Identification of topologically associated domains (TADs) in peripheral blood CD34+ cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE188940 | GEO | 2022/09/16
REPOSITORIES: GEO
Similar Datasets
Project description:Genome-scale methods have identified subchromosomal structures so-called topologically associated domains (TADs) that subdivide the genome into discrete regulatory units, establish with their target genes. By re-engineering human duplications at the SOX9 locus in mice combined with 4C-seq and Capture Hi-C experiments, we show that genomic duplications can result in the formation of novel chromatin domains (neo-TADs) and that this process determines their molecular pathology.
2016-10-06 | GSE78105 | GEO
Project description:Genome-scale methods have identified subchromosomal structures so-called topologically associated domains (TADs) that subdivide the genome into discrete regulatory units, establish with their target genes. By re-engineering human duplications at the SOX9 locus in mice combined with 4C-seq and Capture Hi-C experiments, we show that genomic duplications can result in the formation of novel chromatin domains (neo-TADs) and that this process determines their molecular pathology.
2016-10-06 | GSE78072 | GEO
Project description:Genome-scale methods have identified subchromosomal structures so-called topologically associated domains (TADs) that subdivide the genome into discrete regulatory units, establish with their target genes. By re-engineering human duplications at the SOX9 locus in mice combined with 4C-seq and Capture Hi-C experiments, we show that genomic duplications can result in the formation of novel chromatin domains (neo-TADs) and that this process determines their molecular pathology.
2016-10-06 | GSE78067 | 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:The three-dimensional (3D) organization of the genome within the cell nucleus contributes to cell-specific gene expression in different cell types1. High-throughput 3CM-bM-^@M-^Sderived methods have revealed that the genome is segmented into contiguous topologically associating domains (TADs), which help to orchestrate gene expression changes during differentiation and development2-5. Using ChIP-Seq, Hi-C and 3D modelling techniques, we reveal that TADs regulate the rapid gene expression changes induced by progestin in T47D breast cancer cells. In response to the hormone, TADs maintain their borders and operate as discrete regulatory units in which the majority of the genes are either transcriptionally activated or repressed. Additionally, the epigenetic signatures of the TADs are coordinately modified by hormone in correlation with the transcriptional changes. Hormone-induced changes in gene activity and chromatin remodelling are accompanied by structural changes that are distinct for activated or repressed TADs. Integrative 3D modelling revealed that TADs are structurally expanded if active and compacted if repressed, and that this is accompanied by differential changes in accessibility. We thus propose that TADs function as M-bM-^@M-^\regulonsM-bM-^@M-^] to enable spatially proximal genes to be coordinately transcribed in response to hormones. T47D-MTVL human breast cancer cells were incubated with the progestin R5020 for different times at 37M-BM-:C and prepared for ChIP-Seq or Hi-C according published protocols
2014-10-06 | E-GEOD-53463 | biostudies-arrayexpress
Project description:Somatic hypermutation (SHM) introduces point mutations into immunoglobulin (Ig) genes of activated B cells to support the process of antibody affinity maturation but also causes "off-target" mutations in other parts of the genome. We have used sensitive lentiviral SHM reporter vectors and a mutationally active human B cell line to identify dozens of regions of the genome that are intrinsically susceptible to SHM ("hot" regions) and many hundreds of regions that are resistant to SHM ("cold" regions). Hot and cold regions are frequently contained within topologically associated domains (TADs). Comparison of hot and cold TADs reveals that while overall levels of transcription are equal, hot TADs are enriched for NIPBL (a component of the cohesin loader), super enhancers, markers of paused/stalled RNA polymerase 2, and multiple transcription factors implicated in B cell development and targeting of SHM. We demonstrate that at least some hot TADs contain enhancer elements that possess SHM targeting activity and that insertion of a strong Ig SHM-targeting element into a cold TAD renders it hot. Our findings lead to a model for SHM susceptibility involving the cooperative action of cis-acting SHM targeting elements and the dynamic and architectural properties of TADs.
