Spatial organization of chromosomes leads to heterogeneous chromatin motion and drives the liquid- or gel-like dynamical behavior of chromatin

Dynamic properties of simulated chromosomes. (A) Time-averaged MSD_i,c of single trajectories of length 30 sec sampled every 0.3 sec for null (upper), mouse (middle), and Drosophila (bottom) models. (B) Distribution of the diffusion exponents α_i,c extracted from the time-averaged MSD curves given in A. (C) Distribution of the diffusion constants D_i,c for the time-averaged MSDs in A having an exponent α_i,c ≈ 0.5. Distributions for other α_i,c values are given in Supplemental Figure S3. In B and C, average values of the distributions are shown on the horizontal x-axis. (D–F) Ensemble-averaged (over all trajectories) MSD_i of all genomic loci for null (D), mouse (E), and Drosophila (F) models. To discard trivial positional effects, we exclude the last 50 monomers at the two ends of the polymers. Individual ensemble-averaged MSDs were colored from cyan (first monomer) to magenta (last monomer). (G–I) The distributions of the diffusion constant D_i (G) and of the diffusion exponent α_i (Δt) for short (Δt = 3 sec) (H), and large (Δt = 1000 sec) (I) time scales, extracted from ensemble-averaged MSD curves in panels D through F. The average values of the distributions are shown on the horizontal axes.