Figure 1.
Attenuated age-dependent genomic instability in cells lacking the oncogene homologue SCH9. (A) Chronological survival. Data represent the mean ± SEM (error bars), n = 12–14. (B) Mutation frequency over time in the CAN1 gene (measured as Canr mutants/106 cells, n = 20). (C) Cumulative mutation frequency, measured as Canr mutants/106 cells, calculated from day 1 to day 7 or to day 15 in the wild type (DBY746) and mutants lacking SCH9. Day 7 and day 15 represent the ∼50% survival point of the wild type and sch9Δ population, respectively. n = 20. **, P < 0.01; ***, P < 0.001; ANOVA test, Tukey's test versus wild type (WT) on day 7. (D) GCR frequency (Canr5FOAr mutants/108 cells, n = 10–11). (E) Age-dependent base substitutions (trp1-289 reversion) frequency (n = 8–9). (F) Small DNA insertion/deletion mutations in the lysΔBglII background (EH150 strains, n = 8–9). (G) Budding index of chronologically aging cells (n = 6). (H) Cell cycle profile (FACS) during chronological aging. Strains shown are wild type (DBY746) and sch9Δ. Data represent the mean ± SEM (error bars). *, P < 0.05; **, P < 0.01; ***, P < 0.001; two-tailed t test, sch9Δ versus WT at the indicated time points.