Fig. 5.

Mutant frequencies induced by ethylating agents: (A) EMS, (B) ENNG and (C) ENU. Strains are NR10832 (wild-type), open circle; KT01121 (ada ogt), open triangle; NR12896 (mutS), closed circle; NR11102 (mutL), open square; NR12897 (mutH), closed square; and NR12999 (uvrA), closed triangle. Mutant frequencies are corrected by subtracting spontaneous mutant frequencies. Statistical analysis was performed using the Student’s t test. **P > 0.01 and *P > 0.05 compared with the mutant frequency for the wild-type.