FIG. 5.

Early and asynchronous initiation of replication in spo0J mutant cells. spo0J⁺ (A, strain CRK6000) and spo0J mutant (B, strain NIK6074) cells were grown in Difco antibiotic medium 3, and samples were taken during exponential growth and treated for analysis by flow cytometry (see Materials and Methods). Histograms show the number of cells with a given amount of DNA per cell after completion of rounds of replication, as determined by flow cytometry. The numbers on the x axis represent the number of origins per cell at the time the sample was taken. More than 20,000 cells were analyzed in each experiment.