Figure 1.

Frequency of spontaneous mitochondrial mutants: the wild-type (WT) and isogenic ogg1 null mutant (ogg1) were grown, the cells were washed, diluted in sterile water and plated. The ade2 auxotrophic wild-type strain forms red colonies on YPD (containing glucose) and grow on YPG (containing glycerol). If red colonies lose their mitochondrial function they turn white and appear as petite colonies that do not grow on YPG. The number of independent cultures used in the study is shown in parentheses.