does not have to bring up unknown and unobserved vertebrate evolution and its extreme ages in order to exercise ... Human activity threatens vertebrate evolutionary history. ScienceDaily. Posted on sciencedaily.com June 3, 2020, accessed June ...
Rabbit anti-Vertebrates, Mouse, Clone: 2N8, MilliporeSigma™ at Fishersci.com ...
Amy Henrici is Collection Manager in the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum ... Matt Lamanna is Mary R. Dawson Associate Curator and Head of the Section of Vertebrate Paleontology at Carnegie Museum of ... Amy Henrici is Collection Manager in the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum ... Lindsay Kastroll is a volunteer and paleontology student working in the Section of Vertebrate Paleontology at Carnegie Museum ...
This Special Issue will contain papers that focus on the variability and evolution of early vertebrates, especially for taxa ... vertebrate clades, focusing on methodologies such as morphometrics, stratigraphic and/or comparative analyses, as well as ... ontogenetic and evolutionary variability in a wide range of vertebrate taxa, which can be reproduced in future contributions. ... Taxonomic Variability 2022 : Taxonomic Variability and Morphometrics in Early Vertebrates Link: https://peerj.com/special- ...
  • The main goal of the Vertebrate Biology Group is threefold: to aid in the annotation and basic understanding of both the structure and function of the human genome (see 29 Mammals Project ), to further inform our understanding of adaptive evolution in all its forms, and to assist in the biological understanding of a variety of biomedically and evolutionarily important vertebrate organisms. (broadinstitute.org)
  • This specific dataset 'Bhutan: Vertebrate species' provides a checklist of the 1146 vertebrate species, that is, mammals, birds, reptiles, amphibians and fishes from the Animalia Kingdom that are found across Bhutan. (gbif.org)
  • Over the past 530 million years, the vertebrate lineage branched out from a primitive jawless fish wriggling through Cambrian seas to encompass all the diverse forms of fish, birds, reptiles, amphibians, and mammals. (sciencedaily.com)
  • New regulatory elements affecting transcription factors peaked in our early vertebrate ancestors 500 million years ago, then declined steadily to background levels by the time mammals evolved. (sciencedaily.com)
  • A recent article speaks of "the evolutionary history of the world's terrestrial vertebrates: amphibians, birds, mammals and reptiles" and how the "evolutionarily distinct species" of today are supposedly being obstructed by the "human footprint. (icr.org)
  • In this review, we will look at the current state of understanding of PLCζ's mechanism of action and physiological role in mammals and other vertebrates, and identify areas of uncertainty that still remain to be resolved. (umass.edu)
  • Researchers used species data for most land-vertebrate species (33,548 amphibians, birds, mammals, and reptiles) on recent exposure to maximum temperatures to predict the impacts of upcoming extreme temperatures by the end of the 21st century. (azocleantech.com)
  • In mammals and many higher vertebrates, each muscle fiber typically has a single synaptic site innervated by a single motor axon branch. (intechopen.com)
  • When the blood is being filtered, the kidneys form urine, which consists of water and excess or unnecessary substances, the urine is then excreted from the body through other organs, which in vertebrates, depending on the species, may include the ureter, urinary bladder, cloaca, and urethra. (wikipedia.org)
  • In some vertebrate species, the pronephros and mesonephros are functional organs, while in others they are only intermediate stages in the development of the final kidney, and each next kidney replaces the previous one. (wikipedia.org)
  • Here we use extensive species-level data in a time-to-event model framework to identify taxonomic and geographic discovery gaps in terrestrial vertebrates. (nature.com)
  • The first vertebrates were jawless, but vertebrates now exhibit a variety of teeth and jaws that differ greatly across species in form and function. (cosmosmagazine.com)
  • HOVERGEN allows one to easily select sets of homologous genes among a given set of vertebrate species. (bio.net)
  • Tilapia, a lower vertebrate species, exhibits positive and negative lens-induced refractive change, as is the case for higher vertebrates. (nih.gov)
  • We also found that by 2099 in this scenario, 3,773 species, or 11% of total land vertebrates are likely to face extreme thermal events during most of the year. (azocleantech.com)
  • Invasive vertebrate species impact our environment, economy and society. (mdpi.com)
  • We find that at least 412 ERVi elements representing 217 viral operational taxonomic units are invading the genomes of 123 vertebrates , 18 of which have been assessed to be threatened species . (bvsalud.org)
