Three-dimensional folding and functional organization principles of the Drosophila genome
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE34453 | GEO | 2012/01/20
SECONDARY ACCESSION(S): PRJNA151197
REPOSITORIES: GEO
Similar Datasets
Project description:Chromosomes are the physical realization of genetic information and thus form the basis for its reading, hindering and propagation. Here we present a high-resolution chromosomal contact map derived from a new genome-wide chromosome conformation capture approach (a simplified version of the Hi-C method) applied to Drosophila embryonic nuclei. The data show that the entire genome is linearly partitioned into well-demarcated physical domains that overlap extensively with active and repressive epigenetic marks. Chromosomal contacts are hierarchically organized between domains. Global modeling of compaction and clustering of domains show that inactive domains are condensed and confined to their chromosomal territories, while active domains reach out of the territory to form remote intra- and inter-chromosomal contacts. One pilot sample, comprising seven paired-end Illumina GA-II lanes; one deep-sequenced sample, comprising seven paired-end Illumina HiSeq lanes
2012-01-20 | E-GEOD-34453 | biostudies-arrayexpress
Project description:Chromosomes are folded into highly compacted structures to accommodate physical constraints within nuclei and to regulate access to genomic information. Recently, global mapping of pairwise contacts showed that loops anchoring topological domains (TADs), are highly conserved between cell types and species. Whether pairwise loops synergize to form higher order structures is still unclear. Here we develop a conformation capture approach to study higher order organization using chromosomal walks (C-walks) that link multiple genomic loci together into proximity chains. The data captured a hierarchical chromosomal structure at varying scales. Inter-chromosomal contacts constitute only 7-10% of the pairs and are restricted by the TAD structure of the interfacing chromosomes. About half of the C-walks stay within one chromosome, and almost half of these are restricted to intra-TAD spaces. Analysis of nested topological motifs suggests hierarchical chromosomal structure is present also within TADs. Targeted analysis of thousands of 3-walks anchored at strongly expressed genes support nested, rather than hub-like, chromosomal topology at active loci. Polycomb-repressed HOX domains are shown by the same approach to form synergistic hubs. Together, the data suggest that chromosomal territories, TADs, and intra-TAD loops are primarily driven by nested, possibly dynamic, pairwise contacts.
2016-02-04 | GSE77553 | GEO
Project description:Large-scale chromosome structure and spatial nuclear arrangement have been linked to control of gene expression and DNA replication and repair. Genomic techniques based on chromosome conformation capture assess contacts for millions of loci simultaneously, but do so by averaging chromosome conformations from millions of nuclei. Here we introduce single cell Hi-C, combined with genome-wide statistical analysis and structural modeling of single copy X chromosomes, to show that individual chromosomes maintain domain organisation at the megabase scale, but show variable cell-to-cell chromosome territory structures at larger scales. Despite this structural stochasticity, localisation of active gene domains to boundaries of territories is a hallmark of chromosomal conformation, affecting most domains in most nuclei. Single cell Hi-C data bridge current gaps between genomics and microscopy studies of chromosomes, demonstrating how modular organisation underlies dynamic chromosome structure, and how this structure is probabilistically linked with genome activity patterns. Mouse Th1 single-cell Hi-C maps were produced and paired-end sequenced. 10 single-cell samples and a multi-sample pool together with a population Hi-C sample are included.
2013-09-26 | E-GEOD-48262 | biostudies-arrayexpress
Project description:Large-scale chromosome structure and spatial nuclear arrangement have been linked to control of gene expression and DNA replication and repair. Genomic techniques based on chromosome conformation capture assess contacts for millions of loci simultaneously, but do so by averaging chromosome conformations from millions of nuclei. Here we introduce single cell Hi-C, combined with genome-wide statistical analysis and structural modeling of single copy X chromosomes, to show that individual chromosomes maintain domain organisation at the megabase scale, but show variable cell-to-cell chromosome territory structures at larger scales. Despite this structural stochasticity, localisation of active gene domains to boundaries of territories is a hallmark of chromosomal conformation, affecting most domains in most nuclei. Single cell Hi-C data bridge current gaps between genomics and microscopy studies of chromosomes, demonstrating how modular organisation underlies dynamic chromosome structure, and how this structure is probabilistically linked with genome activity patterns.
