Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

CLoops2: a full-stack comprehensive analytical tool for chromatin interactions

ABSTRACT: Investigating chromatin interactions between regulatory regions such as enhancer and promoter elements is pivotal for a deeper understanding of gene expression regulation. The emerging 3D mapping technologies focusing on enriched signals such as Hi-TrAC/Trac-looping and HiChIP, compared to Hi-C, reduce the sequencing cost, and provide higher interaction resolution for cis-regulatory elements and more comprehensive information such as chromatin accessibility. A robust pipeline is needed for the comprehensive interpretation of these data, especially for loop-centric analysis. Therefore, we have developed a new versatile tool named cLoops2 for the full-stack analysis of the 3D chromatin interaction data. cLoops2 consists of core modules of peak-calling, loop-calling, differentially enriched loops calling and loops annotation. Additionally, it also contains multiple modules to carry out interaction resolution estimation, data similarity estimation, features quantification and aggregation analysis, and visualization. cLoops2 with documentation and example data are open source and freely available at GitHub: https://github.com/YaqiangCao/cLoops2

ORGANISM(S): Homo sapiens

PROVIDER: GSE179010 | GEO | 2021/11/29

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

Chromatin extrusion explains key features of loop and domain formation in wild-type and engineered genomes

Project description:We recently used in situ Hi-C to create kilobase-resolution 3D maps of mammalian genomes. Here, we combine these with new Hi-C, microscopy, and genome-editing experiments to study the physical structure of chromatin fibers, domains, and loops. We find that the observed contact domains are inconsistent with the equilibrium state for an ordinary condensed polymer. Combining Hi-C data and novel mathematical theorems, we show that contact domains are also not consistent with a fractal globule. Instead, we use physical simulations to study two models of genome folding. In one, intermonomer attraction during polymer condensation leads to formation of an anisotropic "tension globule." In the other, CTCF and cohesin act together to extrude loops during interphase. Both models are consistent with the observed contact domains and with the observation that contact domains tend to form inside loops. However, the extrusion model explains a far wider array of observations, such as why loops tend not to overlap and why the CTCF-binding motifs at pairs of loop anchors lie in the convergent orientation. Finally, we perform 13 genome-editing experiments examining the effect of altering CTCF-binding sites on chromatin folding. The convergent rule correctly predicts the affected loop in every case. Moreover, the extrusion model accurately predicts in silico the 3D maps resulting from each experiment using only the location of CTCF-binding sites in the WT. Thus, we show that it is possible to disrupt, restore, and move loops and domains using targeted mutations as small as a single base pair. in situ Hi-C and HYbrid Capture Hi-C (Hi-C2) were used to probe the three-dimensional structure of the genome in two different human cell types before and after genome editing.

2015-10-23 | E-GEOD-74072 | biostudies-arrayexpress

Trac-looping measures genome structure and chromatin accessibility

Project description:Interaction between different chromatin regions plays critical roles in genome organization and regulation of transcription. Existing technologies of analyzing genome-wide chromatin interactions rely on in vitro proximity-based ligation of interacting chromatin fragments and thus are prone to potential artifacts. We now report a novel technique, Transposase-mediated Analysis of Chromatin loops (TrAC-loop), for detection of genome-wide chromatin interactions between regulatory regions. With this technique, a bivalent oligonucleotide linker is inserted between two interacting chromatin regions such that the distant interacting chromatin regions can be directly amplified by PCR and thus avoids the prior chromatin fragmentation and subsequent error-prone re-ligation steps. TrAC-loop selectively targets accessible regions, which effectively reduces the sequencing cost for detecting promoter-enhancer interactions at high resolution. Application of TrAC-loop to human CD4+ T cells reveals a substantial reorganization of enhancer-promoter interaction associated with changes in gene expression upon TCR stimulation.

2018-07-12 | GSE87254 | GEO

Hi-TrAC Detects Active Sub-TADs and Reveals Internal Organizations of Super-Enhancers

Project description:Eukaryotic genome spatial folding plays a key role in genome function. Decoding the principles and dynamics of 3D genome organization depends on improving technologies to achieve higher resolution. Chromatin domains have been suggested as regulatory micro-environments, whose identification is crucial to understand the genome architecture. We report here that our recently developed method, Hi-TrAC, which specializes in detecting chromatin loops among genomic accessible regulatory regions, allows us to examine active domains with limited sequencing depths at a high resolution. Hi-TrAC can detect active sub-TADs with a median size of 100kb, most of which harbor one or two cell specifically expressed genes and regulatory elements such as super-enhancers organized into nested interaction domains. These active sub-TADs are characterized by highly enriched signals of histone mark H3K4me1 and chromatin-binding proteins, including Cohesin complex. We show that knocking down core subunit of the Cohesin complex using shRNAs in human cells or decreasing the H3K4me1 modification by deleting the H3K4 methyltransferase Mll4 gene in mouse Th17 cells disrupted the sub-TADs structure. In summary, Hi-TrAC serves as a compatible and highly responsive approach to studying dynamic changes of active sub-TADs, allowing us more explicit insights into delicate genome structures and functions.

