A Starvation-Induced Heritable Stress-Resistant State in Saccharomyces cerevisiae

Transient exposures to diverse stimuli induce altered physiological properties in exposed cells that persist after the stimulus has been removed. This state, referred to as cellular memory, can be passed on to daughter cells. In the budding yeast Saccharomyces cerevisiae, I found that meiotically produced yeast spores possess a state of heightened stress resistance that, following their germination, is propagated through their descendants. As yeast meiotic development is essentially a starvation response that diploid cells engage, I modelled this phenomenon by subjecting haploid cells to starvation conditions. Haploid cells exposed to glucose withdrawal acquire elevated hydrogen peroxide resistance following the reintroduction of the cells to glucose-replete-media. In both haploid starved cells and diploid produced meiotic spores I show that their cellular memories are not attributable to trehalose, a proposed stress protectant. My findings identify nutritionally induced states of cellular memory in yeast that exhibit striking degrees of persistence and inheritance.M.Sc