Mutation rates in Pol δ mutant embryonic fibroblastsa

GenotypeMutation rate (10−8)Fold elevation
Pold1+/+4 ± 2 (5)
Pold1+/L604G20 ± 10 (6)5
Pold1+/L604K17 ± 10 (5)4
  • a Spontaneous mutation rates (mean ± standard error) at the Hprt locus were determined by fluctuation analysis by the method of the mean and are expressed as the number of 6-thioguanine-resistant mutants/cell/generation. Two different cell lines derived from different animals were used for each genotype. Plating efficiencies were similar in all lines and were not adjusted. Unless specified otherwise, the value in parentheses is the total number of times the experiment was performed.