Project description:Whole genome bisulfite sequencing of wild type embryonic stem cells and cells bearing a mutation that perturbs the OGT-TET1 interaction Overall design: Whole genome bisulfite sequencing in wild type and Tet1 D2018A mutant mESCs
Project description:Background: Recent genome-wide association studies (GWAS) have identified more than 100 loci associated with increased risk of prostate cancer, most of which are in non-coding regions of the genome. Understanding the function of these non-coding risk loci is critical to elucidate the genetic susceptibility to prostate cancer. Results: We generated genome-wide regulatory element maps and performed genome-wide chromosome confirmation capture assays (in situ Hi-C) in normal and tumorigenic prostate cells. Using this information, we annotated the regulatory potential of 2,181 fine-mapped PCa risk-associated SNPs and predicted a set of target genes that are regulated by PCa risk-related H3K27Ac-mediated loops. We next identified PCa risk-associated CTCF sites involved in long-range chromatin loops. We used CRISPR-mediated deletion to remove PCa risk-associated CTCF anchor regions and the CTCF anchor regions looped to the PCa risk-associated CTCF sites; we observed up to 100 fold increases in expression of genes within the loops when the PCa risk-associated CTCF anchor regions were deleted. Conclusions: We have identified GWAS risk loci involved in long-range loops that function to repress gene expression within chromatin loops. Our studies provide new insights into the genetic susceptibility to prostate cancer. Overall design: ChIP-seq, RNA-seq, Hi-C in prostate cells.
Project description:Genome organization involves cis and trans chromosomal interactions, both implicated in gene regulation, development, and disease. Here, we focused on trans interactions in Drosophila, where homologous chromosomes are paired in somatic cells from embryogenesis through adulthood. We first addressed the long-standing question of whether pairing extends genome-wide and, to this end, developed a haplotype-resolved Hi-C approach that uses a new strategy to minimize homolog misassignment and thus robustly distinguish trans-homolog from cis contacts. This approach revealed striking genome-wide pairing in Drosophila embryos. Moreover, we discovered pairing to be surprisingly structured, with trans-homolog domains and interaction peaks, many coinciding with the positions of analogous cis features. We also found a significant correlation between pairing and the chromatin accessibility mediated by the pioneer factor Zelda. Our findings reveal a complex, highly structured organization underlying homolog pairing, first discovered more than a century ago. Overall design: This submission contains data from a Hi-C experiment on Early Drosophila embryos (2 biological replicates).
Project description:Trans-homolog interactions encompass potent regulatory functions, which have been studied extensively in Drosophila, where homologs are paired in somatic cells and pairing-dependent gene regulation, or transvection, is well-documented. Nevertheless, the structure of pairing and whether its functional impact is genome-wide have eluded analysis. Accordingly, we generated a diploid cell line from divergent parents and applied haplotype-resolved Hi-C, discovering that homologs pair relatively precisely genome-wide in addition to establishing trans-homolog domains and compartments. We also elucidated the structure of pairing with unprecedented detail, documenting significant variation across the genome. In particular, we characterized two forms: tight pairing, consisting of contiguous small domains, and loose pairing, consisting of single larger domains. Strikingly, active genomic regions (A-type compartments, active chromatin, expressed genes) correlated with tight pairing, suggesting that pairing has a functional role genome-wide. Finally, using RNAi and haplotype-resolved Hi-C, we show that disruption of pairing-promoting factors results in global changes in pairing. Overall design: This submission contains four Hi-C experiments on a Drosophila cell line: 2 biological replicates of Hi-C on a wild type sample, 2 biological replicates of Hi-C on a mock RNAi sample, 2 biological replicates of Hi-C on a Slmb RNAi sample, 2 biological replicates of Hi-C on a Top2 RNAi sample. The submission also contain 4 biological replica of a RNA-Seq experiment on a Wild Type sample.
Project description:MeCP2 plays a multifaceted role in gene expression regulation and chromatin organization. Interaction between MeCP2 and methylated DNA to regulate gene expression is well established. However, the widespread MeCP2 distribution suggests its additional interactions with chromatin. Here we show, by both biochemical and ChIP-seq analyses, that MeCP2 directly binds to nucleosome subunit proteins and is recruited to distinct chromatin regions where H3K27me3 is enriched. We further observed that the impact of MeCP2 on transcriptional changes is correlated with histone post-translational modification patterns. Our findings indicate that MeCP2 can be recruited to genomic loci via indirect binding and that interaction between MeCP2 and histone proteins plays a significant role in gene expression regulation. Overall design: In order to perform genome-wide quantitative comparisons of histone modification difference between DMSO and GSK343 treatment, the drosophila S2 genome was added to each experiment. An exogenous genome-derived normalizing factor was used for normalization. Please note that each processed data file was generated from both rep1 and rep2 samples, and is linked to the corresponding rep1 sample records.