Regions of very low H3K27me3 partition the Drosophila genome into topological domains [HiC-seq]
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE85503 | GEO | 2017/05/02
SECONDARY ACCESSION(S): PRJNA338723
REPOSITORIES: GEO
Similar Datasets
Project description:This SuperSeries is composed of the SubSeries listed below. We have investigated boundaries of topologically associated domains (TADs) in the Drosophila genome and find that they can be identified as domains of very low H3K27me3. The genome-wide H3K27me3 profile partitions into two states; very low H3K27me3 identifies Depleted (D) domains that contain housekeeping genes and their regulators such as the histone acetyltransferase-containing NSL complex, whereas domains containing mid-to-high levels of H3K27me3 (Enriched or E domains) are associated with regulated genes, irrespective of whether they are active or inactive. The D domains correlate with the boundaries of TADs and are enriched in a subset of architectural proteins, particularly Chromator, BEAF-32, and Z4. However, rather than being clustered at the borders of these domains, these proteins bind throughout the H3K27me3-depleted regions and are much more strongly associated with the TSSs of the housekeeping genes than with the H3K27me3 domain boundaries. We suggest that the D domain chromatin state, characterised by very low H3K27me3 and established by housekeeping gene regulators, acts to separate topological domains thereby setting up the domain architecture of the genome.
2017-05-02 | GSE85504 | GEO
Project description:Recent advances enabled by Hi-C technique have unraveled principles of chromosomal folding, which were since linked to many genomic processes. In particular, Hi-C revealed that chromosomes of animals are organized into Topologically Associating Domains (TADs), evolutionary conserved compact chromatin domains that influence gene expression. However, mechanisms that underlie partitioning of the genome into TADs remain poorly understood. To explore principals of TAD folding in Drosophila melanogaster, we performed Hi-C and PolyA+ RNA-seq in four cell lines of various origins (S2, Kc167, DmBG3-c2, and OSC). Contrary to previous studies, we find that regions between TADs (i.e. the inter-TADs and TAD boundaries) in Drosophila are only weakly enriched with the insulator protein dCTCF, while another insulator protein Su(Hw) is preferentially present within TADs. However, Drosophila inter-TADs harbor active chromatin and constitutively transcribed (housekeeping) genes. Accordingly, we find that binding of insulator proteins dCTCF and Su(Hw) predict TAD boundaries much worse than the active chromatin marks (in the minimal case, H3K4me3 and total RNA) do. Moreover, inter-TADs correspond to decompacted interbands of polytene chromosomes, whereas TADs mostly correspond to densely packed bands. Collectively, our results suggest that TADs are condensed chromatin domains depleted in active chromatin marks, separated by regions of active chromatin that cannot be organized into compact structures, possibly due to high levels of histone acetylation. Finally, we test this hypothesis by polymer simulations, and find that TAD partitioning can be explained by different modes of inter-nucleosomal interactions for active and inactive chromatin. Hi-C experiments, PolyA+ RNA profiling and mapping of chromosomal rearrangements in four Drosophila melanogaster cell lines.
2015-10-26 | E-GEOD-69013 | biostudies-arrayexpress
Project description:Eukaryotic chromosomes replicate in a temporal order known as the replication-timing program. In mammals, replication timing is cell type-specific with at least half the genome switching replication timing during development, primarily in units of 400-800 kilobases ('replication domains;), whose positions are preserved in different cell types, conserved between species, and appear to confine long-range effects of chromosome rearrangements. Early and late replication correlate, respectively, with open and closed three-dimensional chromatin compartments identified by high-resolution chromosome conformation capture (Hi-C), and, to a lesser extent, late replication correlates with lamina-associated domains (LADs). Recent Hi-C mapping has unveiled substructure within chromatin compartments called topologically associating domains (TADs) that are largely conserved in their positions between cell types and are similar in size to replication domains. However, TADs can be further sub-stratified into smaller domains, challenging the significance of structures at any particular scale.Moreover, attempts to reconcile TADs and LADs to replication-timing data have not revealed a common, underlying domain structure. Here we localize boundaries of replication domains to the early-replicating border of replication-timing transitions and map their positions in 18 human and 13 mouse cell types. We demonstrate that, collectively, replication domain boundaries share a near one-to-one correlation with TAD boundaries, whereas within a cell type, adjacent TADs that replicate at similar times obscure replication domain boundaries, largely accounting for the previously reported lack of alignment. Moreover, cell-type-specific replication timing of TADs partitions the genome into two large-scale sub-nuclear compartments revealing that replication-timing transitions are indistinguishable from late-replicating regions in chromatin composition and lamina association and accounting for the reduced correlation of replication timing to LADs and heterochromatin. Our results reconcile cell-type-specific sub-nuclear compartmentalization and replication timing with developmentally stable structural domains and offer a unified model for large-scale chromosome structure and function.
