FIG 3.

Impact of DNA damage on spnIII TRD switching. Bars represent the mean percentages and SD within a minimum of 10 hsdSE single colonies for each strain. Recombination can occur on the 333-bp IR (dashed), the 85-bp IR (dotted), and the 15-bp IR (solid gray), and a small number can be generated by >2 recombination events (checked). (A) D39, D39 creX, D39 recA, and D39 creX recA were exposed to a sub-MIC dose of ciprofloxacin, and after 16 to 18 h of growth, colonies were analyzed for recombination events. (B) D39 was exposed to a sublethal dose of UV, and recombination events in 20 single colonies were compared to those of an unexposed control. Significance was tested using two-way ANOVA.