2023-04-25 | GSE208085 | GEO

MCM complexes are barriers that restrict cohesin-mediated loop extrusion [RNA-Seq]

Project description:Eukaryotic genomes are compacted into loops and topologically associating domains (TADs), which contribute to transcription, recombination and genomic stability. Cohesin extrudes DNA into loops that are thought to lengthen until CTCF boundaries are encountered. Little is known about whether loop extrusion is impeded by DNA-bound machines. Here we show that the minichromosome maintenance (MCM) complex is a barrier that restricts loop extrusion in G1 phase. Single-nucleus Hi-C of mouse zygotes revealed that MCM loading reduces CTCF-anchored loops and decreases TAD boundary insulation, suggesting loop extrusion is impeded before reaching CTCF. This effect extends to HCT116 cells, where MCMs affect the number of CTCF-anchored loops and gene expression. Simulations suggest that MCMs are abundant, randomly positioned, partially permeable barriers. Single-molecule imaging shows that MCMs are physical barriers that frequently constrain cohesin translocation in vitro. Remarkably, chimaeric yeast MCMs harbouring a cohesin-interaction motif from human MCM3 induce cohesin pausing, suggesting that MCMs are “active” barriers with binding sites. These findings raise the possibility that cohesin can arrive by loop extrusion at MCMs, which determine the genomic sites at which sister chromatid cohesion is established. Based on in vivo, in silico and in vitro data, we conclude that distinct loop extrusion barriers shape the 3D genome.

2022-03-08 | GSE196496 | GEO

A three-dimensional map of the human genome at kilobase resolution reveals prinicples of chromatin looping

Project description:We use in situ Hi-C to probe the three-dimensional architecture of genomes, constructing haploid and diploid maps of nine cell types. The densest, in human lymphoblastoid cells, contains 4.9 billion contacts, achieving 1-kilobase resolution. We find that genomes are partitioned into local domains, which are associated with distinct patterns of histone marks and segregate into six subcompartments. We identify ~10,000 loops. These loops frequently link promoters and enhancers, correlate with gene activation, and show conservation across cell types and species. Loop anchors typically occur at domain boundaries and bind CTCF. CTCF sites at loop anchors occur predominantly (>90%) in a convergent orientation, with the asymmetric motifs ‘facing’ one another. The inactive X-chromosome splits into two massive domains and contains large loops anchored at CTCF-binding repeats. in situ Hi-C and dilution Hi-C were used to probe the three-dimensional structure of the genome in eight diverse human cell types and one mouse cell type

2014-12-11 | E-GEOD-63525 | biostudies-arrayexpress

MCM complexes are barriers that restrict loops and TADs

2022-03-07 | GSE155971 | GEO

Hi-C in mouse fetal liver cells

Project description:HindIII Hi-C dataset from mouse fetal liver cell samples to assess the performance of interaction calling algorithms.

2016-02-01 | E-MTAB-3891 | biostudies-arrayexpress

MCM complexes are barriers that restrict cohesin-mediated loop extrusion [snHi-C]

2022-03-08 | GSE196300 | GEO

The cohesin acetylation cycle controls chromatin loop length through a PDS5A brake mechanism

Project description:Cohesin structures the genome through the formation of chromatin loops and by holding together the sister chromatids. The acetylation of cohesin’s SMC3 subunit is a dynamic process that involves the acetyltransferase ESCO1 and deacetylase HDAC8. Here we show that this cohesin acetylation cycle controls the 3D genome. ESCO1 restricts the length of chromatin loops and architectural stripes, while HDAC8 promotes the extension of such loops and stripes. This role in controlling loop length turns out to be distinct from the canonical role of cohesin acetylation that protects against WAPL-mediated DNA release. We reveal that acetylation rather controls cohesin’s interaction with PDS5A to restrict chromatin loop length. Our data supports a model in which this PDS5A-bound state acts as a brake that enables the pausing and restart of loop enlargement. The cohesin acetylation cycle hereby provides punctuation in the process of genome folding.

2022-03-14 | PXD032185 | Pride

Hi-TrAC reveals fine-scale chromatin structures organized by transcription factors

Project description:The three-dimensional genomic structure plays a critical role in gene expression, cellular differentiation, and pathological conditions. Previous studies have extensively investigated the structures including A/B compartments and topologically associating domains (TADs) at a scale from hundreds of kilobases (kb) to megabases (Mb). However, fine-scale chromatin architectures, particularly enhancer-promoter interactions, which are often within 100 kb and critical for the temporospatial regulation of expression, remain to be fully characterized due to technical limitations. In this study, we report Hi-TrAC as a proximity ligation free, robust, and sensitive technique to profile genome-wide chromatin interactions at high-resolution among accessible regulatory elements. Hi-TrAC detects chromatin looping among accessible chromatin regions at single nucleosome resolution. We observed that cell-specifically expressed genes are harbored in active sub-TADs. With almost half million identified loops, we constructed a comprehensive interaction network of regulatory elements across the genome. After integrating chromatin binding profiles of transcription factors (TFs), we discovered that cohesin complex and CTCF are responsible for organizing long-range chromatin loops, which are related with domain formation, whereas ZNF143 and HCFC1 are involved in structuring short-range chromatin loops between regulatory elements, which directly regulate gene expression. Thus, here we developed a new methodology to identify a delicate and comprehensive network of cis regulatory elements, revealing the complexity and a division of labor of TFs in chromatin looping for genome organization and gene expression.

2022-10-02 | GSE180175 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data