FIG 2.
PAE and chromosome fragmentation. Cultures of S. pneumoniae R6 (A) or R6 ΔspxB (B) containing 108 CFU/ml were treated with antibiotics as described for Fig. 1. DNAs from cells taken at different times in the PAE phase were subjected to pulsed-field gel electrophoresis. CZ, compression zone, the band in which the nicked fragments of chromosomal DNAs that are unresolved in the gel migrate. Quantification of the fragmented chromosome (signal in the CZ relative to the combined signal of the lane plus well) and of the nonfragmented chromosome (signal in the well relative to the combined signal of the lane plus well) relative to time zero is shown. Fold variations (means ± SDs) from three independent replicates are presented. Student t test significances are with respect to time zero. *, P < 0.05; ***, P < 0.0001; ****, P < 0.00001.