2014-11-20 | GSE51334 | GEO
Project description:We report the application of Chromosome Conformation Capture Carbon-copy (5C) to a 4.5 Mb stretch of the mouse X chromosome encompassing the X inactivation center locus. We uncover a series of discrete 200kb-1Mb topologically associating domains (TADs). These align with several domain-wide epigenomic features as well as co-regulated gene clusters. 5C analysis in EED and G9A mutants reveal that this segmental organisation in TADs does not relie on the underlying H3K27me3 or H3K9me2 blocks. Deletion of a boundary between two TADs leads to ectopic chromosomal contacts between them. Analysis of mESCs, mNPCs and MEFs suggest that the positioning of TADs on the chromosome is stable during cell differentiation though their internal organisation changes. Comparison of male (XY) and female (XX) differentiated cells highlights that the long-range chromosomal contacts within TADs are dampened on the inactive X compared to the active X. 5C oligonucleotides were designed around HindIII restriction site following an alternative scheme
2012-04-11 | E-GEOD-35721 | biostudies-arrayexpress
Project description:Recent advances enabled by Hi-C technique have unraveled principles of chromosomal folding, which were since linked to many genomic processes. In particular, Hi-C revealed that chromosomes of animals are organized into Topologically Associating Domains (TADs), evolutionary conserved compact chromatin domains that influence gene expression. However, mechanisms that underlie partitioning of the genome into TADs remain poorly understood. To explore principals of TAD folding in Drosophila melanogaster, we performed Hi-C and PolyA+ RNA-seq in four cell lines of various origins (S2, Kc167, DmBG3-c2, and OSC). Contrary to previous studies, we find that regions between TADs (i.e. the inter-TADs and TAD boundaries) in Drosophila are only weakly enriched with the insulator protein dCTCF, while another insulator protein Su(Hw) is preferentially present within TADs. However, Drosophila inter-TADs harbor active chromatin and constitutively transcribed (housekeeping) genes. Accordingly, we find that binding of insulator proteins dCTCF and Su(Hw) predict TAD boundaries much worse than the active chromatin marks (in the minimal case, H3K4me3 and total RNA) do. Moreover, inter-TADs correspond to decompacted interbands of polytene chromosomes, whereas TADs mostly correspond to densely packed bands. Collectively, our results suggest that TADs are condensed chromatin domains depleted in active chromatin marks, separated by regions of active chromatin that cannot be organized into compact structures, possibly due to high levels of histone acetylation. Finally, we test this hypothesis by polymer simulations, and find that TAD partitioning can be explained by different modes of inter-nucleosomal interactions for active and inactive chromatin.
2015-10-26 | GSE69013 | GEO
Project description:Regions of very low H3K27me3 partition the Drosophila genome into topological domains
| PRJNA338669 | ENA
Project description:Chromatin insulators are involved in transcription regulation and long-range chromatin contacts. In Drosophila the Boundary Element-Associated Factor Of 32kD (BEAF-32) binds to promoters of housekeeping genes and the boundaries of Topological Associated Domains (TAD) and is involved in the regulation of long-range targets by mechanisms that remain incompletely understood. Here we show that Relative-Of-WOC (ROW), which is part of the Heterochromatin Protein 1c (HP1c) complex, is essential for the long-range transcription regulation mediated by BEAF-32. We found that ROW physically interacts with the insulator complex proteins BEAF-32 and Chromator, as well as with HP1c, HP1b, and Without Children (WOC). Moreover, we found that ROW binds AT-rich sequences flanked by BEAF-32 motifs, which are located at promoters of housekeeping genes and in TAD boundaries. In agreement with these results, the genome distribution of ROW strongly correlated with BEAF-32 and WOC, but at a lower level with HP1c and HP1b. Knockdown of row resulted in downregulation of genes that are long-range targets of BEAF-32, are indirectly bound by BEAF-32 and ROW, and enriched with factors associated with RNA polymerase II pausing. These results suggest that ROW and BEAF-32 are involved in the recruitment of protein complexes required for transcription activation and long-range contacts between promoters of housekeeping and inducible genes.
