INVESTIGATING THE ROLE OF STRESS PATHWAY ACTIVATION IN MEIOTIC DIFFERENTIATION AND REJUVENATION IN BUDDING YEAST

Abstract

Abstract Sexually reproducing organisms undergo meiosis to produce gametes for the next generation. In budding yeast, meiosis resets replicative lifespan as gametes produced by aged progenitors are born young and devoid of any senescence-associated factors. In addition, certain transcription factors that are involved in stress response are expressed when yeast cells undergo meiosis. The overarching goal of this project is to determine the role of stress transcription factors in meiotic rejuvenation. As part of this goal, I set out to develop an assay to measure the fitness of yeast gametes that were depleted of a given stress response transcription factor. I focused on Yap1 and Skn7, two transcription factors involved in oxidative stress, and characterized gamete fitness by measuring survival in response to environmental stressors, including acid and alkaline. I found that gametes depleted for Yap1 have mild sensitivity to acid and dramatic sensitivity to alkaline. These findings implicate a role of Yap1 in gamete fitness in a physiologically relevant context since acidic and alkaline environments exist in the digestive tract of fruit flies, which are natural predators of yeast. Further investigation of how stress response transcription factors affect meiotic rejuvenation can help us develop strategies to counteract cellular aging in different contexts.