Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Polymer Physics Predicts the Effects of Structural Variants on Chromatin Architecture (human)

ABSTRACT: Structural variants (SVs) can result in changes in gene expression due to abnormal chromatin folding and consecutive disease. However, the prediction of such effects remains a challenge. Here we present a polymer physics based approach (PRISMR) to model chromatin folding and to predict enhancer-promoter contacts. Using the Epha4 locus as a model, the effects of pathogenic SVs were predicted in-silico and compared to published Hi-C and capture Hi-C data generated from mouse limb buds and patient-derived fibroblasts. PRISMR deconvolutes the folding complexity of the studied locus, and identifies SV-induced alterations of 3D genome organization in the homozygous as well as the heterozygous state. Our method accurately predicts the specific sites of ectopic chromatin contacts that produce extensive rewiring of regulatory interactions, causing disease by gene misexpression. PRISMR can be used to predict interactions in silico thereby providing a tool for analyzing the disease causing potential of SVs.

ORGANISM(S): Homo sapiens

PROVIDER: GSE92290 | GEO | 2018/02/12

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Polymer Physics Predicts the Effects of Structural Variants on Chromatin Architecture (mouse)

Project description:Structural variants (SVs) can result in changes in gene expression due to abnormal chromatin folding and consecutive disease. However, the prediction of such effects remains a challenge. Here we present a polymer physics based approach (PRISMR) to model chromatin folding and to predict enhancer-promoter contacts. Using the Epha4 locus as a model, the effects of pathogenic SVs were predicted in-silico and compared to published Hi-C and capture Hi-C data generated from mouse limb buds and patient-derived fibroblasts. PRISMR deconvolutes the folding complexity of the studied locus, and identifies SV-induced alterations of 3D genome organization in the homozygous as well as the heterozygous state. Our method accurately predicts the specific sites of ectopic chromatin contacts that produce extensive rewiring of regulatory interactions, causing disease by gene misexpression. PRISMR can be used to predict interactions in silico thereby providing a tool for analyzing the disease causing potential of SVs.

2018-02-12 | GSE92291 | GEO

Chromatin structure changes upon oxidative stress or UV irradiation in the yeast Saccharomyces cerevisiae

Project description:Development of molecular approaches based on chromosome conformation capture (3C) technology such as Hi-C, combined with methods for modeling and interpreting chromatin interaction data, have revolutionized the analysis of chromosome folding. Even if the impact of chromatin structure on gene expression seems likely, little is known about the dynamics of DNA compaction and the factors involved in this process still have to be determined. Using the yeast Saccharomyces cerevisiae as a model, we used Hi-C technology to evaluate how 3D chromatin structure changes during different cellular processes such as adaptation in response to stress or DNA repair. We optimized the protocol from Belton, J.M et al (1) to produce our Hi-C libraries, one from control cells, one from cells after oxidative stress and one from cells after UV irradiation. Preliminary analysis suggests that in response to oxidative stress, chromosomes tend to make more contacts in trans and less contacts in cis compared to normal condition.

2020-12-20 | E-MTAB-5825 | biostudies-arrayexpress

Dynamic interplay between structural variation and 3D chromosome organization in pancreatic cancer

Project description:We investigate the spectrum of SVs and three-dimensional (3D) chromatin architecture in human pancreatic ductal epithelial cell carcinogenesis by using the state of art long-read single molecular real time (SMRT) and high-throughput chromosome conformation capture (Hi-C) sequencing techniques. Systematic integration of matched SMRT, in situ Hi-C, and RNA-seq datasets revealed the complicated dynamic interplay of SVs and 3D chromosome organization and their impacts on gene expression. Our studies identify and focus remodeling of chromatin folding domains associated with cross boundary SVs enabling aberrant interactions between regulatory elements. Moreover, our data also demonstrate the existence of complex genomic rearrangements associated with two key driver genes CDKN2A and SMAD4, and characterize their influence on cancer related gene expression from linear view to 3D perspective.

2022-05-01 | GSE185069 | GEO

Genome-wide detection of enhancer-hijacking events from chromatin interaction data in rearranged genomes

Project description:Recent efforts have shown that structural variations (SVs) can disrupt three-dimensional genome organization and induce enhancer hijacking, yet no computational tools exist to identify such events from chromatin interaction data. Here, we develop NeoLoopFinder, a computational framework to identify the chromatin interactions induced by SVs, including interchromosomal translocations, large deletions and inversions. Our framework can automatically resolve complex SVs, reconstruct local Hi-C maps surrounding the breakpoints, normalize copy number variation and allele effects and predict chromatin loops induced by SVs. We applied NeoLoopFinder in Hi-C data from 50 cancer cell lines and primary tumors and identified tens of recurrent genes associated with enhancer hijacking. To experimentally validate NeoLoopFinder, we deleted the hijacked enhancers in prostate adenocarcinoma cells using CRISPR–Cas9, which significantly reduced expression of the target oncogene. In summary, NeoLoopFinder enables identification of critical oncogenic regulatory elements that can potentially reveal therapeutic targets.

