Genome-wide profiling of RNA associated to the chromosome 4 specific protein POF in Drosophila melanogaster
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE28518 | GEO | 2012/05/31
SECONDARY ACCESSION(S): PRJNA143049
REPOSITORIES: GEO
Similar Datasets
Project description:In Drosophila, two chromosome-wide compensatory systems have been characterized; the dosage compensation system acting on the male X-chromosome and the chromosome specific regulation of genes located on the heterochromatic 4th chromosome. Dosage compensation in Drosophila is accomplished by hypertranscription of the single male X-chromosome mediated by the MSL-complex. The mechanism for this compensation is suggested to be an MSL-complex mediated enhanced transcriptional elongation while the mechanism for the compensation mediated by Painting of fourth (POF) on the 4th chromosome has remained elusive. Here we show that POF binds to nascent RNA and this binding is associated with an increase in amount of chromosome 4 transcripts. Furthermore, genes located on the 4th chromosome are enriched in binding of the nucleoplasmic nucleporin component NUP98 and this enrichment correlates to increased POF binding. We also show that genes located in heterochromatic regions have a shorter transition time from site of transcription and to the nuclear envelope. Our current work broadens the understanding about how genes in heterochromatic regions can overcome the repressive influence of their hostile environment. Pof mutant vs. wild type, 3 replicates
2012-05-30 | E-GEOD-28513 | biostudies-arrayexpress
Project description:In Drosophila, two chromosome-wide compensatory systems have been characterized; the dosage compensation system acting on the male X-chromosome and the chromosome specific regulation of genes located on the heterochromatic 4th chromosome. Dosage compensation in Drosophila is accomplished by hypertranscription of the single male X-chromosome mediated by the MSL-complex. The mechanism for this compensation is suggested to be an MSL-complex mediated enhanced transcriptional elongation while the mechanism for the compensation mediated by Painting of fourth (POF) on the 4th chromosome has remained elusive. Here we show that POF binds to nascent RNA and this binding is associated with an increase in amount of chromosome 4 transcripts. Furthermore, genes located on the 4th chromosome are enriched in binding of the nucleoplasmic nucleporin component NUP98 and this enrichment correlates to increased POF binding. We also show that genes located in heterochromatic regions have a shorter transition time from site of transcription and to the nuclear envelope. Our current work broadens the understanding about how genes in heterochromatic regions can overcome the repressive influence of their hostile environment.
2012-05-31 | GSE28513 | GEO
Project description:In Drosophila melanogaster, two chromosome-specific targeting and regulatory systems have been described. The male-specific lethal (MSL) complex supports dosage compensation by stimulating gene expression from the male X-chromosome and the protein Painting of fourth (POF) specifically targets and stimulates expression from the heterochromatic 4th chromosome. The targeting sites of both systems are well characterized, but the principles underlying the targeting mechanisms have remained elusive. Here we present an original observation, namely that POF specifically targets two loci on the X-chromosome, PoX1 and PoX2 (POF-on-X). PoX1 and PoX2 are located close to the roX1 and roX2 genes, which encode ncRNAs important for the correct targeting and spreading of the MSL-complex. We also found that the targeting of POF to PoX1 and PoX2 is largely dependent on roX expression and identified a high-affinity target region which ectopically recruits POF. The results presented support a model linking the MSL-complex to POF and dosage compensation to regulation of heterochromatin.
