A. Chronic exposure of mms1Δ mutants to DNA damaging agents: five-fold serial dilutions of cells were plated on YES agar containing the indicated DNA damaging agent and incubated at 30°C for 3 days.
Acute exposure to DNA damaging agents: survival curves of mms1Δ and mms1Δmms22Δ mutants exposed to increasing doses of IR. 500-1000 cells were plated on YES agar in triplicate and immediately exposed to the indicated dose of IR or UV irradiation. Colony numbers were counted following incubation at 30°C for 3 days and the mean colony number for each dose represented graphically (with untreated normalized to 100% survival). The sensitivity of an rhp51Δ mutant was analyzed as positive control.
B. Genetic epistasis between Mms1 and Mms22. Five-fold serial dilutions of cells were exposed to the indicated DNA damaging agent and incubated at 30°C for 3 days.