FIG. 2.
Mutation frequencies in outgrown spores and growing cells of different strains. (A) Dormant spores of different strains were heat shocked and germinated, aliquots were taken after 180 min, and frequencies of mutation to Rifr were determined as described in Materials and Methods. (B) Overnight cultures of growing cells of different strains were inoculated into LB medium, and after 180 min of growth the frequencies of mutation to Rifr were determined as described in Materials and Methods. The values are averages ± standard deviations for duplicate determinations in two separate experiments (with different cultures or lots of spores). WT, wild type.