Cooperativity, specificity and evolutionary stability of Polycomb targeting in Drosophila
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE61471 | GEO | 2014/10/20
SECONDARY ACCESSION(S): PRJNA261249
REPOSITORIES: GEO
Similar Datasets
Project description:We report the evolutionary behaviour of Polycomb group proteins, their recruitment factors and their underlying sequences by performing ChIP-seq analysis in 4-5 different Drosophila species (GSE60428) and HiC analysis in Drosophila melanogaster. We demonstrate an extremely high conservation of Polycomb repressive domains across Drosophila species We validate few cases of PRE divergence that shows that cis-driven PRE evolution is a rare event. We further show that PHO recruitment to Polycomb domains is evolutionarily robust to motif changes and that PRC1 stabilizes binding of its key recruiter HiC experiments in wild type drosophila embryos
2014-10-20 | E-GEOD-61471 | biostudies-arrayexpress
Project description:We report the evolutionary behaviour of Polycomb group proteins, their recruitment factors and their underlying sequences by performing ChIP-seq analysis in 4-5 different Drosophila species. We demonstrate an extremely high conservation of Polycomb repressive domains across Drosophila species We validate few cases of PRE divergence that shows that cis-driven PRE evolution is a rare event. We further show that PHO recruitment to Polycomb domains is evolutionarily robust to motif changes and that PRC1 stabilizes binding of its key recruiter ChIP-seq analysis of histone marks and chromatin associated factors across 4-5 Drosophila species
2014-10-20 | E-GEOD-60428 | biostudies-arrayexpress
Project description:We report the evolutionary behaviour of Polycomb group proteins, their recruitment factors and their underlying sequences by performing ChIP-seq analysis in 4-5 different Drosophila species. We demonstrate an extremely high conservation of Polycomb repressive domains across Drosophila species We validate few cases of PRE divergence that shows that cis-driven PRE evolution is a rare event. We further show that PHO recruitment to Polycomb domains is evolutionarily robust to motif changes and that PRC1 stabilizes binding of its key recruiter
2014-10-20 | GSE60428 | GEO
Project description:Polycomb group (PcG) proteins maintain the silenced state of key developmental genes in animals, but how these proteins are recruited to specific regions of the genome is still poorly understood. In Drosophila, PcG proteins are recruited to Polycomb response elements (PREs) that include combinations of sites for sequence specific DNA binding “PcG recruiters,” including Pho, Cg, and Spps. To understand their roles in PcG recruitment, we compared Pho-, Cg-, and Spps-binding sites against H3K27me3 and key PcG proteins by ChIP-seq in wild-type and mutant third instar larvae. H3K27me3 in canonical Polycomb domains is decreased after the reduction of any recruiter. Reduction of Spps and Pho, but not Cg, causes the redistribution of H3K27me3 to heterochromatin. Regions with dramatically depleted H3K27me3 after Spps knockout are usually accompanied by decreased Pho binding, suggesting their cooperative binding. PcG recruiters, the PRC2 component E(z), and the PRC1 components Psc and Ph cobind thousands of active genes outside of H3K27me3 domains. This study demonstrates the importance of distinct PcG recruiters for the establishment of unique Polycomb domains. Different PcG recruiters can act both cooperatively and independently at specific PcG target genes, highlighting the complexity and diversity of PcG recruitment mechanisms.
2018-03-07 | GSE102339 | GEO
Project description:The Polycomb group (PcG) proteins are fundamental epigenetic regulators that control the repressive state of target genes in multicellular organisms. One of the open questions is defining the mechanisms of PcG recruitment to chromatin. In Drosophila, the crucial role in PcG recruitment is thought to belong to DNA-binding proteins associated with Polycomb response elements (PREs). However, current data suggests that not all PRE-binding factors have been identified. Here, we report the identification of the transcription factor Crooked legs (Crol) as a novel PcG recruiter. Crol is a C2H2-type Zinc Finger protein that directly binds to poly(G)-rich DNA sequences. Mutation of Crol binding sites as well as crol CRISPR/Cas9 knockout diminish the repressive activity of PREs in transgenes. Like other PRE-DNA binding proteins, Crol co-localizes with PcG proteins inside and outside of H2K27me3 domains. Crol knockout impairs the recruitment of the PRC1 subunit Polyhomeotic and the PRE-binding protein Combgap at a subset of sites. The decreased binding of PcG proteins is accompanied by dysregulated transcription of target genes. Overall, our study identified Crol as a new important player in PcG recruitment and epigenetic regulation.
