Mutation Rates (×10−7) of pol3-eex Mutant Strains.

Rates of FOA or canavanine resistance (FOAr or Canr mutants per cell division) were determined by fluctuation analyses and maximum likelihood estimates using data from multiple independent experiments (except where noted). eex alleles are arranged from top to bottom in the same order as Table 1. Confidence intervals (95%) are in parentheses. A dash (–) indicates the mutation rate was not determined.aMutation rates were determined in two different strains: FOAr, BP4001; Canr, YP6.bMutation rates were determined in strain MP4.cpol3-eex alleles not analyzed: L411R, L531P, I616C, D643N, A677T, and P719T.dMutation rate from a single experiment.eThe fold-increase in mutation rate caused by loss of Pol δ proofreading (pol3-01 effect) was calculated by dividing each pol3-01,eex msh6Δ mutation rate (Table 1) by the corresponding pol3,eex msh6Δ rate (above). pol3,eex msh6Δ strains marked with an asterisk (*) have mutation rates within 2-fold of the POL3 msh6Δ strain, suggesting the eex alleles do not hamper primer partitioning or exonuclease function. In these strains, pol3-01 increased mutation rate an average of 163-fold.