2021-03-23 | GSE161493 | GEO

The genome organization of Neurospora crassa at high-resolution uncovers principles of fungal chromosome topology

Project description:For a eukaryotic genome to properly function, its chromatin must be precisely organized, as genome topology impacts transcriptional regulation, cell division, DNA replication, and DNA repair, among other essential processes. Disruption of human genome topology can lead to disease states, such as cancer. The advent of chromosome conformation capture with high-throughput sequencing (Hi-C) technologies to assess genome organization has revolutionized our understanding of the arrangement of chromosomes within the nuclear genome. Critical developments include chromosomal territories, active/silent chromatin compartments, Topologically Associated Domains (TADs), and chromatin loops. However, to fully elucidate folding principles at the gene level, Hi-C datasets at an extremely high resolution are required: while low resolution (e.g., 40 kb bin) heatmaps can provide important insights into chromosomal level contacts, lower resolution datasets cannot provide information about individual gene or promoter contacts. Thus, high-resolution Hi-C datasets can elucidate principles of folding, including those of model organisms whose chromosome conformation can elucidate the folding of the human genome. Here, we have examined the high-resolution genome topology of the model fungal organism Neurospora crassa: our composite Hi-C dataset, generated using two restriction enzymes to monitor euchromatin (DpnII) and heterochromatin (MseI), provides exquisite detail for both larger chromosomal structures and individual gene contacts, including how repressed euchromatic genes associate with constitutive heterochromatic regions. Our high-resolution Neurospora Hi-C datasets should be an outstanding resource to the fungal community and provide valuable insights to the folding of higher organism genomes.

2022-03-01 | GSE173593 | GEO

A PRE loop at the dac locus acts as a topological chromatin structure that restricts and specifies enhancer promoter communication

Project description:3D genome folding plays a fundamental role for the regulation of developmental genes by facilitating or constraining chromatin interactions between cis-regulatory elements (CREs). Polycomb response elements (PREs) are a specific kind of CREs involved in the memory of transcriptional states in Drosophila melanogaster. PREs act as nucleation sites for Polycomb group (PcG) proteins, which deposit the repressive histone mark H3K27me3, leading to the formation of a class of topologically associating domain (TADs) called Polycomb domains. PREs can establish looping contacts that stabilize gene repression of key developmental genes during development. However, the mechanism by which PRE loops fine tune gene expression is unknown. Using CRISPR/Cas9 genome engineering, we specifically perturbed PRE contacts or enhancer function and used complementary approaches including 4C-seq, Hi-C, and Hi-M to analyze how chromatin architecture perturbation affects gene expression. Our results suggest that the PRE loop at the dac gene locus acts as a constitutive 3D chromatin scaffold during Drosophila development that forms independently of gene expression states and has a versatile function: it restricts enhancer promoter communication and contributes to enhancer specificity.

2024-06-13 | GSE247377 | GEO

Metaphase-Chromosome-Organization

Project description:Mitotic chromosomes are among the most recognizable structures in the cell, yet for over a century their internal organization remains largely unsolved. We applied chromosome conformation capture methods, 5C and Hi-C, across the cell cycle and revealed two alternative three-dimensional folding states of the human genome. We show that the highly compartmentalized and cell-type-specific organization described previously for non-synchronous cells is restricted to interphase. In metaphase, we identify a homogenous folding state, which is locus-independent, common to all chromosomes, and consistent among cell types, suggesting a general principle of metaphase chromosome organization. Using polymer simulations, we find that metaphase Hi-C data is inconsistent with classic hierarchical models, and is instead best described by a linearly-organized longitudinally compressed array of consecutive chromatin loops.

2013-11-05 | E-MTAB-1948 | biostudies-arrayexpress

Promoter capture Hi-C of human SGBS (Simpson-Golabi-Behmel syndrome preadipocyte) cells and iPSC-derived hypothalamic cells

Project description:To identify distal chromatin contacts between promoters and their putative regulatory elements in SGBS preadipocytes and hypothalamic arcuate-like neurons derived from iPSC, we performed Hi-C with a capture step to enrich the library for contacts involving promoters. Hi-C with a capture step was performed according to PMID: 29988018

2021-03-20 | E-MTAB-10200 | biostudies-arrayexpress

Active chromatin and transcription play a key role in chromosome partitioning into topologiÑ?ally associating domains

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

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

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