Genomic composition of old Y chromosomes. Old Y chromosomes, such as those of D. melanogaster and human, are often highly heterochromatic and have a large amount of repetitive and ampliconic DNA 15, making them notoriously difficult to sequence 12.The genes carried by the sex chromosomes of humans and other mammals overlap, suggesting that they all evolved from a common ancestral chromosome ... Background. The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome. Here, we developed a RAD-based approach to estimate neutral genetic diversity on sex chromosomes in relation to that on autosomes (R Z:A) for non-model avian species. We used this framework to test the association between sex-linked genomic variation and avian plumage dichromatism, a widely used surrogate for sexual selection.
Here, we investigated sex chromosome evolution in a phylogeographically complex species, the haplochromine cichlid P. philander (Egger et al. 2015). We detected an XX–XY system in the Lake Chila P. philander population, whereas this signature was not detectable in the genomes of an adjacent riverine stock. Abstract. Since the two eutherian sex chromosomes diverged from an ancestral autosomal pair, the X has remained relatively gene-rich, while the Y has lost most of its genes through the accumulation of deleterious mutations in nonrecombining regions.
Genomic analysis of 11 songbird species reveals evolutionary strata and shows their role in reshaping the genomic architecture of songbird sex chromosomes. Songbirds are a species-rich group known ... Sex determination in papaya is controlled by a recently evolved XY chromosome pair, with two slightly different Y chromosomes controlling the development of males (Y) and hermaphrodites (Yh). To study the events of early sex chromosome evolution, we sequenced the hermaphrodite-specific region of the Yh chromosome (HSY) and its X counterpart, yielding an 8.1-megabase (Mb) HSY pseudomolecule ... By database analysis and screening of an NT2/D1 uninduced male teratocarcinoma cell cDNA library, Gianfrancesco et al. (2001) cloned human DHRSX. The deduced 330-amino acid protein belongs to the SDR family and contains a coenzyme-binding site and a substrate-binding site.
Genomics is an interdisciplinary field of biology focusing on the structure, function, evolution, mapping, and editing of genomes.A genome is an organism's complete set of DNA, including all of its genes.In contrast to genetics, which refers to the study of individual genes and their roles in inheritance, genomics aims at the collective characterization and quantification of all of an organism ... A Brief History of Genomic Diagnosis: From Chromosome to DNA Array. Clin Pediatri. 2018; 1: 1002. Abstract. In Pediatric practice, chromosome analysis is often performed. This is because it is essential to diagnose chromosomal abnormalities such as Down syndrome.
The Y chromosome is one of two sex chromosomes in mammals, including humans, and many other animals.The other is the X chromosome.Y is normally the sex-determining chromosome in many species, since it is the presence or absence of Y that typically determines the male or female sex of offspring produced in sexual reproduction.In mammals, the Y chromosome contains the gene SRY, which by default ... In gaia: GAIA: An R package for genomic analysis of significant chromosomal aberrations.. Description Usage Arguments Value Author(s) Examples. Description. This function loads the markers contained within the matrix passed as argument and creates for all chromosomes an ordered vector containing the position of each marker.These vectors are loaded within a list.
Although most plants have both male and female organs within a single flower, some produce separate male and female plants. In some cases, such as persimmons, males are determined by a Y chromosome. Akagi et al. examined the gene transcript differences between male and female persimmons. A gene on the Y chromosome regulated a non–sex chromosome–linked small RNA that suppresses female organ ... Comparative genomics of sex chromosomes in Diptera: gene trafficking, dosage compensation, sex-biased expression and gene content evolution. Sex chromosomes are derived from ordinary autosomes but har...
