Abstract:
Cytologically visible constitutive heterochromatin found at the
centromeric and telomeric regions of chromosomes represents
the largest differentiated chromatin compartment in eukaryotic
nuclei.1 Outside constitutive heterochromatin, heterochromatin-
like domains (HLD, >.1 Mb) and complexes
(HLC, <.1 Mb) are found along the chromosome arms.2
HLD/Cs are present in eukaryotic genomes as divergent as fission
yeast and human, with expansions in size and number in
mammals. In human, there are ~163 to 859 HLDs and ~18 853
to 32 292 HLCs, depending on cell type.2 Some of the largest
HLDs are the KRAB-ZNF HLDs on chromosome 19.
Notably, contacts among these large HLDs emerge as the heterochromatic
B4 sub-compartment in Hi-C maps...