Active Dynamics of Chromosome Polymers

Mechanical manipulation of chromosomes, driven via the forces applied by microscopic motor proteins, is an active process essential for biological function. The enormous length of the chromatin polymer makes coarse-graining an important aspect in modeling chromosomes. Effective-equilibrium descriptions of coarse-grained chromosomes have been useful in understanding structural features, however, these models are limited by their equilibrium-like dynamics and a lack of connection to microscopic activity. Here, we propose an active polymer model for chromosomes, where microscopic activity leads to non-equilibrium fluctuations at the coarse-grained length scales. Our model predicts various experimentally realizable signatures, such as the scaling of mean-squared displacement with time for various levels of activity. In all, we construct an active chromosome model and utilize it to directly probe the consequences of microscopic activity on structure and dynamics.