DNA of the human genome is 2m long and is folded into chromosomes that fit in 10-micron cellular nucleus. How are these long polymers of DNA folded and organized in 3D inside the nucleus? How can proteins that are much smaller than chromosomes drive chromosome compaction, segregation or control functional interactions at much larger scales?
Recently developed experimental technique (Hi-C) provides comprehensive information about frequencies of spatial interactions between genomic loci. Inferring principles of 3D organization of chromosomes from these data is a challenging biophysical problem, rooted in statistical physics of polymers. Our recent works suggest that chromosomes are organized by an active, energy-consuming, process. We demonstrate that a single active process of “loop extrusion” be a universal mechanism responsible for formation of domains in interphase, and chromosome compaction and segregation in metaphase. I will provide recent experimental evidence of to support of our proposed mechanism.