Characterizing the structural dynamics of nucleolus during cell cycle

Nucleolus is the largest membraneless organelle in the cell. It is the site of rRNA production and ribosome assembly. Nucleolar formation and persistence are governed by the liquid-liquid phase separation paradigm which must persist and adapt through the cell cycle. Here, we used 4D live-cell imaging and histogram-based image analysis to quantify the structural dynamic of nucleolus during the cell cycle. We found that nucleolar disassembly is a multi-step process and is synchronized with the cell cycle through multiple processes. The free energy of protein localization from dense to dilute phase during the disassembly process demonstrates an instability of nucleolus at the onset of mitosis.