Using eHi-C to map chromatin loops in mouse beta cells
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA749602 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:eHiC data of mouse beta cells from C57BL/6 mice
2021-07-27 | GSE180809 | GEO
Project description:Studying the conservation and differences of regulation between human and mouse helps understand gene regulation on mouse models. Chromatin loop is an important gene regulatory mechanism to drive the 3D regulation between genes and their regulatory elements. Here, we performed eHi-C to profile genome wide contacts in mouse strains B6 and CAST islet beta cells, together with the loops identified in human islet alpha and beta cells from previous studies (GSE195523). The results show that the conserved chromation loop and open chromatin regions highlight the function of T2D risk loci and improve our understanding in islet biology.
2024-01-31 | GSE196729 | GEO
Project description:R-loops are features of chromatin consisting of a strand of DNA hybridized to RNA, as well as the expelled complementary DNA strand. R-loops are enriched at promoters where they have recently been shown to have important roles in modifying gene expression. However, the location of promoter-associated R-loops and the genomic domains they perturb to modify gene expression remain unclear. To resolve this issue, we developed a bisulfite-based approach, bisDRIP-seq, to map R-loops across the genome at near-nucleotide resolution in MCF-7 cells. We found the location of promoter-associated R-loops is dependent on the presence of introns. In intron-containing genes, R-loops are bounded between the transcription start site and the first exon-intron junction. In intronless genes, the 3' boundary displays gene-specific heterogeneity. Moreover, intronless genes are often associated with promoter-associated R-loop formation. Together, these studies provide a high-resolution map of R-loops and identify gene structure as a critical determinant of R-loop formation.
2017-10-25 | GSE98886 | GEO
Project description:The formation of R-loops is a natural consequence of the transcription process, caused by invasion of the DNA duplex by nascent transcripts. These structures have been considered rare transcriptional by-products with potential harmful effects on genome integrity, due to the fragility of the displaced DNA coding strand. However R-loops may also possess beneficial effects as their widespread formation has been detected over CpG island promoters in human genes. Furthermore we have previously shown that R-loops are particularly enriched over G-rich terminator elements. These facilitate RNA polymerase II (Pol II) pausing prior to efficient termination. Here we reveal an unanticipated link between R-loops and RNA interference (RNAi)-dependent H3K9me2 formation over pause site termination regions of mammalian protein coding genes. We show that R-loops induce antisense transcription over these pause elements which in turn lead to the generation of double-strand RNA (dsRNA) and recruitment of Dicer, Ago1, Ago2, and G9a histone lysine methyltransferase (HKMT). Consequently an H3K9me2 repressive mark is formed and Heterochromatin Protein 1γ (HP1γ) is recruited, that reinforces Pol II pausing prior to efficient transcriptional termination. We predict that R-loops promote a chromatin architecture that defines the termination region for a substantial subset of mammalian genes. PolIIS2ph ChIP-seq and input in untreated condition and treated with BIX and RNaseH1 overexpression in HeLa cells. The 4 samples have been multiplexed, pooled and sequenced on 3 lanes of Illumina HiSeq2000.
2014-09-29 | E-GEOD-59878 | biostudies-arrayexpress
Project description:R-loops are transcription by-products that may constitute a threat to genome integrity. In addition to specific enzymes to remove them, eukaryotes rely on a number of mRNP biogenesis factors such as the THO complex, to prevent co-transcriptional R-loop formation. We show in Saccharomyces cerevisiae that R-loops are tightly and specifically linked with histone H3-Ser10 phosphorylation (H3S10P), a mark of chromatin condensation. Importantly, ChIP-chip analyses reveal a clear H3S10P accumulation at the pericentromeric chromatin during the G1-phase of the cell cycle only in R loop-accumulating yeast strains but not in those non-accumulating R-loops, and a significantly higher accumulation during S-phase. Such a difference can also be detected in a number of genes along the genome. ChIP-chip studies were perfomed with antibodies against Histone H3 and the phosphorylated Histone H3 at Serine10 in the yeast S. cerevisiae.
2013-11-13 | E-GEOD-46627 | biostudies-arrayexpress
Project description:A high-resolution 3D epigenomic map reveals insights into the creation of the prostate cancer transcriptome Prostate cancer (PCa) is the leading cancer among men in the United States. To understand gene regulation in 3D, chromatin interactions in prostate cancer cell is measured using in situ Hi-C. To better understand the impact of chromatin structure on regulation of the prostate cancer transcriptome, we developed high-resolution chromatin interaction maps in normal and prostate cancer cells using in situ Hi-C. By combining the in situ Hi-C data with active and repressive histone marks, CTCF binding sites, nucleosome-depleted regions, and transcriptome profiling, we identified topologically associating domains that changed in size and epigenetic states between normal and prostate cancer cells. Moreover, we identified normal and prostate cancer-specific enhancer-promoter loops and involved transcription factors. This creation of 3D epigenomic maps will enable a better understanding of prostate cancer biology and mechanisms of gene regulation.
2019-09-13 | GSE118629 | GEO
Project description:A prostate cancer chromatin interaction map
| PRJNA486278 | ENA
Project description:The locations of chromatin loops in Drosophila were determined by Hi-C (chemical cross-linking, restriction digestion, ligation, and high-throughput DNA sequencing). Whereas most loop boundaries or "anchors" are associated with CTCF protein in mammals, loop anchors in Drosophila were found most often in association with the polycomb group (PcG) protein Polycomb (Pc), a subunit of polycomb repressive complex 1 (PRC1). Loops were frequently located within domains of PcG-repressed chromatin. Promoters located at PRC1 loop anchors regulate some of the most important developmental genes and are less likely to be expressed than those not at PRC1 loop anchors. Although DNA looping has most commonly been associated with enhancer-promoter communication, our results indicate that loops are also associated with gene repression.
| S-EPMC5565414 | biostudies-literature
Project description:In most plants, centromeric DNA contains highly repetitive sequences, including tandem repeats and retrotransposons; however, the roles of these sequences in the structure and function of the centromere are unclear. Here, we found that retrotransposon-derived back-spliced RNA can bind to the centromere through R-loops and regulate the formation of centromeric chromatin loops. Multiple RNA sequences from centromeric retrotransposons (CRMs) were enriched in maize (Zea mays) centromeres and back spliced RNA from CRM1 were detected. We identified three types of circular CRM1 RNAs with the same back-splicing site based on the back-spliced sequences. These circular RNAs bound to the centromere through R-loops. Two R-loop sites inside a single circular RNA promoted the formation of chromatin loops in CRM1 regions. When RNAi was used to target the back-spliced site of the circular CRM1 RNAs, the levels of R-loops and chromatin loops formed by these circular RNAs decreased, while the levels of R-loops produced by linear RNAs with similar binding sites increased. Linear RNAs with only one R-loop site could not promote chromatin loop formation. Higher levels of R-loops and lower levels of chromatin loops in the CRM1 regions of RNAi plants led to a reduced localization of the centromeric H3 variant (CENH3). Our work reveals that centromeric chromatin organization by circular CRM1 RNAs via R-loops and chromatin loops. R-loops are integral components of centromeric chromatin. Proper centromere structure is essential for CENH3 localization. CRM1 elements may have helped to build a suitable chromatin environment during centromere evolution.
2020-01-01 | GSE137701 | GEO
Project description:Genome-wide chromatin interactions identify characteristic promoter-distal loops
| PRJNA528483 | ENA