2013-09-26 | GSE48262 | GEO
Project description:Eukaryotic chromosomes are partitioned into topologically associating domains (TADs) that are demarcated by distinct insulator-binding proteins (IBPs) in Drosophila. Whether IBPs regulate specific long-range contacts and how this may impact gene expression remains unclear. Here we identify ‘indirect peaks’ of multiple IBPs, that represent their distant sites of interactions through long-range contacts. Indirect peaks depend on protein-protein interactions among multiple IBPs and their common co-factors, including CP190, as confirmed by high-resolution analyses of long-range contacts. Mutant IBPs unable to interact with CP190 impair long-range contacts as well as the expression of hundreds of distant genes that are specifically flanked by indirect peaks. Regulation of distant genes strongly correlates with RNAPII pausing, highlighting how this key transcriptional stage may trap insulator-based long-range interactions. Our data illustrate how indirect peaks may decipher gene regulatory networks through specific long-range interactions. Binding profiles of Beaf-32 in Drosophila S2 cells by ChIP-Seq (Illumina)
2014-02-01 | E-GEOD-52962 | biostudies-arrayexpress
Project description:Eukaryotic chromosomes are partitioned into topologically associating domains (TADs) that are demarcated by distinct insulator-binding proteins (IBPs) in Drosophila. Whether IBPs regulate specific long-range contacts and how this may impact gene expression remains unclear. Here we identify M-bM-^@M-^Xindirect peaksM-bM-^@M-^Y of multiple IBPs, that represent their distant sites of interactions through long-range contacts. Indirect peaks depend on protein-protein interactions among multiple IBPs and their common co-factors, including CP190, as confirmed by high-resolution analyses of long-range contacts. Mutant IBPs unable to interact with CP190 impair long-range contacts as well as the expression of hundreds of distant genes that are specifically flanked by indirect peaks. Regulation of distant genes strongly correlates with RNAPII pausing, highlighting how this key transcriptional stage may trap insulator-based long-range interactions. Our data illustrate how indirect peaks may decipher gene regulatory networks through specific long-range interactions. mRNA profiles of stably transfected Drosophila S2 cell lines expressing Wild-Type or Mutant Beaf by RNASeq (Illumina/TruSeq), in triplicates
2014-02-01 | E-GEOD-52884 | biostudies-arrayexpress
Project description:Eukaryotic chromosomes are partitioned into topologically associating domains (TADs) that are demarcated by distinct insulator-binding proteins (IBPs) in Drosophila. Whether IBPs regulate specific long-range contacts and how this may impact gene expression remains unclear. Here we identify ‘indirect peaks’ of multiple IBPs, that represent their distant sites of interactions through long-range contacts. Indirect peaks depend on protein-protein interactions among multiple IBPs and their common co-factors, including CP190, as confirmed by high-resolution analyses of long-range contacts. Mutant IBPs unable to interact with CP190 impair long-range contacts as well as the expression of hundreds of distant genes that are specifically flanked by indirect peaks. Regulation of distant genes strongly correlates with RNAPII pausing, highlighting how this key transcriptional stage may trap insulator-based long-range interactions. Our data illustrate how indirect peaks may decipher gene regulatory networks through specific long-range interactions. Binding profiles of CP190 in stably transfected Drosophila S2 cell lines expressing in Wild-Type Beaf (Control) or Mutant Beaf by ChIP-Seq (Illumina)
2014-02-01 | E-GEOD-52886 | biostudies-arrayexpress
Project description:The mechanisms responsible for the establishment of physical domains in metazoan chromosomes are poorly understood. Here we find that physical domains in Drosophila chromosomes are demarcated at regions of active transcription and high gene density that are enriched for transcription factors and specific combinations of insulator proteins. Physical domains contain different types of chromatin defined by the presence of specific proteins and epigenetic marks, with active chromatin preferentially located at the borders and silenced chromatin in the interior. Domain boundaries participate in long-range interactions that may contribute to the clustering of regions of active or silenced chromatin in the nucleus. Analysis of transgenes suggests that chromatin is more accessible and permissive to transcription at the borders than inside domains, independent of the presence of active or silencing histone modifications. These results suggest that the higher-order physical organization of chromatin may impose an additional level of regulation over classical epigenetic marks.
2012-10-04 | GSE38468 | GEO
Project description:The mechanisms responsible for the establishment of physical domains in metazoan chromosomes are poorly understood. Here we find that physical domains in Drosophila chromosomes are demarcated at regions of active transcription and high gene density that are enriched for transcription factors and specific combinations of insulator proteins. Physical domains contain different types of chromatin defined by the presence of specific proteins and epigenetic marks, with active chromatin preferentially located at the borders and silenced chromatin in the interior. Domain boundaries participate in long-range interactions that may contribute to the clustering of regions of active or silenced chromatin in the nucleus. Analysis of transgenes suggests that chromatin is more accessible and permissive to transcription at the borders than inside domains, independent of the presence of active or silencing histone modifications. These results suggest that the higher-order physical organization of chromatin may impose an additional level of regulation over classical epigenetic marks. We carried out Hi-C experiment using HindIII on Kc167 cells and generate two libraries separately. One library was sequenced once more as technical replicates (TR1 and TR2), the other library was sequenced as biological replicate (BR). processed files contain the following: Column 1: chromosome ID in which the first read in a pair locates Column 2: coordinate of the first read Column 3: chromosome ID in which the second read in a pair locates Column 4: coordinate of the second read
2012-10-04 | E-GEOD-38468 | biostudies-arrayexpress
Project description:To ensure proper gene regulation within constrained nuclear space, chromosomes facilitate access to transcribed regions, while compactly packaging all other information. Recent studies revealed that chromosomes are organized into megabase-scale domains that demarcate active and inactive genetic elements, suggesting that compartmentalization is important for genome function. Here we show that very specific long-range interactions are anchored by cohesin/CTCF sites, but not cohesin-only or CTCF-only sites, to form a hierarchy of chromosomal loops. These loops demarcate topological domains and form intricate internal structures within them. Post-mitotic nuclei deficient for functional cohesin exhibit global architectural changes associated with loss of cohesin/CTCF contacts and relaxation of topological domains. Transcriptional analysis shows that this cohesin-dependent perturbation of domain organization leads to widespread gene deregulation of both cohesin-bound and non-bound genes. Our data thereby support a role for cohesin in the global organization of domain structure and suggest that domains function to stabilize the transcriptional programs within them. Hi-C, ChIP-Seq and RNA-Seq experiments were conducted in mouse neural stem cells and mouse astrocytes
2013-12-11 | E-GEOD-49017 | biostudies-arrayexpress