Background and Aim This activity will guide you though some of the the initial steps in population genomic data analyses – that is, the first steps after the sequencing reads were mapped against a reference genome assembly and variants were called (if you’re interested in mapping and variant calling, check out the “Workshop on Genomics” exercises). Genetics, Chromatin Diminution, and Sex Chromosome Evolution in the Parasitic Nematode Genus Strongyloides Linda Nemetschke,1,3,4 Alexander G. Eberhardt,1,3 Hubertus Hertzberg,2 and Adrian Streit1,* 1Max Planck Institute for Developmental Biology, Spemannstrasse 35, D-72076 Tu¨bingen, Germany 2Institute for Parasitology, University of Zu¨rich,
Abstract. Comparative genomics can do more than trace how the pieces of the giant genomic jigsaw have been shuffled in evolution. A knowledge of the location and arrangement of genes in different mammals and other vertebrates can be used to deduce how gene functions diverged and genetic control systems evolved. This situation could have influenced the further evolution of sex chromosomes in marsupials. ... We complete our analysis with the localization of phosphoproteins recognized by the MPM-2 antibody, ... 1992 Role of the pseudoautosomal region in sex chromosome pairing during male meiosis: meiotic studies in a man with a deletion of distal Xp. Am. J. Isolation and genomic analysis of the cetacean Y-chromosome Vittoria Louise Elliott This thesis is submitted for consideration for the qualification of Doctor of Philosophy Biological and Biomedical Sciences, Durham University, 2010
Abstract. Initially thought to be functionally inert, the Y chromosome has now been established not only as a regulator organizer of sex determination and a functional hub for spermatogenesis but also as a genetic center involved in mediating autosomal functions and genome-wide expressions. In memory of Ingemar Gustavsson 23rd International Colloquium on Animal Cytogenetics and Genomics (23 ICACG) took place in June 9–12, 2018 in Saint-Petersburg, Russia. Organized biennially, the Colloquium runs from 1970. From its very start this meeting is associated with the name of Ingemar Gustavsson to whom we dedicated the Colloquium 2018.
The human X chromosome exhibits four “evolutionary strata,” interpreted to represent distinct steps in the process whereby recombination became arrested between the proto X and proto Y. To test if this is a general feature of sex chromosome evolution, we studied the Z-W sex chromosomes of birds, which have female rather than male heterogamety and evolved from a different autosome pair than ... Cytogenetics is a branch of genetics that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis and meiosis. Techniques used include karyotyping, analysis of G-banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization (FISH) and comparative genomic hybridization ... We demonstrate genetically that S. papillosus employs sex-specific chromatin diminution to eliminate an internal portion of one of the two homologs of one chromosome pair in males. Contrary to ascarids, the eliminated DNA in S. papillosus contains a large number of genes. We demonstrate that the region undergoing diminution is homologous to the X chromosome of the closely related S. ratti.
Sex chromosomes have evolved multiple times in many taxa. The recent explosion in the availability of whole genome sequences from a variety of organisms makes it possible to investigate sex chromosome evolution within and across genomes. Comparative genomic studies have shown that quite distant species may share fundamental properties of sex chromosome evolution, while very similar species can ... Furthermore, papaya has been recognized as an excellent model for studies about sex determination in plants (Ming et al., 2012; Aryal and Ming, 2014), sex chromosome evolution (Weingartner and Moore, 2012), origin and evolution of dioecy in the Caricaceae family, and the identification of candidate genes and genome-wide DNA markers for papaya ... Sex-determining mechanisms are highly variable and labile and sex chromosomes often degenerate; however, the underlying evolutionary mechanisms are unclear. Theoretical studies predict that sex chromosome evolution is driven by sex ratio selection and/or by different forms of genetic conflict, for example, between males and females or between cytoplasm and nucleus.
Author Summary Using recently available marsupial and monotreme genomes, we investigated nascent sex chromosome evolution in mammals. We show that, in eutherian mammals, X and Y genes acquired distinct evolutionary rates and functional constraints immediately after recombination suppression; X-linked genes maintained lower, ancestral (autosomal), rates, whereas the evolutionary rates of Y ... Genomic identification and characterization of the pseudoautosomal region in highly differentiated avian sex chromosomes. ... A widely accepted model of sex chromosome evolution implies gradual or sequential expansion of recombination restriction between the Z ... Molecular evolutionary and population genomic analysis.
For nearly all non-model organisms, however, knowledge of chromosomal gene content is minimal and difficult to obtain on a genomic scale. In this study, we utilized Comparative Genomic Hybridization (CGH), using probes designed from EST sequence, to identify genes located on the X chromosome of four species in the stalk-eyed fly genus Teleopsis. Europe PMC is an archive of life sciences journal literature. Sex chromosome evolution: platypus gene mapping suggests that part of the human X chromosome was originally au tosomal. Case Example 1: Genetics as an important determinant of biological sex: In 1959, chromosomal analysis of two human disorders, Turner syndrome and Klinefelter syndrome, demonstrated for the first time that genetic factors on the Y chromosomes of mammals are important determinants in male sex.
