The eukaryotic chromatin architecture was previously divided into two types, either with (called Rabl-like, RBL) or without (called chromosome territories, CT) pronounced centromere or/and telomere clustering, possibly attributed to the absence/presence of certain subunits of condensin II. By studying time series of embryonic chromatin interaction data, we show that RBL or CT is not a species-dependent feature, instead three distantly related animals all exhibit both types of architecture, and a RBL-to-CT transition during development. This transition appears to be not related to the expression of condensin II gene, but might be influenced by the repeat distribution along chromosomes. Finally, we found a progressively establishment of long-range cis- and trans-interactions between A1 sub-compartments, leading to the dominance of CT over RBL in late developmental/adult stages.

Chromosome architecture; Rabl; CT; Hi-C; embryonic development