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PROVIDER: PRJNA512892 | ENA |
REPOSITORIES: ENA
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Project description:Mechanisms of X chromosome dosage compensation have been studied extensively in a few model species representing clades of shared sex chromosome ancestry. However, the diversity within each clade as a function of sex chromosome evolution is largely unknown. Here, we anchor ourselves to the nematode Caenorhabditis elegans, for which a well-studied mechanism of dosage compensation occurs through a specialized structural maintenance of chromosomes (SMC) complex, and explore the diversity of dosage compensation in the surrounding phylogeny of nematodes. Through phylogenetic analysis of the C. elegans dosage compensation complex and a survey of its epigenetic signatures, including X-specific topologically associating domains (TADs) and X-enrichment of H4K20me1, we found that the condensin-mediated mechanism evolved recently in the lineage leading to Caenorhabditis through an SMC-4 duplication. Intriguingly, an independent duplication of SMC-4 and the presence of X-specific TADs in Pristionchus pacificus suggest that condensin-mediated dosage compensation arose more than once. mRNA-seq analyses of gene expression in several nematode species indicate that dosage compensation itself is ancestral, as expected from the ancient XO sex determination system. Indicative of the ancestral mechanism, H4K20me1 is enriched on the X chromosomes in Oscheius tipulae, which does not contain X-specific TADs or SMC-4 paralogs. Together, our results indicate that the dosage compensation system in C. elegans is surprisingly new, and condensin may have been co-opted repeatedly in nematodes, suggesting that the process of evolving a chromosome-wide gene regulatory mechanism for dosage compensation is constrained.
2024-05-21 | GSE267962 | GEO
Project description:Drosophila X chromosomes are subject to dosage compensation in males and are known to have a specialized chromatin structure in the male soma. We are interested in how specific chromatin structure change contributes to X chromosome hyperactivity and dosage compensation. We have conducted a global analysis of localize two dosage compensation complex dependent histone marks H4AcK16 and H3PS10 and one dosage compensation complex independent histone mark H3diMeK4 in the genome, especially on X chromosome by ChIP-chip approach in both male and female adult flies. We also probed general genomewide chromatin structure by deep DNA sequencing of sheared ChIP input DNA from male and female adult flies.
2010-01-11 | GSE15593 | GEO
Project description:Long non-coding RNAs are involved in dosage compensation both in mammals and in Drosophila by inducing changes in the X-chromosome chromatin structure. In Drosophila melanogaster, roX1 and roX2 are long non-coding RNAs that together with proteins form the male-specific lethal (MSL) complex, which coats the entire male X-chromosome and mediates dosage compensation by increased transcriptional output. It has been shown that in polytene chromosomes, in absence of both roX1 and roX2, the MSL-complex is decreased on the male X-chromosome and found relocated to the chromocenter, and the 4th chromosome. Here we address the role of roX RNAs in MSL-complex targeting and in the evolution of dosage compensation in Drosophila. We performed ChIP-seq experiments and show that MSL-complex recruitment to high affinity sites (HAS) on the X-chromosome is independent on roX and that the HAS sequence motif is conserved in D. simulans. Additionally, a complete and enzymatically active MSL-complex is recruited to six specific genes on the 4th chromosome. Interestingly, our sequence analysis shows that in the absence of roX RNAs, the MSL-complex has affinity to regions enriched in Hoppel transposable elements and to repeats in general. We hypothesize that roX mutants reveal an ancient targeting of the MSL-complex and propose that the role of roX RNAs is to restrict MSL-complex from binding to heterochromatin.
2014-11-07 | GSE58768 | GEO
Project description:Copy-number variants (CNVs) are large-scale amplifications or deletions of DNA that can drive rapid adaptive evolution and result in large-scale changes in gene expression. Whereas alterations in the copy number of one or more genes within a CNV can confer a selective advantage, other genes within a CNV can decrease fitness when their dosage is changed. Dosage compensation - in which the gene expression output from multiple gene copies is less than expected - is one means by which an organism can mitigate the fitness costs of deleterious gene amplification. Previous research has shown evidence for dosage compensation at both the transcriptional level and at the level of protein expression; however, the extent of compensation differs substantially between genes, strains, and studies. Here, we investigated sources of dosage compensation at multiple levels of gene expression regulation by defining the transcriptome, translatome and proteome of experimentally evolved yeast (Saccharomyces cerevisiae) strains containing adaptive CNVs.
2023-11-01 | PXD046587 | Pride
Project description:Haploinsufficiency and aneuploidy are two phenomena, where alteration of gene dosage causes severe cellular defects ultimately resulting in developmental failures and disease. One remarkable exception is the X chromosome, where copy number differences between males and females are buffered through the action of dosage compensation systems. In Drosophila, the Male-Specific Lethal complex (MSLc) mediates two-fold upregulation of the single male X chromosome via Histone H4 lysine 16 acetylation (H4K16ac). The evolutionary origin and conservation of this process orchestrated by MSL2, the only male-specific protein within the fly MSLc, have remained unclear. Here, we report that MSL2, in addition to its function on the X, targets dosage-sensitive autosomal genes involved in patterning and morphogenesis. We show that the precise regulation of these genes by MSL2 is required for proper development of the fly wing. This set of dosage sensitive genes maintained such regulation during evolution, as MSL2 binds and similarly regulates mouse orthologues via deposition of H4K16ac. We propose that MSL2-mediated H4K16ac is an evolutionarily conserved process mediating gene-by-gene dosage compensation across flies and mammals.
