The maleless gene mitigates global aneuploid effect and evolutionary shift from X to autosomes
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE78227 | GEO | 2016/03/31
SECONDARY ACCESSION(S): PRJNA312952
REPOSITORIES: GEO
Similar Datasets
Project description:During sexual dimorphism, the loss of one entire X chromosome in Drosophila males is achieved largely via a broad genome-wide aneuploid effect. Exploring how MSL proteins and two large non coding RNAs (roX1 and roX2) modulate trans-acting aneuploid effect for equality to females, we employ a system biology approach (microarray) to investigate the global aneuploid effect of maleless(mle) mutation by disrupting MSL binding. A large number of the genes (144) that encode a broad spectrum of cellular transport proteins and transcription factors are located in the autosomes of Drosophila melanogaster. We find these autosomal targets are sensitive to the aneuploid effect and are poorly conserved in primitive Drosophila species and Anopheles gambiae autosomes. It is expected that during evolutionary process, they shifted gradually from their X chromosomal position in primitive Drosophila to autosomes in melanogaster, suggesting that MSL favors inverse counteraction of these autosomal targets along with X-linked genes. These findings suggest a remarkable and previously unsuspected level of complexity among aneuploid-sensitive genes, that creates a functional shift of the aneuploid effect from X to autosomes during evolution, which is resolved by the binding of MSL complex on the X chromosome.. Drosophila larvae were selected based on genotypes particularly with Tb phenotypes. Total cellular RNA were extracted from each genotypes and hebridized with affymetrix Drosophila Microarray chip. Gene Expression profiling of fly base to understand the role of maleless mutation in aneuploid targets.
2016-03-31 | E-GEOD-78227 | 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
Project description:Drosophila males double transcription of their single X chromosome to equalize X-linked gene expression with females, which carry two X chromosomes. Increased transcription requires the Male-Specific Lethal (MSL) complex. One of the primary functions of the MSL complex is thought to be enrichment of H4Ac16 on the male X chromosome, a modification linked to elevated transcription. The roX1 and roX2 RNAs are essential but redundant components of the MSL complex. Simultaneous removal of both roX RNAs reduces MSL X-localization and leads to ectopic binding of these proteins at autosomal sites and to the chromocenter. Some H4Ac16 accumulates at these ectopic sites in roX1- roX2- males, suggesting the possibility of increased expression. The global effect of roX mutations on gene expression was measured by microarray analysis. We found that expression of the X chromosome was decreased by 26% in roX1- roX2- male larvae, supporting the involvement of roX RNAs in the up-regulation of X-linked genes. This finding is broadly comparable to reports of reduced X chromosome expression following msl2 RNAi knockdown in S2 cells. In spite of strong MSL binding and H4Ac16 accumulation at autosomal sites in roX1- roX2- males, enhanced gene expression could not be detected at these sites by microarray analysis or reverse northern blotting. Thus, failure to compensate X-linked genes, rather than inappropriate up-regulation of autosomal genes at ectopic sites of MSL binding, appears to cause male lethality upon loss of roX RNAs. Experiment Overall Design: Total RNA was prepared from groups of 50 third instar larvae by TRIzol (Invitrogen) extraction and purified using the RNeasy kit (Qiagen). Three independent RNA preparations for each genotype served as templates for probe synthesis. Affymetrix Drosophila Genome 2.0 chips were hybridized to these probes (Santa Clara, CA). The affymertrix Drosophila annotation of December 2004 was used to map genes to their cytological locations. Genes were filtered for present/absent calls by a PM-MM (Perfect match- Mismatch) comparison. Autosomal transcripts were normalized on a chip-by-chip basis to bring their median values to 100. The identical degree of adjustment was used to normalize X-linked transcripts. Changes in gene expression were determined by comparing the mean signal intensities of genes on arrays hybridized with roX1SMC17A roX2- probes to those hybridized with roX1+ roX2- probes.
2008-03-13 | E-GEOD-3990 | 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. We sequenced mRNA from D. pseudoobscura and D. miranda embryos, from eight timepoints, both female and male embryos, with three replicates (2 x 8 x 2 x 3). D. pseudoobscura embryos were F1s of a cross between Flagstaff-14 and PP1134 D. pseudoobscura lines, D. miranda embryos were F1s of a cross between the MSH22 and SP138 D. miranda lines.
