Table 2

Mutation rate analysis of mlh3 and other mismatch repair-deficient strains

StrainMutation rate
Thr+Lys+Canr
Wild type1.2  ×  10−8 (1.0)1.0  ×  10−8 (1.0)2.4  ×  10−7 (1.0)
mlh3 3.9  ×  10−8 (3.3)2.2  ×  10−8 (2.2)2.8  ×  10−7 (1.2)
msh3 5.5  ×  10−8 (4.6)2.1  ×  10−8 (2.1)3.1  ×  10−7 (1.3)
mlh3 msh3 5.9  ×  10−8 (4.9)2.9  ×  10−8 (2.9)4.0  ×  10−7 (1.6)
msh6 9.1  ×  10−8 (7.6)2.3  ×  10−8 (2.3)2.9  ×  10−6 (12)
mlh3 msh6 8.2  ×  10−7 (68)4.6  ×  10−8 (4.6)3.1  ×  10−6 (13)
msh2 6.7  ×  10−6 (558)4.8  ×  10−7 (48)2.9  ×  10−6 (12)
mlh3 msh2 5.1  ×  10−6 (425)4.3  ×  10−7 (43)2.9  ×  10−6 (12)
msh3 msh6 5.7  ×  10−6 (475)5.9  ×  10−7 (59)2.7  ×  10−6 (11)
mlh1 5.5  ×  10−6 (458)4.8  ×  10−7 (48)3.9  ×  10−6 (16)
mlh3 mlh1 6.6  ×  10−6 (545)7.9  ×  10−7 (79)3.9  ×  10−6 (16)
pms1 3.6  ×  10−6 (300)5.1  ×  10−7 (51)3.1  ×  10−6 (13)
mlh3 pms1 9.7  ×  10−6 (804)5.0  ×  10−7 (50)5.8  ×  10−6 (21)
  • Mutation rates were calculated by using the method of the median using five independent colonies per experiment. The average of several experiments is presented. The number of tests carried out with each strain is as follows: wild type, five times; mlh3, six times; msh6, mlh3 msh6, and msh3 msh6, three times each; msh3, mlh3 msh3, msh2, and mlh3 msh2, twice each. For mlh1, mlh3 mlh1, pms1, and mlh3 pms1, the test was repeated twice. The fold increase in the mutation rate compared to the wild-type strain is shown in parentheses.