Figure 1.—
The sonB1 mutant is highly sensitive to DNA-damaging agents at 42°. (A) Colony formation of wild-type (R153), uvsB505ATR (CDS314), cdc2F (FRY24), sonA1 (CDS365), and sonB1 (CDS364) strains under the indicated conditions. Plates were incubated for 3 days. Note that the sectoring of the cdc2F mutant at 32° in the presence of DEO or camptothecin is due to loss of the cdc2F allele by plasmid eviction, leaving the wild-type allele. (B) Viability of the indicated strains (250 conidiospores spread/plate, two plates/strain) at 32° and 42° in the presence of different concentrations of the DNA alkylating agent DEO. Viability was assessed after 3 days incubation.