2013-05-27 | GSE45402 | GEO
Project description:In Drosophila melanogaster, two chromosome-specific targeting and regulatory systems have been described. The male-specific lethal (MSL) complex supports dosage compensation by stimulating gene expression from the male X-chromosome and the protein Painting of fourth (POF) specifically targets and stimulates expression from the heterochromatic 4th chromosome. The targeting sites of both systems are well characterized, but the principles underlying the targeting mechanisms have remained elusive. Here we present an original observation, namely that POF specifically targets two loci on the X-chromosome, PoX1 and PoX2 (POF-on-X). PoX1 and PoX2 are located close to the roX1 and roX2 genes, which encode ncRNAs important for the correct targeting and spreading of the MSL-complex. We also found that the targeting of POF to PoX1 and PoX2 is largely dependent on roX expression and identified a high-affinity target region which ectopically recruits POF. The results presented support a model linking the MSL-complex to POF and dosage compensation to regulation of heterochromatin. POF salivary glands ChIP
2013-05-27 | E-GEOD-45402 | biostudies-arrayexpress
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: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: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:Two chromosome-targeting and gene regulatory systems are present in Drosophila melanogaster. The male X-chromosome is targeted by the male-specific lethal complex believed to mediate the two-fold up-regulation of the X-linked genes. The highly heterochromatic 4th chromosome is specifically targeted by the Painting of Fourth (POF) protein which together with heterochromatin protein 1 (HP1) modulate the expression level of genes on the 4th chromosome. Here we report high-resolution mapping of POF and HP1 on the 4th chromosome using chromatin immunoprecipitation followed by tiling microarrays (ChIP-chip) in S2 cells and salivary glands. The enrichments are compared to transcript profiles of the two cell types used. POF specifically binds to genes with a strong preference for exons. The POF binding profile correlates to the binding profile of HP1 which in addition displays a typical “peak” in the promoter regions of bound genes. POF and HP1 binds to active genes and the binding correlates with levels of transcription and changes in binding levels are paralleled by a comparable change in transcription. Our results provide a high resolution description of the chromosome 4 specific gene regulatory system provided by the combinatorial effects of POF and HP1. This SuperSeries is composed of the SubSeries listed below.
2007-10-03 | GSE8301 | GEO
Project description:Two chromosome-targeting and gene regulatory systems are present in Drosophila melanogaster. The male X-chromosome is targeted by the male-specific lethal complex believed to mediate the two-fold up-regulation of the X-linked genes. The highly heterochromatic 4th chromosome is specifically targeted by the Painting of Fourth (POF) protein which together with heterochromatin protein 1 (HP1) modulate the expression level of genes on the 4th chromosome. Here we report high-resolution mapping of POF and HP1 on the 4th chromosome using chromatin immunoprecipitation followed by tiling microarrays (ChIP-chip) in S2 cells and salivary glands. The enrichments are compared to transcript profiles of the two cell types used. POF specifically binds to genes with a strong preference for exons. The POF binding profile correlates to the binding profile of HP1 which in addition displays a typical “peak” in the promoter regions of bound genes. POF and HP1 binds to active genes and the binding correlates with levels of transcription and changes in binding levels are paralleled by a comparable change in transcription. Our results provide a high resolution description of the chromosome 4 specific gene regulatory system provided by the combinatorial effects of POF and HP1. Keywords: Transcript profiling
2007-10-03 | GSE8297 | GEO
Project description:Two chromosome-targeting and gene regulatory systems are present in Drosophila melanogaster. The male X-chromosome is targeted by the male-specific lethal complex believed to mediate the two-fold up-regulation of the X-linked genes. The highly heterochromatic 4th chromosome is specifically targeted by the Painting of Fourth (POF) protein which together with heterochromatin protein 1 (HP1) modulate the expression level of genes on the 4th chromosome. Here we report high-resolution mapping of POF and HP1 on the 4th chromosome using chromatin immunoprecipitation followed by tiling microarrays (ChIP-chip) in S2 cells and salivary glands. The enrichments are compared to transcript profiles of the two cell types used. POF specifically binds to genes with a strong preference for exons. The POF binding profile correlates to the binding profile of HP1 which in addition displays a typical “peak” in the promoter regions of bound genes. POF and HP1 binds to active genes and the binding correlates with levels of transcription and changes in binding levels are paralleled by a comparable change in transcription. Our results provide a high resolution description of the chromosome 4 specific gene regulatory system provided by the combinatorial effects of POF and HP1. Keywords: ChIP-chip
2007-10-03 | GSE8296 | GEO