High Resolution Maps of the HeLa 3D Genome Using Hi-C

We use in situ Hi-C to probe the three-dimensional architecture of genomes, constructing haploid and diploid maps of nine cell types (including HeLa). The densest, in human lymphoblastoid cells, contains 4.9 billion contacts, achieving 1-kilobase resolution. We find that genomes are partitioned into contact domains (median length, 185kb), which are associated with distinct patterns of histone marks and segregate into six subcompartments. We identify ~10,000 loops. These loops frequently link promoters and enhancers, correlate with gene activation, and show conservation across cell types and species. Loop anchors typically occur at domain boundaries and bind CTCF. CTCF sites at loop anchors occur predominantly (>90%) in a convergent orientation, with the asymmetric motifs 'facing' one another. The inactive X-chromosome splits into two massive domains and contains large loops anchored at CTCF-binding repeats. The data for the other (non-HeLa) cell types has been uploaded to GEO.]]>