Table 3.
Spontaneous frequencies (f) and mutation rates (μ) in wild-type and PNP-deficient strainsa
| Rifr |
Nalr |
|||
|---|---|---|---|---|
| WT | PNP-deficient strain | WT | PNP-deficient strain | |
| f (×108) | 3.7 (3.0–4.6)b | 2.9 (2.3–3.8) | 0.46 (0.23–0.69) | 0.39 (0–0.79) |
| μ (×108) | 0.81 (0.68–0.96) | 0.68 (0.57–0.85) | 0.15 (0.090–0.21) | 0.14 (0–0.24) |
a
The rpoB mutation frequencies (f) per cell were calculated by dividing the median number of mutants by the average number of cells in a series of cultures, and the mutation rates (μ) were determined with the method of Drake (17) (see Materials and Methods).
b
Values in parentheses are 95% confidence limits.