Document Type

Article

Publication Title

Proceedings of the National Academy of Sciences of the United States of America

Publication Date

8-17-1999

Volume

96

Issue

17

Disciplines

Biology | Life Sciences

Abstract

Culturing a population of Saccharomyces cerevisiae for many generations under conditions to which it is not optimally adapted selects for fitter genetic variants. This simple experimental design provides a tractable model of adaptive evolution under natural selection. Beginning with a clonal, founding population, independently evolved strains were obtained from three independent cultures after continuous aerobic growth in glucose-limited chemostats for more than 250 generations. DNA microarrays were used to compare genome-wide patterns of gene expression in the evolved strains and the parental strain. Several hundred genes were found to have significantly altered expression in the evolved strains. Many of these genes showed similar alterations in their expression in all three evolved strains. Genes with altered expression in the three evolved strains included genes involved in glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, and metabolite transport. These results are consistent with physiological observations and indicate that increased fitness is acquired by altering regulation of central metabolism such that less glucose is fermented and more glucose is completely oxidized.

Keywords

Adaptive evolution, Chemostat, DNA microarrays, Glucose metabolism

DOI

https://doi.org/10.1073/pnas.96.17.9721

Rights

© 1999 The National Academy of Sciences

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