Fig. 3.

Elevated spontaneous mutagenesis in yeast strains expressing pol3-R696W requires a DUN1-dependent increase in dNTP levels. (A) Mutations in the RNR regulation pathway modulate the mutator effect of pol3-R696W. Mutation rates are medians for at least 18 cultures. The fold change in the mutation rate relative to the wild-type strain is displayed above the bars. Error bars denote the 95% confidence intervals. The data are from Table S1. (B) Intracellular dNTP levels in strains assayed in A. The dNTP concentrations were measured in asynchronous logarithmic phase cultures, as described in Materials and Methods. The values are the mean and SE of three measurements, each performed with an independently created isolate. All strains assayed in A and B are haploids containing pPOL3.