2018-06-29 | GSE109898 | GEO
Project description:Haploinsufficiency and aneuploidy are two phenomena, where alteration of gene dosage causes severe cellular defects ultimately resulting in developmental failures and disease. One remarkable exception is the X chromosome, where copy number differences between males and females are buffered through the action of dosage compensation systems. In Drosophila, the Male-Specific Lethal complex (MSLc) mediates two-fold upregulation of the single male X chromosome via Histone H4 lysine 16 acetylation (H4K16ac). The evolutionary origin and conservation of this process orchestrated by MSL2, the only male-specific protein within the fly MSLc, have remained unclear. Here, we report that MSL2, in addition to its function on the X, targets dosage-sensitive autosomal genes involved in patterning and morphogenesis. We show that the precise regulation of these genes by MSL2 is required for proper development of the fly wing. This set of dosage sensitive genes maintained such regulation during evolution, as MSL2 binds and similarly regulates mouse orthologues via deposition of H4K16ac. We propose that MSL2-mediated H4K16ac is an evolutionarily conserved process mediating gene-by-gene dosage compensation across flies and mammals.
2018-06-29 | GSE109897 | GEO
Project description:The essential process of dosage compensation, which corrects for the imbalance in X-linked gene expression between XX females and XY males, represents a key model for how genes are targeted for coordinated regulation. However, the mechanism by which dosage compensation complexes identify the X-chromosome during early development remained unknown because of the difficulty of sexing embryos prior to zygotic transcription. We used meiotic drive to sex Drosophila embryos prior to zygotic transcription and ChIP-seq to measure dynamics of dosage compensation factor targeting. The Drosophila Male-Specific Lethal dosage compensation complex (MSLc) requires the ubiquitous zinc-finger protein Chromatin-Linked Adaptor for MSL Proteins (CLAMP) to identify the X-chromosome. We observe a multi-stage process in which MSLc first identifies CLAMP binding sites throughout the genome followed by concentration at the strongest X-linked MSLc sites. We provide insight into the dynamic mechanism by which a large transcription complex identifies its binding sites during early development.
2019-12-01 | GSE133637 | GEO
Project description:Mechanisms of X chromosome dosage compensation have been studied extensively in a few model species representing clades of shared sex chromosome ancestry. However, the diversity within each clade as a function of sex chromosome evolution is largely unknown. Here, we anchor ourselves to the nematode Caenorhabditis elegans, for which a well-studied mechanism of dosage compensation occurs through a specialized structural maintenance of chromosomes (SMC) complex, and explore the diversity of dosage compensation in the surrounding phylogeny of nematodes. Through phylogenetic analysis of the C. elegans dosage compensation complex and a survey of its epigenetic signatures, including X-specific topologically associating domains (TADs) and X-enrichment of H4K20me1, we found that the condensin-mediated mechanism evolved recently in the lineage leading to Caenorhabditis through an SMC-4 duplication. Intriguingly, an independent duplication of SMC-4 and the presence of X-specific TADs in Pristionchus pacificus suggest that condensin-mediated dosage compensation arose more than once. mRNA-seq analyses of gene expression in several nematode species indicate that dosage compensation itself is ancestral, as expected from the ancient XO sex determination system. Indicative of the ancestral mechanism, H4K20me1 is enriched on the X chromosomes in Oscheius tipulae, which does not contain X-specific TADs or SMC-4 paralogs. Together, our results indicate that the dosage compensation system in C. elegans is surprisingly new, and condensin may have been co-opted repeatedly in nematodes, suggesting that the process of evolving a chromosome-wide gene regulatory mechanism for dosage compensation is constrained.
2024-05-21 | GSE267963 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE34857: Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context (ChIP-chip) GSE34858: Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context (mRNA) Refer to individual Series
2012-03-19 | E-GEOD-34859 | biostudies-arrayexpress
Project description:Sex chromosome dosage differences between males and females are a significant form of natural genetic variation in many species. Like many species with chromosomal sex determination, Drosophila females have two X chromosomes, while males have one X and one Y. The model species D. melanogaster has five roughly equally sized chromosome arms, one of which is the X chromosome. However, fusions of sex chromosomes with autosomes have occurred along the lineage leading to D. pseudoobscura and D. miranda. The resulting neo-sex chromosomes are gradually evolving the properties of sex chromosomes, and neo-X chromosomes are becoming targets for the molecular mechanisms that compensate for differences in X chromosome dose between sexes. We have previously shown that D. melanogaster possess at least two dosage compensation mechanisms: the well- characterized MSL-mediated dosage compensation active in most somatic tissues, and another system active during early embryogenesis prior to the onset of MSL-mediated dosage compensation. To better understand the developmental constraints on sex chromosome gene expression and evolution, we sequenced mRNA from individual male and female embryos of D. pseudoobscura and D. miranda, from ~0.5 to 8 hours of development. Autosomal expression levels are highly conserved between these species. But, unlike D. melanogaster, we observe a general lack of dosage compensation in D. pseudoobscura and D. miranda prior to the onset of MSL-mediated dosage compensation. The extent of female bias on the X chromosomes decreases through developmental time with the establishment of MSL-mediated dosage compensation, but may do so more slowly in D. miranda than D. pseudoobscura. Thus either there has been a lineage-specific gain or loss in early dosage compensation mechanism(s), or increasing X chromosome dose may strain dosage compensation systems and make them less effective. These results also prompt a number of questions about whether species with more sex-linked genes have more sex-specific phenotypes, and how much transcript level variance is tolerable during critical stages of development.
2014-02-14 | GSE53483 | GEO