Table 3. Reversion of the lys2:InsE-A14 allele in mlh3 strains.
| Genotype | n | Mutation Rate (×10−7) | Relative to WT | Phenotype |
|---|---|---|---|---|
| MLH3 | 110 | 4.71 (3.87–5.11) | 1.0 | + |
| mlh3Δ | 110 | 26.5 (23.5–30.4) | 5.7 | − |
| mlh3-E31A | 15 | 30.5 (16.7–51.6) | 6.5 | − |
| mlh3-N35A | 15 | 31.2 (25.6–44.4) | 6.7 | − |
| mlh3-A41F | 15 | 27.9 (17.1–34.3) | 6.0 | − |
| mlh3-G63R | 15 | 23.8 (18.2–37.1) | 5.1 | − |
| mlh3-K80E | 15 | 16.0 (15.1–27.7) | 3.4 | − |
| mlh3-K83A | 15 | 5.24 (3.49–6.34) | 1.1 | + |
| mlh3-R96A | 15 | 14.8 (6.42–40.6) | 3.2 | − |
| mlh3-G97A | 15 | 16.6 (11.8–26.0) | 3.6 | − |
| MLH3 + empty vector | 11 | 4.42 (1.02-6.05) | 1 | + |
| MLH3 + pGAL10-MLH3 | 11 | 39,100 (15,700-79,900) | 8850 | − |
| MLH3 + pGAL10-mlh3E31A | 11 | 47,800 (28,700-85,900) | 10,800 | − |
| MLH3 + pGAL10-mlh3R96A | 11 | 23,500 (5910-38,400) | 5320 | − |
| MLH3 + pGAL10-mlh3G97A | 11 | 96,000 (45,800-156,000) | 21,700 | − |
| mlh1Δ + empty vector | 11 | 218,000 (121,000-283,000) | 49,300 | − |
The lys2:InsE-A14 SK1 strain EAY1062 and mlh3 derivatives (Table 1) were examined for reversion to Lys+. EAY1269 (lys2:InsE-A14, S288c strain) and an mlh1Δ derivative containing the indicated overexpression plasmids were tested for reversion to Lys+. n, the number of independent cultures tested from at least two independently constructed strains. Median mutation rates are presented with 95% confidence intervals, and relative mutation rates compared with the wild-type strain are shown. WT, wild type.