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. 2014 Mar 26;9(3):e92229. doi: 10.1371/journal.pone.0092229

Figure 1. Deletion of the aspC gene decreases the number of origins per cell and the decrease is reversed by extra AspC.

Figure 1

(A) Exponentially growing cells in LB, ABTGcasa or ABTG medium at 37°C were treated with rifampicin and cephalexin for 3–5 generations. The number of fully replicated chromosomes per cell represents the number of origins present at the time of drug addition. Subsequently, cells were fixed in 70% ethanol and analyzed by flow cytometry as described in Materials and Methods. For each analysis, 10000 cells were included. Extra AspC was produced from the plasmid pACYC177-aspC in which the aspC gene is under control of its native promoter. (B) The number of origins per cell in exponentially growing cells in LB, ABTGcasa, ABTG, ABT with aspartate or ABT medium at 37°C was measured as described in A. The average number of origins per cell was plotted as a function of the doubling times. Data points are average of three individual experiments and standard errors are given as error bars.