  • Most of the changes that have happened during vertebrate evolution, as animals acquired new body plans and features like feathers and hair, were not the result of new genes but of new regulatory elements that turn genes on and off in different patterns," Haussler said. (sciencedaily.com)
  • The Division of Paleontology houses an extensive archive of correspondence, field journals, maps, illustrations, and administrative paperwork associated with the Department of Vertebrate Paleontology. (amnh.org)
  • In Fall 2020 the Department of Vertebrate Paleontology was awarded a grant from the Institute of Museum and Library Services to improve access to the department's archives. (amnh.org)
  • The Bibliography of Fossil Vertebrates (BFV) aimed to index the world literature of vertebrate paleontology. (vertpaleo.org)
  • However, this volume continued the work begun by O. P. Hay and his colleagues, who had published two previous retrospective volumes covering the literature of North American vertebrate paleontology, in 1902 and 1929. (vertpaleo.org)
  • Thus, for approximately one hundred years the vertebrate paleontology research community has compiled and indexed its own widely dispersed, specialized literature. (vertpaleo.org)
  • As with other efforts to map human threats across all land vertebrates, we show that amphibians and reptiles are much more at risk. (azocleantech.com)
  • The BFV Online provides interactive access to the SVP's Bibliography of Fossil Vertebrates series. (vertpaleo.org)
  • The Bibliography of Fossil Vertebrates was compiled and published as a series of volumes, beginning with the 1928-1933 Camp, et al. (vertpaleo.org)
  • All of these volumes are generally considered part of the Bibliography of Fossil Vertebrates series, which thus includes an unbroken record of the entire published literature on vertebrate fossils, starting at the year 1509. (vertpaleo.org)
  • 1962. Bibliography of Fossil Vertebrates Exclusive of North America. (vertpaleo.org)
  • 1940. Bibliography of Fossil Vertebrates 1928-1933. (vertpaleo.org)
  • The Vertebrate Biology Group approaches these goals in several ways, both by leveraging the vast amount of data generated from the large number of vertebrate genomes sequenced to date (both at the Broad Institute and elsewhere) and by the coordination of new vertebrate genome sequencing projects. (broadinstitute.org)
  • Now researchers combing through the DNA sequences of vertebrate genomes have identified three distinct periods of evolutionary innovation that accompanied this remarkable diversification. (sciencedaily.com)
  • Genome mining shows that retroviruses are pervasively invading vertebrate genomes. (bvsalud.org)
  • However, the vast majority of ERVs are not active anymore due to various disruptive mutations , and ongoing retroviral invasion of vertebrate genomes has been rarely documented. (bvsalud.org)
  • Using synchrotron microtomography, a team of Swedish, Czech, French and UK researchers led by Sweden's Uppsala University took a detailed look at a collection of 400-million-year-old fossils of acanthothoracids - an early fish group closely related to the very first jawed vertebrates - found near the Prague Basin in the Czech Republic a century ago. (cosmosmagazine.com)
  • Although no compilation can ever be complete, the BFV attempted to include every published scientific work that mentioned vertebrate fossils. (vertpaleo.org)
  • an invaluable aid to those who wish to know more about vertebrate fossils. (nhbs.com)
  • It is believed that the development of embryonic kidneys reflects the evolution of vertebrate kidneys from an early primitive kidney, the archinephros. (wikipedia.org)
  • The kidneys of amniotes are unique compared to other internal organs, since three different kidneys are sequentially developed during embryogenesis, replacing each other and reflecting the evolution of the kidneys in vertebrates. (wikipedia.org)
  • At the very beginning of vertebrates, when they evolved from marine chordates, their evolution probably took place in fresh or slightly saline water. (wikipedia.org)
  • The mesonephros probably appeared in the course of evolution in response to the increase in body mass of vertebrates, which also led to an increase in blood pressure. (wikipedia.org)
  • The evolution of the kidneys, along with the evolution of the lungs, allowed vertebrates called amniotes to live and reproduce in terrestrial environment. (wikipedia.org)
  • This module traces the origins of vertebrates through a series of around 21 lectures (mostly face-to-face but with additional online video resources) and follows the subsequent major advances in the evolution of aquatic, terrestrial and aerial groups. (bangor.ac.uk)
  • Written answers should try and synthesise key aspects of the lecture material and enclosed information, and demonstrate an attempt to integrate and evaluate the principles underlying the structural evolution and function of vertebrates. (bangor.ac.uk)
  • Demonstrate a conceptual understanding of processes of evolution, phylogeny, physiology and biomechanics of vertebrates. (bangor.ac.uk)
