Figure 1.

DNA Pol II spontaneous mutant frequencies in wild-type and antimutator Pol III genetic backgrounds. All strains were mutL::Tn5. We measured spontaneous mutant frequencies to rifampicin and nalidixic acid resistance at the rpoB and gyrA loci, respectively, in various polB and dnaE backgrounds. The data represent an average of the medians from three experiments, each with 10–20 independent cultures grown from two to three isolates. Error bars indicate ±95% confidence intervals for the medians.