Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA117171 | ENA |
REPOSITORIES: ENA
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Project description:Effects of Nipped-B and Rad21 sister chromatid cohesin proteins on gene expression data in ML-DmBG3 cells derived from Drosophila melanogaster larval central nervous system We examined the effects of Nipped-B and Rad21 knockdown on gene expression in BG3 cells using microarrays that measure over 18,700 transcripts to (a) determine if the effects of cohesion on E(spl)-C and invected-engrailed expression are unique, (b) look for effects of cohesin on regulators of E(spl)-C and engrailed, and (c) obtain a comprehensive view of the effects of cohesin on gene expression.
2009-05-19 | GSE16152 | GEO
Project description:Effects of Nipped-B and Rad21 sister chromatid cohesin proteins on gene expression data in ML-DmBG3 cells derived from Drosophila melanogaster larval central nervous system; We examined the effects of Nipped-B and Rad21 knockdown on gene expression in BG3 cells using microarrays that measure over 18,700 transcripts to (a) determine if the effects of cohesion on E(spl)-C and invected-engrailed expression are unique, (b) look for effects of cohesin on regulators of E(spl)-C and engrailed, and (c) obtain a comprehensive view of the effects of cohesin on gene expression. Experiment Overall Design: Effects of cohesin knockdown on E(spl)-C and invected-engrailed transcription vary over time, so we used two independent samples for three days after RNAi treatment, one four day and one six day sample for both Nipped-B and Rad21 knockdown, and mock RNAi controls for each time point. Experiment Overall Design: For RNAi treatment, cells were plated at 5x106 cells per 3 cm well. Media was replaced with 1 ml of Express Five SFM (Invitrogen) with 1% FCS, and 10 micrograms per ml insulin. The indicated amount of dsRNA was added per well. Media was adjusted to 3 ml and 10% FCS with Schneiderâs media after 2 hrs. Cells were replated as needed. Templates for dsRNA synthesis were made by PCR from cDNA templates using primers with T7 promoters (see supplementary file linked below). Equal amounts of two dsRNAs against each target were used.
2009-05-27 | E-GEOD-16152 | biostudies-arrayexpress
Project description:The fidelity of chromosome duplication through cell divisions requires timely binding and release of the cohesin. Cohesin is a ring-shaped protein complex linking newly replicated sister chromatids to ensure their appropriate transmission through mitosis. Upon commencement of mitosis cohesin is removed from DNA in two steps: first, from chromosome arms resulting in sister chromatid resolution, and, second, from centromers leading to sister chromatid segregation. As DNA of eukaryotic chromosomes is assembled into chromatin, regulation of sister chromatid cohesion-segregation may involve chromatin modifying machinery, but this link is not well understood. Here we report that H2A-H2B histone chaperone NAP1, a factor, which is primarily implicated in chromatin assembly, is required for cohesin release from mitotic chromosome arms. NAP1 and cohesin protein complex interact directly and share multiple binding sites on chromatin. Depletion of the NAP1 hinders cohesin removal during mitosis resulting in accumulation of unresolved sister chromatids. Thus, in addition to its well established functions in chromatin dynamics, histone chaperone NAP1 coordinates cell cycle dependent cohesin release. These results reveal a novel molecular pathway for sister chromatid resolution and emphasizes a role for histone chaperones in control of eukaryotic genome replication and transmission. Genome-wide NAP1 and Cohesin ChIP-chip profiling in Drosophila S2 cells. The supplementary bed file S2_cohesin_sites.bed contains cohesin binding sites obtained by intersecting the sets of significant ChIP-chip peaks for SA (a cohesin subunit; stromalin) and SMC1.
