Genetic and Ecotypic Structure of Natural Saccharomyces Populations

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

This project will study the structure and ecological variability of naturally occurring populations of the brewer's and baker's yeast Saccharomyces cerevisiae and its sister species Saccharomyces paradoxus. In preliminary work, the principle investigator (PI) has shown that both of these yeast species are widespread in natural woodland environments, where they are found in association with oaks. The PI's laboratory has established a large collection of both species from such habitats in the midwestern and mid-Atlantic United States. In the current project, further collections of both species will be carried out at vineyard sites in the same regions. DNA sequence data and standard microbiological methods will then be used to characterize geographic patterns of genetic variability, inbreeding, and ecological variability in these organisms for the first time. Saccharomyces cerevisiae is one of the most important organisms in basic and applied genetic research. Study of its genome has greatly accelerated genomics in other higher organisms, including humans. Surprisingly, however, we know little about the ecology and evolution of S. cerevisiae in nature. This project will answer fundamental questions about the population biology of yeast in nature and will provide a basis for future research integrating evolution, ecology, and genomics using yeast as both a laboratory and a field model organism.