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Multiple Duplications Of Yeast Hexose Transport Genes In Response To Selection In A Glucose-Limited Environment, Celeste J. Brown, Kristy M. Todd, R. Frank Rosenzweig

Biological Sciences Faculty Publications

When microbes evolve in a nutrient-limited environment, natural selection can be predicted to favor genetic changes that give cells greater access to limiting substrate. We analyzed a population of baker's yeast that underwent 450 generations of glucose-limited growth. Relative to the strain used as the inoculum, the predominant cell type at the end of this experiment sustains growth at significantly lower steady-state glucose concentrations and demonstrates markedly enhanced cell yield per mole glucose, significantly enhanced high-affinity glucose transport, and greater relative fitness in pairwise competition. These changes are correlated with increased levels of mRNA hybridizing to probe generated from the …