Figure 4

Characterization of genome features of the chromosomal and megaplasmid par mutants and ParAm/ParBm overexpression strains. (A) Phenotypes of the strains on complex media (TB) and on TB supplemented with the chromogenic substrates XGlc and XGal. (B) Intracellular β-glucosidase activity measurements of the strains. The Δbgl strain was used as a negative control. The means and the SDs of three independent experiments are shown. (C) Relative chromosome and megaplasmid copy numbers of the individual mutants determined by qPCR. The means and SDs are from three experiments. (D) Pulsed field gel electrophoresis visualizing chromosome and megaplasmid. “L”, lambda ladder; the positions of the chromosome and megaplasmid are indicated with black and white arrows. (E) Schematic drawing of the megaplasmid pTT27. The positions of the primer pairs used for detecting the megaplasmid sequence loss in ΔparAmN-1 are indicated with short black lines and numbers from 1 to 10. The loci on the megaplasmid that have been investigated are indicated with different bars, and their names are on the right panel of the figure. (F) PCR amplification results for the 10 loci indicated in (E) from wild type, ΔparAmN-1 and ΔparAmN-2. The primer pairs 1 to 3, 4 to 7 and 8 to 10 were mixed into three pools, and in each reaction amplification of a chromosomal gene locus (pyrF) was used as a control. The predicted sizes of the PCR products 1 to 10 are 87, 164, 247, 346, 400, 498, 610, 699, 898 and 1014 bp. The size of the control amplicon is 460 bp (white frame). The bands of the 10 PCR products are indicated with numbers 1–10 on the right side of the corresponding figure panel. The gray arc in (E) indicates the megaplasmid region estimated to be lost in ΔparAmN-1.