CHiCAGO: Robust Detection of DNA Looping Interactions in Capture Hi-C data
Ontology highlight
ABSTRACT: Capture Hi-C (CHi-C) is a state-of-the art method for profiling chromosomal interactions involving targeted regions of interest (such as gene promoters) globally and at high resolution. Signal detection in CHi-C data involves a number of statistical challenges that are not observed when using other Hi-C-like techniques. We present a background model, and algorithms for normalisation and multiple testing that are specifically adapted to CHi-C experiments, in which many spatially dispersed regions are captured, such as in Promoter CHi-C. We implement these procedures in CHiCAGO (http://regulatorygenomicsgroup.org/chicago), an open-source package for robust interaction detection in CHi-C. We validate CHiCAGO by showing that promoter-interacting regions detected with this method are enriched for regulatory features and disease-associated SNPs.
Project description:Capture Hi-C (CHi-C) is a state-of-the art method for profiling chromosomal interactions involving targeted regions of interest (such as gene promoters) globally and at high resolution. Signal detection in CHi-C data involves a number of statistical challenges that are not observed when using other Hi-C-like techniques. We present a background model, and algorithms for normalisation and multiple testing that are specifically adapted to CHi-C experiments, in which many spatially dispersed regions are captured, such as in Promoter CHi-C. We implement these procedures in CHiCAGO (http://regulatorygenomicsgroup.org/chicago), an open-source package for robust interaction detection in CHi-C. We validate CHiCAGO by showing that promoter-interacting regions detected with this method are enriched for regulatory features and disease-associated SNPs. Three human CHi-C biological replicates were generated (comprising 1, 2and 3 technical replicates). Two mouse CHi-C biological replicates were generated (both comprising three technical replicates) and a mouse Hi-C dataset. The publicly available HiCUP pipeline (doi: 10.12688/f1000research.7334.1) was used to process the raw sequencing reads. This pipeline was used to map the read pairs against the mouse (mm9) and human (hg19) genomes, to filter experimental artefacts (such as circularized reads and re-ligations), and to remove duplicate reads. For the CHi-C data, the resulting BAM files were processed into CHiCAGO input files, retaining only those read pairs that mapped, at least on one end, to a captured bait. CHiCAGO then identified Hi-C restriction fragments interacting, with statistical significant, to captured baits.
Project description:Capture Hi-C (CHi-C) is a new technique for assessing genome organization based on chromosome conformation capture coupled to oligonucleotide capture of regions of interest, such as gene promoters. Chromatin loop detection is challenging because existing Hi-C/4C-like tools, which make different assumptions about the technical biases presented, are often unsuitable. We describe a new approach, ChiCMaxima, which uses local maxima combined with limited filtering to detect DNA looping interactions, integrating information from biological replicates. ChiCMaxima shows more stringency and robustness compared to previously developed tools. The tool includes a GUI browser for flexible visualization of CHi-C profiles alongside epigenomic tracks. The results of the analysis on existing mouse ES Capture Hi-C data (ArrayExpress E-MTAB-2414) were validated by two 4C-seq experiments, submitted here.
Project description:Hi-C and promoter capture Hi-C data for HT29 and LoVo.
2 replicates per cell line for the Hi-C.
3 replicates per cell line for the CHi-C.
Project description:Genome organization influences transcriptional regulation by facilitating interactions between gene promoters and distal regulatory elements. To analyse distal promoter contacts we used Capture Hi-C (CHi-C) to enrich for promoter-interactions in a HiC lib
Project description:Genome-wide chromosome conformation capture (Hi-C) and promoter-capture Hi-C (CHi-C) were performed during epidermal differentiation. These data indicate that dynamic and constitutive enhancer-promoter contacts combine to control gene induction during differentiation and that chromosome conformation enables discovery of new TFs with distinct roles in this process.
Project description:Genome-wide chromosome conformation capture (Hi-C) and promoter-capture Hi-C (CHi-C) were performed during epidermal differentiation. These data indicate that dynamic and constitutive enhancer-promoter contacts combine to control gene induction during differentiation and that chromosome conformation enables discovery of new TFs with distinct roles in this process.
Project description:Genome-wide chromosome conformation capture (Hi-C) and promoter-capture Hi-C (CHi-C) were performed during epidermal differentiation. These data indicate that dynamic and constitutive enhancer-promoter contacts combine to control gene induction during differentiation and that chromosome conformation enables discovery of new TFs with distinct roles in this process.
Project description:Genome-wide chromosome conformation capture (Hi-C) and promoter-capture Hi-C (CHi-C) were performed during epidermal differentiation. These data indicate that dynamic and constitutive enhancer-promoter contacts combine to control gene induction during differentiation and that chromosome conformation enables discovery of new TFs with distinct roles in this process.
Project description:We propose a novel in situ Hi-C method named Bridge-Linker-Hi-C (BL-Hi-C) for structural and regulatory chromatin interactions capture by restriction enzyme targeting and two-step proximity ligation. It improves the sensitivity and specificity for active chromatin loop detection and can reveal a better enhancer-promoter regulatory architecture than conventional method at a lower sequencing depth and with a simpler protocol.