Evolution of Genomic Structures on Mammalian Sex Chromosomes Article (PDF Available) in Current Genomics 13(2):115-23 · April 2012 with 262 Reads How we measure 'reads' Genetics, Chromatin Diminution, and Sex Chromosome Evolution in the Parasitic Nematode Genus Strongyloides. ... For this analysis, we treated all nonoverlapping ESTs as independent units. In some cases, neighboring ESTs belonged to the same gene. Mendels Laws of Inheritance, Lethality and Interaction of Genes, Multiple Alleles, Mitosis and Meiosis, Chromosome theory of Inheritance, Fine Structure of Gene, Plasmids, IS Elements, Transposons and Retroelements
The sex-determining chromosome 1 had a higher rate of genome rearrangements than observed in autosomes 2 and 3 of Ae. aegypti. The study developed a physical map of 45% of the Ae. aegypti genome and provided new insights into genomic composition and evolution of Ae. aegypti chromosomes. 3. Evolution of the medaka Y-chromosome. Numerous studies on the heterogametic sex chromosomes of various plant and animal species and theoretical considerations have led to general concepts for a stepwise process of Y-chromosome evolution (see Charlesworth, 2004a, Charlesworth, 2004b, Charlesworth et al., 2005, Graves, 2006, Waters et al., 2007 for reviews).
Sex Chromosome Evolution. In contrast to many other taxa, therian mammals and birds are characterized by highly conserved systems of genetic sex determination that lead to special chromosomes, i.e. the sex chromosomes. Although the XX/XY sex chromosome system is the most common among eutherian species, it is not universal. Additionally, theory has long suggested that the evolution of sexual dimorphism is facilitated by sex chromosomes, as these are the only portions of the genome that differ between males and females. Genomic analysis indicates that there is indeed a relationship between sexual dimorphism and the sex chromosomes. Sex Chromosome Evolution. In contrast to many other taxa, therian mammals and birds are characterized by highly conserved systems of genetic sex determination that lead to special chromosomes, i.e. the sex chromosomes. Although the XX/XY sex chromosome system is the most common among eutherian species, it is not universal.
The comparative genomic analysis of these six Glossina species highlights the important aspects of Glossina evolution and provides further insights into their unique biology. Additional documentation of other comparative analyses is included in Additional file 1. Chromosome Dynamics and the Evolution of Sex We are developing the spectacular plant genus Oenothera (evening primrose) into a model system to answer fundamental questions about the evolutionary significance of chromosome recombination and segregation, as well as the roles of chromosome translocations and hybridization,respectively, in speciation.
A chromosome-level assembly of the ostrich Z chromosome (or of any other Paleognath species) is important for studies of avian sex chromosome evolution, for several reasons. First, it would help to reveal the ancestral state of avian sex chromosomes, prior to the divergence of Paleognathae and Neognathae, and prior to the onset of sex chromosome differentiation. Evolutionary theory predicts that in dioecious organisms with sex chromosomes, suppressed X-Y recombination should lead to a loss of Y-chromosome gene content and function. However, the extent to which this process occurs in plants, where sex chromosomes evolved relatively recently, is poorly understood. We tested for Y degeneration in Rumex hastatulus , an annual plant that has both XY and ... This transfer led to the evolution of a completely new sex chromosome. “Our results show above all the complexity of factors that contribute to patterns observed in hybrid genomes including such fundamental issues such as sex determination,” summarises Paolo Franchini.
The human X and Y chromosomes evolved from a pair of autosomes approximately 180 million years ago. Despite their shared evolutionary origin, extensive genetic decay has resulted in the human Y ... The sex-determining chromosome 1 had a higher rate of genome rearrangements than observed in autosomes 2 and 3 of Ae. aegypti. CONCLUSIONS: The study developed a physical map of 45% of the Ae. aegypti genome and provided new insights into genomic composition and evolution of Ae. aegypti chromosomes. The Blackmon Lab is in the Biology Department at Texas A&M University. We have two broad areas of inquiry. The first is genome evolution, specifically sex chromosome and structural evolution. The second is the development of methods and databases that accelerate the analysis of data within a quantitative genetic or phylogenetic framework.