• The sex is principally determined by genotype in all species, but the mechanisms range from a single controlling locus to sex chromosomes bearing several linked loci required for sex determination. (researchgate.net)
  • Across species, different sexes are often characterized by different types and numbers of sex chromosomes. (wikipedia.org)
  • In order to neutralize the large difference in gene dosage produced by differing numbers of sex chromosomes among the sexes, various evolutionary branches have acquired various methods to equalize gene expression among the sexes. (wikipedia.org)
  • Because sex chromosomes contain different numbers of genes, different species of organisms have developed different mechanisms to cope with this inequality. (wikipedia.org)
  • Different lineages have evolved different mechanisms to cope with the differences in gene copy numbers between the sexes that are observed on sex chromosomes. (wikipedia.org)
  • One logical way to equalize gene expression amongst males and females that follow a XX/XY sex differentiation scheme would be to decrease or altogether eliminate the expression of one of the X chromosomes in an XX, or female, homogametic individual, such that both males and females then express only one X chromosome. (wikipedia.org)
  • The sex of many organisms is determined by the number of X chromosomes. (mpg.de)
  • Contrary to classic theory prediction, sex-chromosome homomorphy is prevalent in the animal kingdom but it is unclear how ancient homomorphic sex chromosomes avoid chromosome-scale degeneration. (nature.com)
  • Molluscs constitute the second largest, Precambrian-originated animal phylum and have ancient, uncharacterized homomorphic sex chromosomes. (nature.com)
  • Here, we profile eight genomes of the bivalve mollusc family of Pectinidae in a phylogenetic context and show 350 million years sex-chromosome homomorphy, which is the oldest known sex-chromosome homomorphy in the animal kingdom, far exceeding the ages of well-known heteromorphic sex chromosomes such as 130-200 million years in mammals, birds and flies. (nature.com)
  • The long-term undifferentiation of molluscan sex chromosomes is potentially sustained by the unexpected intertwined regulation of reversible sex-biased genes, together with the lack of sexual dimorphism and occasional sex chromosome turnover. (nature.com)
  • The pleiotropic constraint of regulation of reversible sex-biased genes is widely present in ancient homomorphic sex chromosomes and might be resolved in heteromorphic sex chromosomes through gene duplication followed by subfunctionalization. (nature.com)
  • The evolutionary dynamics of sex chromosomes suggest a mechanism for 'inheritance' turnover of sex-determining genes that is mediated by translocation of a sex-determining enhancer. (nature.com)
  • On the basis of these findings, we propose an evolutionary model for the long-term preservation of homomorphic sex chromosomes. (nature.com)
  • Fig. 1: Phylogeny-scale profiling of scallop sexual systems and sex chromosomes. (nature.com)
  • Fig. 3: Turnover and macroevolution of scallop sex chromosomes. (nature.com)
  • Charlesworth, B. The evolution of sex chromosomes. (nature.com)
  • Jablonka, E. & Lamb, M. J. The evolution of heteromorphic sex chromosomes. (nature.com)
  • Daish, T. & Grützner, F. Evolution and meiotic organization of heteromorphic sex chromosomes. (nature.com)
  • Understanding how neutrophil activity differs between sexes could be key to addressing many health issues in a more targeted way, the researchers said. (usc.edu)
  • The present study included 60 individuals ranging from 20-50 age group of both the sexes to observe the morphology of sex chromatin in neutrophil by using Leishman's and Field stain for the gender determination and comparison between the 2 staining procedure, using research microscope. (ijmhr.org)
  • Davidson W.M, Smith D.R. A morphological sex difference in the polymorphonuclear neutrophil leucocytes. (ijmhr.org)
  • Briggs D.K. The individuality of nuclear chromatin with particular reference to polymorphonuclear neutrophil leukocytes. (ijmhr.org)
  • Thus, human females have the same number of expressed X-linked genes per cell as do human males (XY), both sexes having essentially one X chromosome per cell, from which to transcribe and express genes. (wikipedia.org)
  • Some lineages have evolved dosage compensation, an epigenetic mechanism which restores expression of X or Z specific genes in the heterogametic sex to the same levels observed in the ancestor prior to the evolution of the sex chromosome. (wikipedia.org)
  • Fig. 2: Discovery of oldest known, 350 Myr sex-chromosome homomorphy in scallop. (nature.com)
  • Fig. 5: Divergence of sex chromosome and rSBG duplication across animal groups. (nature.com)
  • Fig. 6: Evolutionary model for homomorphy maintenance and heteromorphy transition of sex chromosome. (nature.com)
  • For example, important differences between sexes were evidenced in respect of palisadic tissue, epidermal stomatic number, secretory hair distribution etc. (researchgate.net)
  • A new data set collected by USC Leonard Davis School of Gerontology researchers provides an important new resource for studying differences in immune system function by age and sex. (usc.edu)
  • The data set that we generated allows us to look at different subpopulations of neutrophils, which will allow us to get a better insight on the sex differences that we have already described in bulk analysis," said Min Hoo Kim, postdoctoral fellow in the Benayoun lab and the study's first author. (usc.edu)
