FIG. 4.
Bacterial ΔsbcCD and ΔsbcCD ΔpolXDr strains show an increased delay in intact genomic DNA restoration and in cell division after γ-irradiation. Strains GY9613 (wild type, panels A and E, squares), GY12219 (ΔpolXDr, panels B and E, diamonds), GY12910 (ΔsbcCD, panels C and E, triangles), and GY12918 (ΔsbcCD ΔpolXDr, panels D and E, circles) grown to an A650 of 1.2 were exposed to γ-irradiation at a dose of 6,800 Gy (panel E, filled symbols) or not (panel E, open symbols), diluted in 2× TGY to an A650 of 0.2, and then incubated in 2× TGY. At different times after irradiation, aliquots were taken to prepare DNA agarose plugs, which were digested with NotI prior to analyses by pulsed-field gel electrophoresis (panels A, B, C, and D), and to measure the number of viable cells per ml of culture (panel E).