Discrete genomic domains exhibit co-occurrence of H3K9me3 and H3K27me3 histone modifications throughout Drosophila
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE18572 | GEO | 2009/10/16
REPOSITORIES: GEO
Similar Datasets
Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons. mapping of H3K27me3 histone modification in one MEF cell line (MEFF)
2008-12-22 | E-GEOD-12721 | biostudies-arrayexpress
Project description:The bithorax complex (BX-C) in the fruit fly, Drosophila melanogaster, is a cluster of homeotic genes that determines the identities the body segments. Expression of these genes is governed by cis-regulatory domains, one for each parasegment, which are arranged on the chromosome in the order of the parasegments they affect. Stable repression of these domains depends on the functions of the Polycomb Group, including its ability to methylate lysine 27 of histone H3. To learn whether PcG proteins generate parasegment-specific chromatin signatures, we have used transgenes to mark and isolate nuclei from single parasegments. These nuclei were profiled for histone modifications and chromatin proteins. The H3K27me3 profiles across the BX-C in successive parasegments show a striking “stairstep” pattern that reveals sharp boundaries of the BX-C regulatory domains. The borders of H3K27me3 modification domains are sharp, and align precisely with binding sites for the CCCTC-binding protein (CTCF). H3K27ac is broadly enriched across active domains, in a pattern complementary to K27me3. These findings provide a molecular definition of the homeotic domains, and implicate precisely localized H3K27 modification as a central determinant of segment identity. Nuclei from single parasegments of the Drosophila embryo were isolated and ChIP-seq performed for H3K27me3, CTCF, H3K27ac, H3K4me3, Ph, Pol2, Pc, and Suz12. For each sample, two biological replicates were performed.
2014-08-14 | E-GEOD-55257 | biostudies-arrayexpress
Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons. Keywords: Chip-chip, chromosome 17 wide unbiased mapping unbiased mapping of several histone modifications on chromosome 17 in two independent MEF cell lines
2008-11-23 | E-GEOD-11335 | biostudies-arrayexpress
Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons. Keywords: RNA-chip, chromosome 17 wide expression mapping mouse chromosome 17 wide expression mapping of transcribed genes by hybridization of ds cDNA in two independent MEF cell lines
2008-11-23 | E-GEOD-11337 | biostudies-arrayexpress
Project description:Full title: Complex patterns of genome accessibility discriminate sites of PcG repression, H4K16 acetylation and replication initiation Histone modifications have been proposed to regulate gene expression in part by modulating DNA accessibility and higher-order chromatin structure. However, there is limited direct evidence to support structural differences between euchromatic and heterochromatic fibers in the nucleus. To ask how histone modifications relate to chromatin compaction, we measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint). In the Drosophila genome, we find that accessibility to DNA methylase is variable in a manner that relates to the differential distribution of active and repressive histone modifications. Active promoters are highly permissive to M.SssI activity, yet inactive chromosomal domains decorated with H3 lysine 27 trimethylation are least accessible providing in vivo evidence for Polycomb-mediated chromatin compaction. Conversely, DNA accessibility is increased at active chromosomal regions marked with H4 lysine 16 acetylation and at the dosage-compensated male X chromosome suggesting that Drosophila transcriptional dosage compensation is facilitated by more permissive chromatin structure. Interestingly early replicating chromosomal regions and sites of replication initiation show also higher accessibility linking temporal and spatial control of genome duplication to the structural organization of chromatin. In conclusion, using a novel protocol we generated a comprehensive view of DNA accessibility and uncover different levels of chromatin organization, which are delineated by distinct patterns of posttranslational histone modifications and replication. Keywords: cell type comparison, ChIP-chip, MeDIP-footprint, RNA-seq, ChIP-seq MeDIP-footprint and ChIP-chip: ChIP-chip was performed for H3K4me3, H3K36me2, H3K36me3, H3K27me3, and H3K9me2 in Kc cells. We measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint) in Kc and S2 cells. RNA-seq: cDNA from RNA from Drosophila Kc cells was sequenced using Illumina deep sequencing. Reads were mapped and the abundance of all transcripts was determined. ChIP-seq: PSC ChIP from Drosophila Kc cells was sequenced using Illumina deep sequencing in three lanes. Reads were mapped and the binding profile of PSC was determined.
2010-03-16 | E-GEOD-17697 | biostudies-arrayexpress
Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons.
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Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons. Keywords: RNA-chip, chromosome 17 wide expression mapping
2008-11-24 | GSE11337 | GEO
Project description:Genome wide chromatin maps have shown that spreading repressive histone modifications such as H3K9me3 and H4K20me3 are present on pericentromeric and telomeric repeats and on the inactive X chromosome where H3K27me3 or H3K9me3 alternately modify megabasepair sized domains. However, only a few regions along an autosome of which Homeobox gene clusters are notable examples, have been shown to display spreading of repressive histone modifications. Here we present a ChIP-Chip map of repressive and active histone modifications along mouse Chr.17 in embryonic, fibroblast cells. Our results show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types and their flanking intergenic regions, indicating a negative correlation between H3K27me3 and transcription. However, non-transcribed gene-poor regions also lacked H3K27me3. We therefore performed a low resolution analysis of whole mouse Chr.17 which revealed that H3K27me3 specifically marks megabasepair sized domains that are enriched for genes, SINEs and active histone modifications. These genic H3K27me3 domains alternate with similar sized gene-poor domains that are deficient in active histone modifications, but enriched for LINE and LTR transposons as well as H3K9me3 and H4K20me3. Thus, a mouse autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposons class, which could offer unique chromatin compartments for the specific regulation of genes or the silencing of transposons. Keywords: Chip-chip, chromosome 17 wide unbiased mapping
2008-11-24 | GSE11335 | GEO
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2023-02-06 | GSE215017 | GEO
Project description:In mammalian cells, genes that are in close proximity are coupled transcriptionally: silencing or activating one gene can affect its neighbors. Changes in histone modifications can be involved in driving these transcriptional changes as certain modifications have been shown to spread through reader-writer feedback mechanisms. We investigate this process by recruiting repressive chromatin regulators (KRAB and HDAC4) to dual-gene synthetic reporters with different spacers between the two genes (no spacer- NS and 5kb lambda DNA - 5kb). We then look at changes in both active and repressive chromatin marks by CUT&RUN. We find that silencing by KRAB results in loss of the activating histone 3 lysine acetylation (H3Kac) and histone 3 lysine 4 trimethylation (H3K4me3) marks, as well as a strong increase in the repressive modification histone 3 lysine 9 trimethylation (H3K9me3) across the NS and 5kb reporters both in CHO-K1 and K562 cells. In K562 cells, we also see a larger enrichment of H3K9me3 spanning approximately 50-60 kb beyond the reporter. Silencing by histone deacetylase HDAC4 of the upstream gene can also lead to downstream gene silencing. By CUT&RUN we observe a decrease in acetylation levels, no change in H3K9me3, and a surprising increase in histone 3 lysine 27 trimethylation (H3K27me3) throughout the NS and 5kb reporters. H3K27me3 is associated with polycomb repressive complex 2 (PRC2) and has not been previously reported in direct association with HDAC4; however, our results reveal coordinated transcriptional silencing where removal of acetylation by HDAC4 indirectly led to H3K27me3 deposition, likely by PRC2. These data give insight into how chromatin modifications are associated with changes in expression in a synthetic reporter system.
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