ABSTRACT The question of why and how some species or individuals within a population live longer than others is among the most important questions in the biology of aging. A particularly useful model to understand the genetic basis and selective forces acting on the plasticity of lifespan are closely related species or ecologically diverse individuals of the same species widely different in lifespan. Here, we analyzed 76 diverse wild isolates of two closely related budding yeast species Saccharomyces cerevisiae and Saccharomyces paradoxus and discovered a diversity of natural intra-species lifespan variation. We sequenced the genomes of these organisms and analyzed how their replicative lifespan is shaped by nutrients and transcriptional and metabolite patterns. We identified sets of genes and metabolites to regulate aging pathways, many of which have not been previously associated with lifespan regulation. We also identified and characterized long-lived strains with elevated intermediary metabolites and differentially regulated genes for NAD metabolism and the control of epigenetic landscape through chromatin silencing. Our data further offer insights into the evolution and mechanisms by which caloric restriction regulates lifespan by modulating the availability of nutrients without decreasing fitness. Overall, our study shows how the environment and natural selection interact to shape diversity of lifespan.

Evolution of Natural Lifespan Variation and Molecular Strategies of Extended Lifespan