2014-02-14 | E-GEOD-53483 | biostudies-arrayexpress
Project description:Drosophila males double transcription of their single X chromosome to equalize X-linked gene expression with females, which carry two X chromosomes. Increased transcription requires the Male-Specific Lethal (MSL) complex. One of the primary functions of the MSL complex is thought to be enrichment of H4Ac16 on the male X chromosome, a modification linked to elevated transcription. The roX1 and roX2 RNAs are essential but redundant components of the MSL complex. Simultaneous removal of both roX RNAs reduces MSL X-localization and leads to ectopic binding of these proteins at autosomal sites and to the chromocenter. Some H4Ac16 accumulates at these ectopic sites in roX1- roX2- males, suggesting the possibility of increased expression. The global effect of roX mutations on gene expression was measured by microarray analysis. We found that expression of the X chromosome was decreased by 26% in roX1- roX2- male larvae, supporting the involvement of roX RNAs in the up-regulation of X-linked genes. This finding is broadly comparable to reports of reduced X chromosome expression following msl2 RNAi knockdown in S2 cells. In spite of strong MSL binding and H4Ac16 accumulation at autosomal sites in roX1- roX2- males, enhanced gene expression could not be detected at these sites by microarray analysis or reverse northern blotting. Thus, failure to compensate X-linked genes, rather than inappropriate up-regulation of autosomal genes at ectopic sites of MSL binding, appears to cause male lethality upon loss of roX RNAs. Keywords: effect of roX1-roX2- mutant on gene expression
2007-01-06 | GSE3990 | GEO
Project description:Chromosomal and segmental aneuploidies are usually lethal or common features of cancer cells and variety of disease, but little is known about how copy number relates to gene expression. Drosophila males have a single X chromosome and two sets of autosomes, but X chromosome and autosome transcripts are equally abundant. This 2-fold increase in X chromosome gene expression requires a dosage compensation complex (MSL) that acetylates histone 4 at lysine 16 (H4AcK16). To determine the contribution of general buffering and MSL to X chromosome dosage compensation, we analyzed genome-wide copy number, expression and histone modification pattern in male Drosophila S2 cells with and without MSL. Keywords: Gene Regulation Study, genomic analyses
2010-01-11 | GSE16344 | GEO
Project description:Chromosomal and segmental aneuploidies are usually lethal or common features of cancer cells and variety of disease, but little is known about how copy number relates to gene expression. Drosophila males have a single X chromosome and two sets of autosomes, but X chromosome and autosome transcripts are equally abundant. This 2-fold increase in X chromosome gene expression requires a dosage compensation complex (MSL) that acetylates histone 4 at lysine 16 (H4AcK16). To determine the contribution of general buffering and MSL to X chromosome dosage compensation, we analyzed genome-wide copy number, expression and histone modification pattern in male Drosophila S2 cells with and without MSL. Keywords: Gene Regulation Study, genomic analyses RNA-seq and microarray were performed in Drosophila non-treated or RNAi treated S2 cells. Two biological replicates were used for expression profile. DNA-seq and CGH were performed (CGH data forthcoming) to check the copy number variation in S2 cells. Chromatin immunoprecipitations were performed in Drosophila non-treated or RNAi treated S2 cells with different histone modification antibodies. At least three biological replicates were performed for each antibody and treatment.
2010-01-11 | E-GEOD-16344 | biostudies-arrayexpress
Project description:MSL (Male-specific lethal) complex increases transcription on the single X chromosome of Drosophila males in order to equalize expression of X-linked genes between males (XY) and females (XX). The increase in transcript levels correlates with MSL- dependent acetylation of histone H4 at K16 within the bodies of active genes, but identification of the transcriptional step affected has not been possible. In this study, we use global run-on sequencing (GRO-seq) to examine the specific effect of MSL complex on RNA Polymerase II (RNAP II) on a genome-wide level. Results indicate that MSL complex enhances transcription by facilitating the progression of RNAP II across the bodies of active X-linked genes. Improving transcriptional output downstream of typical gene-specific control may explain how dosage compensation can be imposed on the diverse set of genes along an entire chromosome. Global Run-On Sequencing (GRO-Seq) reads, i.e., RNA-Seq of nascent RNA transcripts, from D. Melanogaster SL2 cells. Two biological replicates were analyzed.
2010-12-22 | E-GEOD-25321 | biostudies-arrayexpress
Project description:Confinement of the X chromosome into a territory for dosage compensation (DC) is a prime example of subnuclear compartmentalization for transcription regulation at the megabase scale. In D. melanogaster, two sex-specific non-coding (nc) RNAs roX1 and roX2 are transcribed from the X chromosome. They associate with the Male-specific lethal (MSL) complex, which by acetylating histone H4 lysine 16 (H4K16ac) confers approximately 2-fold upregulated expression of male X-linked genes. Current models explain X-over-autosome specificity based on the MSL2 subunit recognizing cis-regulatory DNA high-affinity sites (HAS). However, HAS motifs are also found on autosomes, indicating that additional factors have evolved to confer stable association of the MSL complex with the X. Here, we show that the low-complexity C-terminal domain (CTD) of MSL2 renders its recruitment to the X chromosome sensitive to roX ncRNAs. roX-MSL2-CTD form a stably condensated state, and functional analyses in Drosophila and mammalian cells reveal the critical importance of their interplay for DC in vivo. Replacing the CTD of mammalian MSL2 with that from Drosophila and expressing roX in cis is sufficient to nucleate ectopic DC in mammalian cells. Thus, the condensating nature of roX-MSL2CTD is the primary determinant for specific compartmentalization of the X in Drosophila.
2020-08-07 | GSE129795 | GEO
Project description:Confinement of the X chromosome into a territory for dosage compensation (DC) is a prime example of subnuclear compartmentalization for transcription regulation at the megabase scale. In D. melanogaster, two sex-specific non-coding (nc) RNAs roX1 and roX2 are transcribed from the X chromosome. They associate with the Male-specific lethal (MSL) complex, which by acetylating histone H4 lysine 16 (H4K16ac) confers approximately 2-fold upregulated expression of male X-linked genes. Current models explain X-over-autosome specificity based on the MSL2 subunit recognizing cis-regulatory DNA high-affinity sites (HAS). However, HAS motifs are also found on autosomes, indicating that additional factors have evolved to confer stable association of the MSL complex with the X. Here, we show that the low-complexity C-terminal domain (CTD) of MSL2 renders its recruitment to the X chromosome sensitive to roX ncRNAs. roX-MSL2-CTD form a stably condensated state, and functional analyses in Drosophila and mammalian cells reveal the critical importance of their interplay for DC in vivo. Replacing the CTD of mammalian MSL2 with that from Drosophila and expressing roX in cis is sufficient to nucleate ectopic DC in mammalian cells. Thus, the condensating nature of roX-MSL2CTD is the primary determinant for specific compartmentalization of the X in Drosophila.
2020-08-07 | GSE129831 | GEO