FIG 5.

Effect of the deletion or overexpression of recA1 on the mutation frequencies of the DK1622 and IA strains. The relative expression of imuA or recA1 determined by RT-PCR is listed at the bottom. Expression of the gapA gene was used as a quantitative control of cDNA. DK1622 (wild type), M. xanthus DK1622; IA (ΔimuA), imuA deletion mutant; RA1 (ΔrecA1), recA1 deletion mutant; I⁻ R⁻ (ΔimuA ΔrecA1), imuA-recA1 double-deletion mutant; RA1⁺ (DK1622::recA1), recA1 overexpression strain; I⁻ R⁺ (ΔimuA::recA1), recA1 overexpression in IA. Error bars indicate the standard deviations (SD) from four independent experiments.