Guidelines for Studying Mutagenesis in Quiescent Schizosaccharomyces pombe

All living organisms can enter a non-dividing state known as quiescence, which often functions as a survival strategy. In many cases, quiescent cells retain the ability to re-enter the cell cycle when conditions become favorable. Therefore, preserving the integrity of non-dividing cells is essential not only to prevent their deterioration, but also to ensure proper population re-establishment once growth resumes. This also applies to the genome, whose stability must be maintained during both proliferation and quiescence. For several years, we have investigated this aspect of quiescence in fission yeast, which enters a G0 state in response to nitrogen starvation. We have shown that wild-type G0 cells accumulate mutations over time, with a mutational spectrum distinct from that observed during proliferation. We are now extending this work to mutants defective in various DNA repair pathways. In doing so, we developed a robust protocol ensuring highly reproducible results when assessing mutagenesis in quiescent cells. Here, we describe this protocol in detail.