Comparison of spontaneous and adaptive mutation spectra in yeast

Adaptive mutations occur in nongrowing populations of cells to overcome strong, nonlethal selection conditions. Several models have been proposed for the molecular mechanism(s) for this phenomenon in Escherichia coli, but the mechanisms involved in adaptive mutagenesis in the yeast Saccharomyces cerevisiae are largely unknown. We present here a comparison of the mutational spectra of spontaneous and adaptive frameshift reversion events in yeast. In contrast to results from E. coli, we find that the mutational spectrum of adaptive mutations in S. cerevisiae is not similar to that seen in mismatch repair defective cells, but rather resembles the spontaneous mutational events that occur during normal growth.

Duke Scholars

Author Sue Jinks-Robertson Molecular Genetics and Microbiology