  • Previous research has shown that in mammals, the immune system displays widespread sex dimorphism, or differences between males and females, including how males are generally more susceptible to and have worse outcomes for severe infections, while females are more prone to autoimmune diseases. (usc.edu)
  • Benayoun and Kim are optimistic that their data will provide a valuable resource for other scientists to explore the underlying mechanisms behind sex differences in immune responses and examine the possibility of tailoring treatments based on sex-related immune characteristics. (usc.edu)
  • Whether these sex-based differences have biologic relevance that may translate into effects on health outcomes is unknown. (cdc.gov)
  • Dosage compensation is the process by which organisms equalize the expression of genes between members of different biological sexes. (wikipedia.org)
  • Most organisms have developed a strategy for making sure that the X chromosomal genes, which are important for both sexes, are properly transcribed. (mpg.de)
  • However, how exactly this change in the chromatin structure facilitates the expression of X chromosomal genes by just a factor of two remains poorly understood. (mpg.de)
  • In this system gene expression of sex-specific loci is reduced in the heterogametic sex i.e. the females in ZZ/ZW systems and males in XX/XY systems. (wikipedia.org)
  • Cutting-edge RNA study of neutrophils at the single-cell provides vital groundwork for further investigation of how immunity differs based on sex. (usc.edu)
  • However, the relationship between 25(OH)D and individual biomarkers of cardiometabolic disease has not been explored in the Canadian population, and whether it differs by sex is unknown. (cdc.gov)
  • Because the species with male individuals and female individuals have evolved repeatedly from hermaphroditic progenitors, the mechanisms for the control of sex determination in flowering plants are extremely diverse. (researchgate.net)
  • A sex chromatin study should be performed to exclude Klinefelter syndrome when appropriate. (medscape.com)
  • In addition, it highlights the need for the scientific community to more thoroughly include sex as a research variable and make sure study populations reflect the real world, Benayoun said. (usc.edu)
  • A Study of Sex Cheromatin Form Buccal Smear. (ijmhr.org)
  • We conducted linear regressions analyses (adjusted for sex, waist circumference, physical activity, hormone use, and season) to assess the relationship between 25-hydroxyvitamin D and biomarkers of dysglycemia, dyslipidemia, and inflammation in the study population. (cdc.gov)
  • The possibility that the effects of vitamin D on cardiometabolic disease differ by sex warrants further study. (cdc.gov)
  • Cannabis sativa L. is one of the best studied species under the aspect of genetic determinism of the sex, but the problem is not yet entirely deciphered. (researchgate.net)
  • In breeding activity, the early establishment of the sex would be necessary, imposed by the necessity to remove, from agronomic reasons, the male plants or the high masculinized monoecious plants. (researchgate.net)
  • Despite it being known that the biological differences between sexes become evident early in embryogenesis, the processes involved in these sex differences are not completely known [ 9 ] . (encyclopedia.pub)
  • Recent studies in non-mammalian model organisms have reported sex-biased expression at stages in which visible phenotypic differences between the sexes have not yet become apparent [ 17 ]. (springer.com)
  • In most mammalian cell lines, chromatin located at the nuclear periphery is represented by condensed heterochromatin, as evidenced by microscopy observations and DamID mapping of lamina-associated domains (LADs) enriched in dimethylated Lys9 of histone H3 (H3K9me2). (biomedcentral.com)
  • The Platypus lacks the mammalian sex-determining gene SRY , meaning that the process of sex determination in the Platypus remains unknown. (wikidoc.org)
  • Upon differentiation of ES cells to cardiac precursors, we found sex-biased expression of key transcription and epigenetic factors, some of which persisted from the undifferentiated state. (springer.com)
  • Our study reveals sex-biased histone modifications, underscoring the potential for the sex chromosome complement to prime the genome differently in early development with consequences for later expression biases. (springer.com)
  • During meiosis, the X chromosome in both sexes exhibits a striking reduction of histone modifications that correlate with transcriptional activation when compared with the genome as a whole. (biologists.com)
  • The X chromosome in XO males is structurally analogous to the sex body in mammals, contains a histone modification associated with heterochromatin in other species and is inactivated throughout meiosis. (biologists.com)
  • Previous research has shown that in mammals, the immune system displays widespread sex dimorphism, or differences between males and females, including how males are generally more susceptible to and have worse outcomes for severe infections, while females are more prone to autoimmune diseases. (usc.edu)
  • The XX/XY sex-determination system is one of the most familiar sex-determination systems and is found in human beings and most other mammals . (wikidoc.org)
