Project description:We developed a targeted chromosome conformation capture (4C) approach that uses unique molecular identifiers (UMI) to derive high complexity quantitative chromosome contact profiles with controlled signal to noise ratios. We demonstrate that the method improves the sensitivity and specificity for detection of long-range chromosomal interactions, and that it allows the design of interaction screens with predictable statistical power. UMI-4C robustly quantifies contact intensity changes between cell types and conditions, opening the way toward incorporation of long-range interactions in quantitative models of gene regulation. We constructed UMI-4C profiles of 13 different genomic loci (viewpoints) in five different cell lines, in order to study the 3D chromatin contact maps of these selected loci. The coordinates for these viewpoints are: G1p1 chrX:48646542; baitG1_3_5kb chrX:48641393; bait_50kb chrX:48595987; bait_165kb chrX:48476525; ANK1 chr8:41654693; hbb_3HS chr11:5221346; hbb_HBB chr11:5248714; hbb_HBBP1_G1 chr11:5266532; HBB_HBE chr11:5292159; HBB_HS2 chr11:5301345; HBB_HS3 chr11:5306690; HBB_HS5 chr11:5313539; HBB_HBD chr11:5256597
Project description:We developed a targeted chromosome conformation capture (4C) approach that uses unique molecular identifiers (UMI) to derive high complexity quantitative chromosome contact profiles with controlled signal to noise ratios. We demonstrate that the method improves the sensitivity and specificity for detection of long-range chromosomal interactions, and that it allows the design of interaction screens with predictable statistical power. UMI-4C robustly quantifies contact intensity changes between cell types and conditions, opening the way toward incorporation of long-range interactions in quantitative models of gene regulation.
Project description:We developed a targeted chromosome conformation capture (4C) approach that uses unique molecular identifiers (UMI) to derive high complexity quantitative chromosome contact profiles with controlled signal to noise ratios. We demonstrate that the method improves the sensitivity and specificity for detection of long-range chromosomal interactions, and that it allows the design of interaction screens with predictable statistical power. UMI-4C robustly quantifies contact intensity changes between cell types and conditions, opening the way toward incorporation of long-range interactions in quantitative models of gene regulation.
Project description:We describe that during early zebrafish development, DNA methylation has little influence on enhancer activity, and that hypo-methylation is a unique feature of primed enhancers, whereas active enhancers are generally hyper-methylated. Hypo-methylated enhancers (hypo-enhancers) are enriched close to important transcription factors (TFs) that act later in development, are specifically de-methylated before the mid blastula transition (MBT), and reside in a unique epigenetic environment. Finally, we demonstrate that hypo-enhancers are functionally active later in development and that they are physically associated with the transcriptional start site (TSS) of target-genes, irrespective of target-gene activity. We performed 6 different 4C-Seq experiment at two different timepoints and in adult brain.
Project description:CCCTC-binding factor (CTCF) is an architectural protein involved in the three-dimensional organization of chromatin. In this study, we systematically assayed the 3D genomic contact profiles of hundreds of CTCF binding sites in multiple tissues with high-resolution 4C-seq. We find both developmentally stable and dynamic chromatin loops. As recently reported, our data also suggest that chromatin loops preferentially form between CTCF binding sites oriented in a convergent manner. To directly test this, we used CRISPR-Cas9 genome editing to delete core CTCF binding sites in three loci, including the CTCF site in the Sox2 super-enhancer. In all instances, CTCF and cohesin recruitment were lost, and chromatin loops with distal CTCF sites were disrupted or destabilized. Re-insertion of oppositely oriented CTCF recognition sequences restored CTCF and cohesin recruitment, but did not re-establish chromatin loops. We conclude that CTCF binding polarity plays a functional role in the formation of higher order chromatin structure. 4C-seq was performed on a large number of viewpoints in E14 embryonic stem cells, neural precursor cells and primary fetal liver cells
Project description:For ease of visual inspection of 4C data we present 4See, a versatile and user-friendly browser. 4See allows 4C profiles from the same bait to be flexibly plotted together, allowing biological replicates to either be compared, or pooled for comparisons between different cell types or experimental conditions. 4C profiles can be integrated with gene tracks, linear epigenomic profiles and annotated regions of interest, such as called significant interactions, allowing rapid data exploration with limited computational resources or bioinformatics expertise.
Project description:In this study, we performed 4C sequencing experiments to investigate the change of chromatin interactions between the promoters of Pcdh genes and enhancers across cPcdh locus.