TABLE 3.

Mutant frequencies in dnaQ⁺/dnaQ diploid strains^a

Genotype	No. of Rifr mutants/106 cells
Wild type	0.16
dnaQ991/dnaQ+	0.15
dnaQ991/dnaQ+ spq-2	0.41
dnaQ903::tet/dnaQ+	0.10
dnaQ903::tet/dnaQ+ spq-2	0.37

^aStrains were constructed as described in the text and the legend to Table 2. Cells were grown overnight at 43°C in LB broth, plated on LB and LB Rif plates, and incubated at 43°C overnight. Plating at 37°C yielded similar results.