2023-04-19 | GSE202870 | GEO
Project description:The Polycomb group (PcG) proteins are fundamental epigenetic regulators that control the repressive state of target genes in multicellular organisms. One of the open questions is defining the mechanisms of PcG recruitment to chromatin. In Drosophila, the crucial role in PcG recruitment is thought to belong to DNA-binding proteins associated with Polycomb response elements (PREs). However, current data suggests that not all PRE-binding factors have been identified. Here, we report the identification of the transcription factor Crooked legs (Crol) as a novel PcG recruiter. Crol is a C2H2-type Zinc Finger protein that directly binds to poly(G)-rich DNA sequences. Mutation of Crol binding sites as well as crol CRISPR/Cas9 knockout diminish the repressive activity of PREs in transgenes. Like other PRE-DNA binding proteins, Crol co-localizes with PcG proteins inside and outside of H2K27me3 domains. Crol knockout impairs the recruitment of the PRC1 subunit Polyhomeotic and the PRE-binding protein Combgap at a subset of sites. The decreased binding of PcG proteins is accompanied by dysregulated transcription of target genes. Overall, our study identified Crol as a new important player in PcG recruitment and epigenetic regulation.
2023-04-19 | GSE202832 | GEO
Project description:Polycomb group (PcG) proteins maintain the silenced state of key developmental genes, but how these proteins are recruited to specific regions of the genome is still not completely understood. In Drosophila, PcG proteins are recruited to Polycomb response elements (PREs) comprised of a flexible array of sites for sequence-specific DNA binding proteins, “PcG recruiters”, including Pho, Spps, Cg, GAF and many others. Pho is thought to play a central role in PcG recruitment. Early data showed that mutation of Pho binding sites in PREs in transgenes abrogated the ability of those PREs to repress gene expression. In contrast, genome-wide experiments in pho mutants or by Pho knockdown showed that PcG proteins can bind to PREs in the absence of Pho. Here we directly addressed the importance of Pho binding sites in two engrailed (en) PREs at the endogenous locus and in transgenes. Our results show that Pho binding sites are required for PRE activity in transgenes with a single PRE. In a transgene, two PREs together lead to stronger, more stable repression and confer some resistance to the loss of Pho binding sites. Making the same mutation in Pho binding sites has little effect on PcG-protein binding at the endogenous en gene. Overall, our data support the model that Pho is important for PcG binding but emphasize how multiple PREs and chromatin environment increase the ability of PREs to function in the absence of Pho.