2012-07-25 | E-GEOD-30938 | biostudies-arrayexpress
Project description:Developmental abnormalities observed in Cornelia de Lange Syndrome (CdLS) have been genetically linked to mutations in the cohesin machinery. These findings raise the possibility that cohesin, in addition to its canonical function of mediating sister chromatid cohesion, might also be involved in regulating gene expression. We report that cleavage of cohesin’s kleisin subunit in post-mitotic Drosophila salivary glands induces major changes (both up and down) in the transcript levels of many genes. Kinetic analyses of changes in transcript levels upon cohesin cleavage reveal that a subset of genes responds to cohesin cleavage within a few hours. In addition, cohesin binds to most of these loci, suggesting that cohesin is directly regulating their expression. Amongst these genes are several that are regulated by the steroid hormone Ecdysone. Transcripts at EcR and Eip74EF, which encode an Ecdysone Receptor and an Ecdysone-regulated transcription factor, respectively, decline ten-fold within four hours of cohesin cleavage. Cytological visualization of transcription at selected Ecdysone-responsive genes reveals that puffing at Eip74EF ceases within an hour or two of cohesin cleavage, long before any decline in EcR associated with this locus. We conclude that cohesin regulates expression of a distinct set of genes, including those mediating the Ecdysone response DamID experiments for Rad21 were performed on gDNA from drosophila salivary glands. Samples were hybridized to 380k NimbleGen arrays with 300 bp probe spacing. The experiment was done in duplicate in the reverse dye orientation.
2011-03-22 | E-GEOD-21874 | biostudies-arrayexpress
Project description:ASXL1 is frequently mutated in a spectrum of myeloid malignancies with poor prognosis. Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice, however, the underlying molecular mechanisms remain unclear. Here, we report that ASXL1 interacts with the cohesin complex, which has been shown to guide sister chromotid segregation and to regulate gene expression. Loss of Asxl1 impairs the cohesin function as reflected by an impaired telophase chromatid disjunction in hematopoietic cells. ChIP-seq data revealed that ASXL1, RAD21 and SMC1A share 93% of genomic binding sites at promoter regions in lineage-cKit+ (LK) cells. We have showed that loss of Asxl1 reduced the genome binding of RAD21 and SMC1A, and altered the expression of ASXL1/cohesin target genes in LK cells. Our study underscores the ASXL1-cohesin interaction as a novel means to maintain normal sister chromatid separation and to regulate gene expression in hematopoietic cells.
2017-02-24 | GSE83960 | GEO
Project description:ASXL1 is frequently mutated in a spectrum of myeloid malignancies with poor prognosis. Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice, however, the underlying molecular mechanisms remain unclear. Here, we report that ASXL1 interacts with the cohesin complex, which has been shown to guide sister chromotid segregation and to regulate gene expression. Loss of Asxl1 impairs the cohesin function as reflected by an impaired telophase chromatid disjunction in hematopoietic cells. ChIP-seq data revealed that ASXL1, RAD21 and SMC1A share 93% of genomic binding sites at promoter regions in lineage-cKit+ (LK) cells. We have showed that loss of Asxl1 reduced the genome binding of RAD21 and SMC1A, and altered the expression of ASXL1/cohesin target genes in LK cells. Our study underscores the ASXL1-cohesin interaction as a novel means to maintain normal sister chromatid separation and to regulate gene expression in hematopoietic cells.
2017-02-24 | GSE83961 | GEO
Project description:RNA expression was measured by RNA-seq in Drosophila ML-DmBG3-c2 cells depleted for proteins involved in sister chromatid cohesion, and in developing third instar wing discs with or withough brca2 gene mutations
2018-02-05 | GSE109385 | GEO
Project description:Cohesin is a well-known mediator of sister chromatid cohesion, but it also influences gene expression and development. These non-canonical roles of cohesin are not well understood, but are vital: gene expression and development are altered by modest changes in cohesin function that do not disrupt chromatid cohesion. To clarify cohesinM-bM-^@M-^Ys roles in transcription, we measured how cohesin controls RNA polymerase II (Pol II) activity by genome-wide chromatin immunoprecipitation and precision global run-on sequencing. On average, cohesin-binding genes have more transcriptionally active Pol II and promoter-proximal Pol II pausing than non-binding genes, and are more efficient, producing higher steady state levels of mRNA per transcribing Pol II complex. Cohesin depletion frequently increases pausing at cohesin-binding genes, indicating that cohesin often facilitates transition of paused Pol II to elongation. In many cases this likely reflects a role for cohesin in transcriptional enhancer function. Strikingly, more than 95% of predicted extragenic enhancers bind cohesin, and cohesin depletion can reduce their association with Pol II, indicating that cohesin facilitates enhancer-promoter contact. Cohesin directly promotes transcription of the myc gene, and cohesin depletion reduces Pol II activity at most Myc target genes. The multiple transcriptional roles of cohesin revealed by these studies likely underlie the growth and developmental deficits caused by minor changes in cohesin activity. We performed ChIP-chip of Rpb3 (representing total Pol II), Ser2P-Pol II (representing elongating Pol II), and Cdk12 and CycT Pol II kinase components in Mock RNAi-treated and cohesin subunit Rad21 RNAi-treated ML-DmBG3-c2 cells, which revealed that cohesin depletion has a variety of effects on Pol II occupancy and modification, as well as on occupancy of Pol II kinases.