  • They found three broad categories of evolutionary innovations in gene regulation that increased in frequency during different periods in vertebrate evolution. (sciencedaily.com)
  • The findings also provide the first indication of distinct phases in vertebrate molecular evolution, with changes in different types of biological processes dominating during different periods of evolutionary history. (sciencedaily.com)
  • The emergence of gnathostomes [a superclass of the above-mentioned vertebrates] from jawless vertebrates marks a major event in the evolution of vertebrates. (icr.org)
  • The article addresses the threat to the world's animals-a valid concern-but corrupts the issue unnecessarily with the unobserved process of vertebrate evolution and deep evolutionary time. (icr.org)
  • 9 One does not have to bring up unknown and unobserved vertebrate evolution and its extreme ages in order to exercise care for the created environment and the animals it contains. (icr.org)
  • Vertebrates: Comparative Anatomy, Function & Evolution , 6th ed. (icr.org)
  • This Special Issue will contain papers that focus on the variability and evolution of early vertebrates, especially for taxa that are well-represented in the fossil record but include specimens that are poorly preserved, which hampers definition of diagnostic characters. (wikicfp.com)
  • Vertebrate Palaeontology is a complete, up-to-date history of the evolution of vertebrates. (nhbs.com)
  • Strong phylogenetic focus making it an up-to-date source of the latest broad-scale systematic data on vertebrate evolution. (nhbs.com)
  • By developing a unified, multi-scale model of somitogenesis -- a process that establishes the earliest evident segmentation in vertebrate embryos -- both a case study for other scientists creating similar predictive, informative multi-scale models of development and important insights into the vertebrate body plan and its evolution have been achieved, according to Biocomplexity Institute Director James Glazier. (phys.org)
  • Fig. 3: Predicted future discovery potential across major terrestrial vertebrate taxa. (nature.com)
  • This Special Issue will be among the first compilations of novel data for determining the presence and origin of morphological, ontogenetic and evolutionary variability in a wide range of vertebrate taxa, which can be reproduced in future contributions. (wikicfp.com)
  • Vertebrates are a subgroup of the chordates . (berkeley.edu)
  • Faced with these intrinsic obstacles and with little evidence from the fossil record to help, it is hardly surprising that disagreement over the origin of chordates [a large phylum containing all vertebrates] has been common. (icr.org)
  • Evolutionary pressure and the need to regulate body fluid homeostasis have led to pre-adaptation of the vertebrate kidneys to different environment conditions and to development of three kidney forms: the pronephros, mesonephros and metanephros. (wikipedia.org)
  • threshold (D) -A threshold student should have a basic knowledge of some of the essential facts and key concepts of the evolutionary history, anatomical structure and diversity of vertebrates presented in the module. (bangor.ac.uk)
  • The evolutionary roots of teeth and dermal jawbones (cheekbones), the precursor to vertebrate jaws as we know them today, may be older than previously thought. (cosmosmagazine.com)
  • But humans are being blamed by secular scientists for threatening-of all things-vertebrate evolutionary history! (icr.org)
  • 3 Ironically, there is nothing known for sure about the alleged evolutionary history of vertebrates-they have always been distinct from other life forms. (icr.org)
  • Vertebrates have no deep evolutionary past. (icr.org)
  • Neonicotinoids or neonics are insecticides that are toxic to vertebrates and invertebrates. (organicconsumers.org)
  • Invertebrates are the name of all other animals that do not belong to the insects or vertebrates. (lu.se)
  • Our results reveal an unexpected prevalence of ongoing retroviral invasion in vertebrates and expand the diversity of retroviruses recently circulating in the wild. (bvsalud.org)
  • Title : Feeding Period Required by Amblyomma aureolatum Ticks for Transmission of Rickettsia rickettsii to Vertebrate Hosts Personal Author(s) : Saraiva, Danilo G.;Soares, Herbert S.;Soares, João Fábio;Labruna, Marcelo B. (cdc.gov)
  • [ 1 ] Arboviruses are maintained in transmission cycles between arthropods and vertebrate hosts, including humans and other animals. (medscape.com)
  • Leishmania promastigotes are transmitted by sand flies ( Phlebotomus , Lutzomyia ) to vertebrate hosts. (msdmanuals.com)
  • We encourage submissions of primary research papers, especially those on the taxonomic variability in ancient (Paleozoic and Mesozoic) vertebrate clades, focusing on methodologies such as morphometrics, stratigraphic and/or comparative analyses, as well as taxonomic revisions or redescriptions. (wikicfp.com)
  • Even though acanthothoracids are among the most primitive of all jawed vertebrates, their teeth are in some ways far more like modern ones than arthrodire dentitions. (cosmosmagazine.com)
