FIG. 2.

Flow cytometric analysis of origin content of wild-type V. cholerae (CVC209), of an isogenic recA mutant (CVC250), and of CVC269 (Table 1) before and after induction with 0.2% arabinose, all in M63-plus-glucose medium. Before analysis, log-phase cells were treated with rifampin and cephalexin, which allowed distinct peaks of DNA contents to be seen, representing cells with integral numbers of chromosomes, which equate to number of origins per cell at the time of drug addition. The recA mutant was used to represent asynchronous replication, as is the case in E. coli (33).