Biophysical mechanisms of chromatin patterning.

Cells compartmentalize their genome into active and inactive parts that contain distinct histone marks and are differently packaged. Recent work has shed new light on the mechanisms that drive this type of chromatin patterning and the properties of the resulting domains. Biophysical concepts such as liquid-liquid phase separation, polymer looping and collapse, molecular crowding and viscoelasticity are increasingly used to describe experimental observations. Accordingly, it is becoming clear that the physicochemical properties of the nuclear interior are relevant for understanding chromatin compartmentalization. Here, I discuss recent insights into the properties of chromatin subcompartments obtained with complementary techniques on different scales, and relate them to models for functional chromatin patterning.