Figure 1.

The UV hypersensitivity of recF and recR is dependent upon the replication state of the cell. (A) The survival of parental (▪, □) SR108, recF (•, ○) HL219, and recR cells (▴, ▵) HL220 is shown after UV irradiation at the indicated dose for both stationary phase (filled symbols) and exponentially growing cultures (open symbols). recF and recR cells are less UV sensitive in stationary phase cultures. (B) The survival of parental (▪, □) SR108, recF (•, ○) SR108F, and recR cells (▴, ▵) SR108R, is shown after UV irradiation at the indicated dose for both cultures pretreated for 3 h with chloramphenicol (filled symbols) and untreated exponentially growing cultures (open symbols). (C) Cells were treated as in (B) for uvrA (▸, ▹) HL758 and uvrC cells (◂, ◃) HL763. Survival curves represent the average from at least 3 independent experiments, except for uvrA and uvrC that were carried out once and twice, respectively.