TABLE 1.
Mutation rates in srs2 mutant strainsa
| Mutation (exponent) and genotype | Mean no. of mutations/cell generation, 10−n (± SD) | Ratio (fold over wild type) |
|---|---|---|
| Expansions of (CTG)13 (10−7) | ||
| SRS2 | 1.4 (± 0.2) | 1.0 |
| srs2::LEU2 | 56 (± 11) | 40 |
| srs2::TRP1 | 62 (± 11) | 44 |
| srs2::LEU2 + pSRS2 | 1.8 (± 0.8) | 1.3 |
| rad51::kanMX | 1.3 (± 0.5) | 0.9 |
| srs2::TRP1 rad51::kanMX | 16 (± 0.6) | 11 |
| rad52::LEU2 | ≈1 | ≈0.7 |
| srs2::TRP1 rad52::LEU2 | 46 (± 5) | 33 |
| pol32Δ | 41 (± 3) | 29 |
| srs2::LEU2 pol32Δ | 28 (± 12) | 20 |
| pol32Δ + high-copy SRS2 | 2.0 (± 0.5) | 1.4 |
| srs2::LEU2 + psrs2K41A | 24 (± 9) | 17 |
| sgs1::kanMX4 | 2.4 (± 0.5) | 1.7 |
| srs2::LEU2 + high-copy SGS1 | 60 (± 11) | 43 |
| Expansions of (CTG)25 (10−5) | ||
| SRS2 | 1.0 (± 0.3) | 1.0 |
| srs2::LEU2 | 4.9 (± 0.8) | 4.9 |
| srs2::TRP1 | 5.1 (± 1.1) | 5.1 |
| srs2::LEU2 + low-copy pSRS2 | 1.4 (± 0.2) | 1.4 |
| Expansions of (CAG)25 (10−7) | ||
| SRS2 | <5 | 1.0 |
| srs2::LEU2 | 23 (± 0.7) | 4.6 |
| Expansions of (CGG)25 (10−5) | ||
| SRS2 | 6.8 (± 0.7) | 1.0 |
| srs2::LEU2 | 23 (± 5) | 3.4 |
| Dinucleotide repeat mutations (10−5) | ||
| SRS2 | 3.8 (± 0.2) | 1.0 |
| srs2::LEU2 | 4.3 (± 0.3) | 1.1 |
| msh2Δ | 1,400 (± 10) | 370 |
| CAN1 forward mutations (10−7) | ||
| SRS2 | 3.0 (± 0.4) | 1.0 |
| srs2::LEU2 | 3.7 (± 0.3) | 1.2 |
| rad27Δ | 180 (± 10) | 60 |
| Contractions of (CTG)25+8 (10−5) | ||
| SRS2 | 2.7 (± 0.2) | 1.0 |
| srs2::LEU2 | 2.5 (± 0.3) | 0.9 |
| srs2::TRP1 | 2.2 (± 0.4) | 0.8 |
a
Rates were determined by the method of the median(20). Rates are the averages of three to six determinations for genetically independent clones. The exponent is shown separately for each section. The ratio value is the mutation rate for the indicated genotype divided by the wild-type rate.