  • The placenta is a temporary and sex-specific endocrine organ that regulates maternal-fetal exchanges, with a central role in fetal growth and development. (encyclopedia.pub)
  • Dosage compensation is the process by which organisms equalize the expression of genes between members of different biological sexes. (wikipedia.org)
  • These imbalances have not been explained at either the genetic or developmental level and indicate that sex is an important biological variable during early embryogenesis. (springer.com)
  • A sex-determination system is a biological system that determines the development of sexual characteristics in an organism . (wikidoc.org)
  • Cutting-edge RNA study of neutrophils at the single-cell provides vital groundwork for further investigation of how immunity differs based on sex. (usc.edu)
  • Building upon their previous studies of how aging affects immunity, a team led by scientists at The Jackson Laboratory, Farmington, Connecticut, looked deeper into the underlying molecular and genetic mechanisms behind sex differences in immunity at different stages of life. (nih.gov)
  • Germline maintenance in the nematode C. elegans requires global repressive mechanisms that involve chromatin organization. (biologists.com)
  • Benayoun and Kim are optimistic that their data will provide a valuable resource for other scientists to explore the underlying mechanisms behind sex differences in immune responses and examine the possibility of tailoring treatments based on sex-related immune characteristics. (usc.edu)
  • We surveyed the sex-specific landscape in early embryogenesis with special reference to cardiac development. (springer.com)
  • In fact, sex-specific expression differences in early embryogenesis are widespread across the animal kingdom. (springer.com)
  • Both sexes experienced alterations in the frequency and activity of different immune cell types with age such as declines in various types of white blood cells, including T cells (named because they mature in the thymus gland), monocytes (formed in the bone marrow), and cytotoxic cells (which kill damaged, infected, or cancerous cells). (nih.gov)
  • In this system gene expression of sex-specific loci is reduced in the heterogametic sex i.e. the females in ZZ/ZW systems and males in XX/XY systems. (wikipedia.org)
  • In this work, we investigated the role of Prdm14 in establishing sex-specific gene expression networks. (springer.com)
  • We generated sex-specific co-expression networks from mouse ES cells, examined the presence of sex-specific chromatin domains, and analyzed previously published datasets from different developmental time points to characterize how sex-biased gene expression waxes and wanes to evaluate whether sex-biased networks are detectable throughout heart development. (springer.com)
  • Generally, there has been no expectation in the developmental field that sex is relevant to early embryonic processes. (springer.com)
  • While studies of male and female differences have traditionally focused on the influence of sex hormones, these do not account for all the differences at the molecular and epigenetic levels. (springer.com)
  • To determine whether sex-biased expression is present throughout cardiogenesis, we re-analyzed data from two published studies that sampled the transcriptomes of mouse hearts from 8.5 days post-coitum embryos to neonates and adults. (springer.com)
  • One major issue is to comprehend, particularly in regard to behavior, factors which are important influences on sexual expression and the development of sex differences. (hawaii.edu)
  • Santangelo, C. Sex-specific ncRNAs Expression in Placenta. (encyclopedia.pub)
  • Sex-specific ncRNAs Expression in Placenta" Encyclopedia , https://encyclopedia.pub/entry/15752 (accessed December 01, 2023). (encyclopedia.pub)
  • Silencing of the sex chromosome during early meiosis is a conserved feature throughout the nematode phylum, and is not limited to hermaphroditic species. (biologists.com)
  • Other species, such as some snails, practice sex change: adults start out male, then become female. (wikidoc.org)
  • A new data set collected by USC Leonard Davis School of Gerontology researchers provides an important new resource for studying differences in immune system function by age and sex. (usc.edu)
  • But the role of sex in immune system aging is not well understood. (nih.gov)
  • The team studied shifts in immune system patterns over different life stages and found two distinct periods of rapid genomic change: one occurring in the late 30s to early 40s was found in both sexes, and another that occurred later in life that was found to be different between the sexes. (nih.gov)
  • These findings regarding how and when immune system changes differ by men and women could be potentially useful to help better customize clinical care based on sex and life stage, the researchers reported. (nih.gov)
  • The details of some sex-determination systems are not yet fully understood. (wikidoc.org)
  • The ZW sex-determination system is found in birds and some insects and other organisms . (wikidoc.org)
  • Women showed little age-related changes in B cells, but older men's B cells showed a major loss in chromatin accessibility, which relates to how DNA strands are wound and organized, indicating a decline in the B-cell function. (nih.gov)
  • In other cases, sex is determined by environmental variables (such as temperature ) or social variables (the size of an organism relative to other members of its population ). (wikidoc.org)