Activity-Driven Phase Transition Causes Coherent Flows of Chromatin

We discover a new type of nonequilibrium phase transition in model chromatin dynamics, which accounts for the coherent motions that have been observed experiment. The motion is due to long-range cooperation molecular motors tethered chromatin. Cooperation occurs if each motor acts simultaneously on polymer and surrounding solvent, exerting them equal opposite forces. This drives flow solvent past polymer, turn affects orientation nearby and, drive strong enough, an active polar (``ferromagnetic'') can spontaneously form. Depending boundary conditions, either transverse flows, or sustained longitudinal oscillations waves are possible. Predicted time length scales consistent with experiments. now hand coarse-grained description dynamics reproduces directed flows seen field-theoretic be analytically coupled other features nuclear environment such as fluctuating porous boundaries, local heterogeneities distribution its activity, leading insights effects activity cell nucleus contents.