2022-07-14 | GSE169413 | GEO
Project description:Chromatin insulators are involved in transcription regulation and long-range chromatin contacts. In Drosophila the Boundary Element-Associated Factor Of 32kD (BEAF-32) binds to promoters of housekeeping genes and the boundaries of Topological Associated Domains (TAD) and is involved in the regulation of long-range targets by mechanisms that remain incompletely understood. Here we show that Relative-Of-WOC (ROW), which is part of the Heterochromatin Protein 1c (HP1c) complex, is essential for the long-range transcription regulation mediated by BEAF-32. We found that ROW physically interacts with the insulator complex proteins BEAF-32 and Chromator, as well as with HP1c, HP1b, and Without Children (WOC). Moreover, we found that ROW binds AT-rich sequences flanked by BEAF-32 motifs, which are located at promoters of housekeeping genes and in TAD boundaries. In agreement with these results, the genome distribution of ROW strongly correlated with BEAF-32 and WOC, but at a lower level with HP1c and HP1b. Knockdown of row resulted in downregulation of genes that are long-range targets of BEAF-32, are indirectly bound by BEAF-32 and ROW, and enriched with factors associated with RNA polymerase II pausing. These results suggest that ROW and BEAF-32 are involved in the recruitment of protein complexes required for transcription activation and long-range contacts between promoters of housekeeping and inducible genes.
2022-07-14 | GSE169410 | GEO
Project description:Chromatin insulators are involved in transcription regulation and long-range chromatin contacts. In Drosophila the Boundary Element-Associated Factor Of 32kD (BEAF-32) binds to promoters of housekeeping genes and the boundaries of Topological Associated Domains (TAD) and is involved in the regulation of long-range targets by mechanisms that remain incompletely understood. Here we show that Relative-Of-WOC (ROW), which is part of the Heterochromatin Protein 1c (HP1c) complex, is essential for the long-range transcription regulation mediated by BEAF-32. We found that ROW physically interacts with the insulator complex proteins BEAF-32 and Chromator, as well as with HP1c, HP1b, and Without Children (WOC). Moreover, we found that ROW binds AT-rich sequences flanked by BEAF-32 motifs, which are located at promoters of housekeeping genes and in TAD boundaries. In agreement with these results, the genome distribution of ROW strongly correlated with BEAF-32 and WOC, but at a lower level with HP1c and HP1b. Knockdown of row resulted in downregulation of genes that are long-range targets of BEAF-32, are indirectly bound by BEAF-32 and ROW, and enriched with factors associated with RNA polymerase II pausing. These results suggest that ROW and BEAF-32 are involved in the recruitment of protein complexes required for transcription activation and long-range contacts between promoters of housekeeping and inducible genes.
2022-07-14 | GSE169408 | GEO
Project description:Chromatin insulators are involved in transcription regulation and long-range chromatin contacts. In Drosophila the Boundary Element-Associated Factor Of 32kD (BEAF-32) binds to promoters of housekeeping genes and the boundaries of Topological Associated Domains (TAD) and is involved in the regulation of long-range targets by mechanisms that remain incompletely understood. Here we show that Relative-Of-WOC (ROW), which is part of the Heterochromatin Protein 1c (HP1c) complex, is essential for the long-range transcription regulation mediated by BEAF-32. We found that ROW physically interacts with the insulator complex proteins BEAF-32 and Chromator, as well as with HP1c, HP1b, and Without Children (WOC). Moreover, we found that ROW binds AT-rich sequences flanked by BEAF-32 motifs, which are located at promoters of housekeeping genes and in TAD boundaries. In agreement with these results, the genome distribution of ROW strongly correlated with BEAF-32 and WOC, but at a lower level with HP1c and HP1b. Knockdown of row resulted in downregulation of genes that are long-range targets of BEAF-32, are indirectly bound by BEAF-32 and ROW, and enriched with factors associated with RNA polymerase II pausing. These results suggest that ROW and BEAF-32 are involved in the recruitment of protein complexes required for transcription activation and long-range contacts between promoters of housekeeping and inducible genes.
2022-07-14 | GSE169407 | GEO