Table 2.

Median frequencies of spontaneous mutations and DNA slippage events in wild-type strains bearing the msh2-GD693and msh6-GD987 alleles on GAL102μm plasmidsa

Relevant plasmidFrequency
Canavanine resistance assayPoly(GT) tract alteration assay
Median (10−6)Relative to wtMedian (10−4)Relative to wt
Vector1.513.41
pGAL10-MSH2 3.223.41
pGAL10-MSH6 4.02.75.71.7
pGAL10-msh2-GD693 93626920
pGAL10-msh6-GD987 1711175.0
Vector, vector1.21NTNT
pGAL10-MSH2, vector1.81.5NTNT
pGAL10-MSH6, vector2.82.3NTNT
pGAL10-MSH2, MSH6 2.31.9NTNT
pGAL10-msh6-GD987, vector1714NTNT
pGAL10-MSH2, msh6-GD987 1613NTNT
pGAL10-msh2-GD693, vector4437NTNT
pGAL10-msh2-GD693, MSH6 169141NTNT
pGAL10-msh2GD693,msh6GD987 193161NTNT
  • a Strain FY23 (wild type [wt]) was transformed individually or in pairs with pEAE51 (pGAL10-MSH6), pEAE86 (pGAL10-MSH2), pEAE87 (pGAL10-msh2-GD693), and pEAE84 (pGAL10-msh6-GD987) and tested for forward mutations to Canr. Vector refers to control plasmids that lackedMSH2 or MSH6 sequences. These strains were also transformed with pEAA69 [(GT)16-URA3 ARS CEN] and, where indicated, tested in the poly(GT) tract alteration assay described in the Materials and Methods. The median frequency was determined from 11 independent colonies for each experiment. The averages of 2 to 10 independent experiments are presented. NT, not tested.