Intranuclear phase separation, and its role in transcription and gene regulation

Microscopy studies suggest that chromatin and its associated proteins often form phase separated droplets within the nucleus of eukaryotic organisms. I will discuss some possible biophysical mechanisms, suggested by coarse-grained molecular dynamics simulations and theory, underlying such intranuclear phase separation and microphase separation (arrested phase separation resulting in the formation of droplets of self-limiting size). I will also discuss potential functional roles of phase separation in transcription and gene regulation. We will see that these phenomena provide a way to quantitatively understand the elusive link between the 3D structure of a gene and its expression level,  and to predict the transcriptional activity of, in principle, any human gene.