Age distribution formulas for budding yeast

Abstract

Yeast are an important eukaryotic model system in the study of aging. Replicative age in budding yeast can be quantitatively determined by visualizing chitanous bud scars. The dynamics of the process of growth and division effects the distribution of replicative age. How much physiological information is encoded in experimental age distributions is not fully understood. Formulas relating the stationary age distribution to the spectrum of generational and culture doubling times have been proposed by several authors over the past four decades. We discuss the assumptions upon which they rest and some natural extensions. We describe the replicative age distribution of a population growing exponentially in terms of generational flux residence times. We demonstrate the utility of this description and show that it produces excellent agreement with experimental data, and describe how it compares with previous work. We demonstrate that the age distribution in a variety of strains can be predicted by a realistic population model, and we indicate how the age distribution is altered by perturbations and control.