  • HOVERGEN corresponds to all nuclear vertebrate sequences of GenBank, with some data corrected, clarified, or completed, notably to address the problem of redundancy. (bio.net)
  • End Semester Vertebrate Biology exam including a selection of short essays covering all aspects of the module. (bangor.ac.uk)
  • The Vertebrate Biology Group maintains a variety of collaborations, within the Broad Institute as well as with a large number of outside research communities. (broadinstitute.org)
  • For years people cited the wiring of the vertebrate eye as evidence of "poor design" in biology. (evolutionnews.org)
  • SALTY SCENE The planet's earliest four-footed vertebrates called tetrapods (illustrated) lived in the brackish waters of an estuary or delta, new research suggests. (sciencenews.org)
  • Earth's earliest land-walking vertebrates didn't paddle about in freshwater lakes or rivers. (sciencenews.org)
  • A large, crocodile-like animal that lived more than 340 million years ago was one of the earliest vertebrates to have a fast-growing phase in its youth. (newscientist.com)
  • Vertebrates are animals with a backbone and an internal skeleton. (howstuffworks.com)
  • All vertebrates have a backbone that surrounds and protects the nerve cord, a character that they all inherited from their common ancestor . (berkeley.edu)
  • After the well-received 2022 collection , Frontiers in Microbiology is proud to host this Research Topic celebrating women's work and achievements in the field of Microorganisms in Vertebrate Digestive Systems. (frontiersin.org)
  • Fig. 1: Variation in observed and predicted discovery trends for the years 1759-2014 across the four terrestrial vertebrate groups. (nature.com)
  • Fig. 4: Global variation in predicted discovery potential, quantified as the percent of all global terrestrial vertebrate discoveries predicted to occur in a region. (nature.com)
  • Best vertebrate pest logo? (improbable.com)
  • This charming logo was associated with the Fourteenth Vertebrate Pest Conference , which was held in 1990. (improbable.com)
  • Eric worked for Horizons over a span of almost 40 years and through his experience at Horizons and his roles prior to joining Horizons, he really became a leading subject matter expert in vertebrate pest management. (voxy.co.nz)
  • The kidney is a paired organ of the excretory system in vertebrates, which maintains the balance of water and electrolytes in the body (osmoregulation), filters the blood, removes metabolic waste products, and in many vertebrates also produces hormones (in particular, renin) and maintains blood pressure. (wikipedia.org)
  • Here is a list of the vertebrates' classes and the different body coverings. (howstuffworks.com)
  • ANNOUNCEMENT ================================================================================ HOVERGEN Homologous Vertebrate Genes Data Base Release 6 (May 9 1994) from GenBank Release 82 (April 15 1994) ================================================================================ The new release is available by anonymous FTP at biom3.univ-lyon1.fr (134.214.100.42) in the directory /pub/hovergen HOVERGEN is a database of homologous vertebrate genes. (bio.net)
  • Here we analyze genomics data from 2004 vertebrates for mining invading ERVs (ERVi). (bvsalud.org)
  • As a result, early vertebrates developed renal glomeruli capable of filtering blood and perhaps tubules that reabsorbed ions. (wikipedia.org)
  • Whatcheeria was an early tetrapod - one of the first vertebrates to have arms and legs instead of fins. (newscientist.com)
  • This discovery shows it is the longest living vertebrate known to science, exceeding even bowhead whales, turtles and tortoises. (earthscape.org)
  • My latest research concerns the eyes of vertebrates, and here we now have new information that clearly points to the fact that we lost our original paired eyes more than 500 million years ago before we became vertebrates, and that new eyes evolved from an unpaired median eye (which still lives on as our pineal gland in the brain). (lu.se)
  • How these novelties emerged and how they facilitated the divergence, adaptation and dominance of gnathostomes as the major group (99.9%) of living vertebrates are key unresolved questions. (icr.org)
  • In healthy vertebrates, the kidneys maintain homeostasis of extracellular fluid in the body. (wikipedia.org)
  • The easiest way to determine what class a vertebrate belongs to is by looking at the body covering. (howstuffworks.com)
  • Demonstrate a conceptual understanding of the interaction of vertebrates with their environment. (bangor.ac.uk)
  • The book also presents in simplified form the ideas contained in Cajal's famous survey of vertebrate neurohistology, Histologie du Systeme Nerveux de l'Homme et des Vertébrés, unquestionably the most important book ever published in neuroanatomy, and which to this day has not been translated and published in English because of its extraordinary length. (mit.edu)