Physical Models of Chromosomal Domains

How can proteins that are much smaller than chromosomes drive chromosome compaction and control functional enhancer-promoter interactions at much large scales? Recently developed Chromosome Conformation Capture technique (Hi-C) provides comprehensive information about frequencies of spatial interactions between genomic loci. We develop a top-down approach to biophysical modeling of chromosomes: Starting with a minimal set of biologically motivated interactions we build polymer models of chromosome organization that can reproduce major features observed in Hi-C experiments. Our works suggests that active processes of loop extrusion can be a universal mechanism responsible for formation of domains in interphase and chromosome compaction in metaphase.