A systematic genetic screen identifies essential factors involved in nuclear size control

Nuclear size correlates with cell size, but the mechanism by which this scaling is achieved is not known. Here we screen fission yeast gene deletion mutants to identify essential factors involved in this process. Our screen has identified 25 essential factors that alter nuclear size, and our analysis has implicated RNA processing and LINC complexes in nuclear size control. This study has revealed lower and more extreme higher nuclear size phenotypes and has identified global cellular processes and specific structural nuclear components important for nuclear size control.

Author summary As cells grow and divide, the size of the nucleus is generally maintained as a fixed proportion of cell size. The mechanism by which this nuclear/cytoplasmic ratio is maintained is unclear. Previous studies have suggested that essential gene products may be important for nuclear size control. Therefore, we have exploited the genetic tractability of fission yeast to carry out a systematic genetic screen of deleted essential genes to identify those with aberrant nuclear size phenotypes. Our study has revealed 25 novel genes that influence nuclear size and our bioinformatic analyses have implicated both RNA processing and protein complexes connecting nuclear chromatin to the cytoskeleton in nuclear size control. Our work sheds light on the biological processes that contribute to nuclear size control in fission yeast contributing to our mechanistic understanding of nuclear scaling, a biological phenomenon that is conserved through evolution.