2019-12-04 | GSE139810 | GEO
Project description:Eukaryotic genomes are structurally organized via the formation of multiple loops that create gene expression regulatory units called topologically associating domains (TADs). Here we revealed the KSHV TAD structure at 500 base pair resolution and constructed a 3D KSHV genomic structural model. The latent KSHV genome formed very similar TAD structures among three different naturally infected PEL cell lines. When KSHV reactivation was triggered, genomic loops within TADs were dramatically decreased, while contacts extending outside of TAD borders increased, leading to formation of a larger regulatory unit with a shift from repressive to active compartments (B to A). The 3D structural model proposes that the immediate-early promoter region is localized on the periphery of the 3D viral genome, while highly inducible non-coding RNA regions moved toward the inner space of the structure, resembling the coordination of a "bird cage" during reactivation. Finally, inhibition of the initial burst of lytic gene expression by stop codon insertion in the viral transactivator reduced genomic loops, while supplementing K-Rta expression in trans during establishment of latency attenuated the defect. Our studies suggest that the latent 3D genomic structural information is embedded in the lytic gene transcription program.
2022-06-25 | GSE163696 | GEO
Project description:Transcription-factor binding to cis-regulatory regions regulates the gene expression program of a cell, but occupancy is often a poor predictor of the gene response. Here, we show that glucocorticoid stimulation led to the reorganization of transcriptional coregulators MED1 and BRD4 within topologically associating domains (TADs), resulting in active or repressive gene environments. Indeed, we observed a bias toward the activation or repression of a TAD when their activities were defined by the number of regions gaining and losing MED1 and BRD4 following dexamethasone (Dex) stimulation. Variations in Dex-responsive genes at the RNA levels were consistent with the redistribution of MED1 and BRD4 at the associated cis-regulatory regions. Interestingly, Dex-responsive genes without the differential recruitment of MED1 and BRD4 or binding by the glucocorticoid receptor were found within TADs, which gained or lost MED1 and BRD4, suggesting a role of the surrounding environment in gene regulation. However, the amplitude of the response of Dex-regulated genes was higher when the differential recruitment of the glucocorticoid receptor and transcriptional coregulators was observed, reaffirming the role of transcription factor-driven gene regulation and attributing a lesser role to the TAD environment. These results support a model where a signal-induced transcription factor induces a regionalized effect throughout the TAD, redefining the notion of direct and indirect effects of transcription factors on target genes.
2023-07-19 | GSE226487 | GEO
Project description:Deciphering the rules of genome folding in the cell nucleus is essential in order to understand its functions. Recent Hi-C studies have revealed that the genome is partitioned into topologically associating domains (TADs), which demarcate functional epigenetic domains defined by combinations of specific chromatin marks. However, whether TADs are true physical units in each cell nucleus, or whether they reflect statistical frequencies of measured interactions within cell populations is unclear. Here, using a combination of Hi-C, 3D-Fluorescent In Situ Hybridization (3D-FISH), super-resolution microscopy and polymer modeling, we provide an integrative view of chromatin folding in Drosophila. We observed that repressed TADs form a succession of discrete nano-compartments, interspersed by less condensed active regions. Single-cell analysis revealed a consistent TAD-based physical compartmentalization of the chromatin fiber, with some degree of heterogeneity in intra-TAD conformations and in cis and trans inter-TAD contact events. These results indicate that TADs are fundamental 3D genome units that engage in dynamic higher-order inter-TAD connections. This domain-based architecture is likely to play a major role in regulatory transactions during DNA-dependent processes.
2018-01-03 | GSE99106 | GEO
Project description:Deciphering the rules of genome folding in the cell nucleus is essential in order to understand its functions. Recent Hi-C studies have revealed that the genome is partitioned into topologically associating domains (TADs), which demarcate functional epigenetic domains defined by combinations of specific chromatin marks. However, whether TADs are true physical units in each cell nucleus, or whether they reflect statistical frequencies of measured interactions within cell populations is unclear. Here, using a combination of Hi-C, 3D-Fluorescent In Situ Hybridization (3D-FISH), super-resolution microscopy and polymer modeling, we provide an integrative view of chromatin folding in Drosophila. We observed that repressed TADs form a succession of discrete nano-compartments, interspersed by less condensed active regions. Single-cell analysis revealed a consistent TAD-based physical compartmentalization of the chromatin fiber, with some degree of heterogeneity in intra-TAD conformations and in cis and trans inter-TAD contact events. These results indicate that TADs are fundamental 3D genome units that engage in dynamic higher-order inter-TAD connections. This domain-based architecture is likely to play a major role in regulatory transactions during DNA-dependent processes.
2018-01-03 | GSE99105 | GEO