Fig. 3: Active nuclear condensates exhibit unusual steady-state morphologies.

a In the left panel, the blue plots correspond to the protein concentration profiles and the gray-black plots represent interfaces between two phases for two different values of k_T. The right panel shows the concentration profiles of the protein and the RNA as a function of the radial coordinate (r) from the center of the actively transcribing site. In the top panels (k_T = 1.0), we have a single dense phase of protein separated from the dilute phase by a single interface. In the bottom panel, increasing the gene activity to k_T = 20.0 leads to a ring-like dense phase of protein sandwiched between a dilute phase inside and outside, each separated by respective interface. We call the dilute phase inside the ring as the vacuole. In this way, increasing gene activity (k_T) can lead to a change in condensate morphology from a single droplet (top panel) to a vacuole (bottom panel). b Radius of the vacuole plotted against different magnitudes of gene activity k_T (with σ = 4 fixed) and extents of compartmentalization σ (with k_T = 90.0 fixed). c Protein concentration profiles (blue) as time progresses for two different initial conditions where k_T is large. Both simulations are done for the same values of k_T and σ. We observe that a symmetric vacuole is initially formed. This symmetry is broken as time progresses and we end up with an aspherical droplet at steady state. Please refer Supplementary Table 3 for details of simulation parameters.