2023-05-08 | GSE227553 | GEO
Project description:Background Antennae of fruit flies are the major organs responsible for detecting environmental volatiles, e.g., egg-laying substrates. An adult antenna contains many sensilla full of olfactory sensory neurons, where olfactory receptor (Or) genes are expressed. Each sensory neuron only expresses up to three receptors, making it difficult to estimate expression levels by conventional methods. In this study, we applied Illumina RNA sequencing (RNA-seq) to study the expression levels of Or and other genes in fly antennae. Results RNA from approximately 1,200 pairs of adult antennae from each sex of Drosophila melanogaster was used to obtain the antennal transcriptome of each sex. We detected approximately 12,000 genes expressed in antennae of either sex. The most highly expressed genes included pheromone-binding genes, transmembrane transporter genes, and sensory reception genes. Among the 61 annotated Or genes, we observed 53 and 54 genes (approximately 90%) expressed (fragments per kilobase of exon per million fragments mapped (FPKM) > 0.05) in male and female antennae, respectively; approximately 25 genes were expressed with FPKM > 15. Compared to previous studies, which extracted RNA from the whole body or head and used microarrays, antenna-specific transcriptomes obtained by RNA-seq provided more reliable estimates of gene expression levels and revealed many lowly expressed genes. Ninty-one genes, including one odorant-binding protein (Obp) gene and four Or genes, were differentially expressed between male and female antennae. These sexually biased genes were enriched on the X chromosome and showed enrichment in different gene ontology categories for male and female flies. The present and previous data together suggest that a gene family with putative immune response functions is related to pheromone detection and involved in the courtship behavior of male flies. Conclusions Tissue-specific RNA-seq is powerful for detecting lowly expressed genes. Our study provides new insight into the expression of olfactory-related genes in Drosophila antennae.ophila sechellia relies exclusively on the fruits of Morinda citrifolia, which are toxic to most insects, including its sibling species D. melanogaster and D. simulans. Although several odorant binding protein (Obp) genes and olfactory receptor (Or) genes were suggested to be associated with the D. sechellia host shift, a broad view of how chemosensory genes have contributed to this shift is still lacking. We therefore studied the antennal transcriptomes, the main organ responsible for detecting food resource and oviposition, of D. sechellia and its two sibling species. We wanted to know whether gene expression, particularly chemosensory genes, has diverged between D. sechellia and its two sibling species. Using a very stringent definition of differential gene expression, we found 147 genes (including 11 chemosensory genes) were up-regulated while only 81 genes (including 5 chemosensory genes) were down-regulated in D. sechellia. Interestingly, Obp50a exhibited the highest up-regulation, a ~100 fold increase, and Or85c – previously reported to be a larva-specific gene– showed ~20 fold up-regulation in D. sechellia. Furthermore, Ir84a, proposed to be associated with male courtship behavior, is significantly up-regulated in D. sechellia. We also found expression divergence in most of the receptor gene families between D. sechellia and the two sibling species. Our observations suggest that the host shift of D. sechellia is associated with expression profile divergence in all chemosensory gene families and is achieved mostly by up-regulation of chemosensory genes.the evolutionary behaviour of Polycomb group proteins, their recruitment factors and their underlying sequences by performing ChIP-seq analysis in 4-5 different Drosophila species (GSE60428) and HiC analysis in Drosophila melanogaster. We demonstrate an extremely high conservation of Polycomb repressive domains across Drosophila species We validate few cases of PRE divergence that shows that cis-driven PRE evolution is a rare event. We further show that PHO recruitment to Polycomb domains is evolutionarily robust to motif changes and that PRC1 stabilizes binding of its key recruiter
2017-06-01 | GSE99545 | GEO
Project description:Context dependent role of Pho binding sites in Polycomb complex recruitment in Drosophila
| PRJNA945490 | ENA
Project description:Drosophila Polycomb group (PcG) and Trithorax group (TrxG) proteins are responsible for the maintenance of stable transcription patterns of many developmental regulators, such as the homeotic genes. We have used a ChIP-on- Chip approach to map the distribution of several PcG/TrxG proteins as well as histone modifications across the two homeotic complexes ANT-C and BX-C. Our data indicate the colocalization of the Polycomb repressive complex 1 (PRC1) with Trx and the DNA binding protein Pleiohomeotic (Pho) at discrete sequence elements as well as significant chromatin assembly differences in active and inactive regions. Trx binds to the promoters of active genes and noncoding transcripts. Most strikingly, in the active state Pho covers extended chromatin domains over many kilobases. The histone modifications investigated, seem to be mutually exclusive, with histone H3 trimethylated at lysine 27 covering inactive chromatin domains whereas hyperacetylated histone H4 is present only at active genes. Keywords: ChIP-chip, cell line comparison
2007-09-25 | GSE7031 | GEO