DNA Adenine Methylation Is Required to Replicate Both Vibrio cholerae Chromosomes Once per Cell Cycle
Figure 4
Effect of Dam depletion in V. cholerae.
Growth of the WT (CVC209/pGD93) and its Δdam derivative (CVC2023) on LB plates (A) or in LB broth (B) either under the permissive (P) condition (media with 0.2% arabinose and incubation at 30°C) or under the restrictive (R) condition (media with 0.2% glucose and incubation at 42°C). (C) The viability and the presence of pGD93 after 7.5 hours of growth in LB broth under the permissive and restrictive conditions. To test for the viability and plasmid stability, the cultures were titered on LB plates with or without ampicillin but otherwise under the permissive condition. The values were normalized with respect to those from the WT strain grown under the permissive condition. (D) Analysis of ori and ter marker frequencies. Cells were from (B) and collected at OD≈0.3. The frequencies of ori and ter markers in WT (black bars) and Δdam (white bars) cells were compared by qPCR. Crossing point (Cp) values were determined in triplicate and used for calculating the oriI/oriII, oriI/terI and oriII/terII and terI/terII ratios.