18 - Longevity and Aging in Budding Yeast

Abstract

This chapter presents an overview of the current understanding of how yeast ages, and the genes and pathways that play a role in determining yeast chronological and replicative life span. The replicative life span of a yeast cell is determined by the number of daughter cells produced. Like other eukaryotic species, yeast replicative mortality follows Gompertz-Makeham kinetics, consistent with the hypothesis that similar processes underlie aging in yeast and aging in higher eukaryotes. Calorie restriction (CR) is the only intervention demonstrated to increase life span in yeast, worms, flies, and mammals. CR can be accomplished in yeast by reducing the glucose concentration of the growth media, or by a number of genetic models of CR. The chronological life span of a yeast cell is defined as the length of time that a cell can maintain viability in a nondividing state. The chronological life span of a yeast cell begins under conditions highly favorable for growth: low cell density, optimal temperature, high nutrient availability, and the presence of a preferred carbon source.