2013-04-24 | E-GEOD-42360 | biostudies-arrayexpress
Project description:Analysis of differential gene expression in third instar Drosophila salivary glands in the absence versus presence of cohesin. ABSTRACT: Developmental abnormalities observed in Cornelia de Lange Syndrome (CdLS) have been genetically linked to mutations in the cohesin machinery. These findings raise the possibility that cohesin, in addition to its canonical function of mediating sister chromatid cohesion, might also be involved in regulating gene expression. We report that cleavage of cohesinM-CM-^Us kleisin subunit in post-mitotic Drosophila salivary glands induces major changes (both up and down) in the transcript levels of many genes. Kinetic analyses of changes in transcript levels upon cohesin cleavage reveal that a subset of genes responds to cohesin cleavage within a few hours. In addition, cohesin binds to most of these loci, suggesting that cohesin is directly regulating their expression. Amongst these genes are several that are regulated by the steroid hormone Ecdysone. Transcripts at EcR and Eip74EF, which encode an Ecdysone Receptor and an Ecdysone-regulated transcription factor, respectively, decline ten-fold within four hours of cohesin cleavage. Cytological visualization of transcription at selected Ecdysone-responsive genes reveals that puffing at Eip74EF ceases within an hour or two of cohesin cleavage, long before any decline in EcR associated with this locus. We conclude that cohesin regulates expression of a distinct set of genes, including those mediating the Ecdysone response. A heat-inducible transgene (hs-TEV) was used to induce TEV in terminally differentiated third instar Drosophila salivary glands expressing either wild type (+ cohesin) or TEV-cleavable myc10-tagged Rad21 protein (Rad21TEV, - cohesin). Total RNA was isolated from + and - cohesin salivary glands 10-12 hours after heat shock induction of TEV (7 independent biological samples each). RNA samples were converted to cDNA, labeled with Cy3 and Cy5 respectively (3x) and vice versa (4x; dye swaps), and hybridized to INDAC FL003 arrays. Analysis of seven arrays, each hybridized to an independently generated sample-pair revealed major differences in transcript levels between + and - cohesin samples.
2010-12-22 | E-GEOD-21844 | biostudies-arrayexpress
Project description:The cohesin complex is a chromosomal component required for sister chromatid cohesion that is conserved from yeast to man. The similarly conserved Nipped-B protein is needed for cohesin to bind to chromosomes. In higher organisms, Nipped-B and cohesin regulate gene expression and development by unknown mechanisms. Using chromatin immunoprecipitation, we find that Nipped-B and cohesin bind to the same sites throughout the entire non-repetitive Drosophila genome. They preferentially bind transcribed regions and overlap with RNA polymerase II. This contrasts sharply with yeast, where cohesin binds almost exclusively between genes. Differences in cohesin and Nipped-B binding between Drosophila cell lines often correlate with differences in gene expression. For example, cohesin and Nipped-B bind the Abd-B homeobox gene in cells in which it is transcribed, but not in cells in which it is silenced. They bind to the Abd-B transcription unit and downstream regulatory region, and thus could regulate both transcriptional elongation and activation. We posit that transcription facilitates cohesin binding, perhaps by unfolding chromatin, and that Nipped-B then regulates gene expression by controlling cohesin dynamics. These mechanisms are likely involved in the etiology of Cornelia de Lange syndrome, in which mutation of one copy of the NIPBL gene encoding the human Nipped B ortholog causes diverse structural and mental birth defects. Keywords: ChIP-chip, cell type comparison, protein comparison
2007-10-18 | GSE9248 | GEO