Loss of DNA in the terminus region of <i>recB</i> mutant requires cell division.

<p>Sequence read frequencies of exponential phase cells normalized to the total amount of reads were calculated for each strain. <u>A and B</u>: Ratios of normalized reads in <i>fts recB</i> mutants at 30°C over 42°C are plotted against chromosomal coordinates. The drop of reads ratio in the <i>dif/TerC</i> area reflects the reads deficit at 30°C (mainly active cell division) versus 42°C (mainly inactive cell division). <u>C and D</u>: Ratios of normalized reads in <i>recB</i> over <i>fts recB</i> mutants at 42°C are plotted against chromosomal coordinates. The drop of reads ratio in the <i>dif/TerC</i> area reflects the reads deficit in the <i>recB</i> mutant at 42°C (active cell division) <i>versus</i> the <i>fts recB</i> mutants at 42°C (mainly inactive cell division). Note an increased ratio of reads around <i>TerA/D</i>, which corresponds to a deficit of <i>Ter</i> sequences in <i>fts recB</i> mutants (shown in panels E to H). Presumably owing to a partial cell division impediment in the <i>fts recB</i> mutants at 30°C, the expected increased ratio is only slightly visible in panel B and not in panel A. <u>E to H</u>: Ratios of normalized reads in <i>recB</i> mutants over isogenic RecB⁺ are plotted against chromosomal coordinates. The weak remaining reads deficit in the <i>dif/TerC</i> region is <i>tus</i> independent and could result from incomplete division blockage by <i>ftsAts</i> and <i>ftsIts</i> mutations. The reads deficit around <i>TerA/D</i> in both <i>fts</i> contexts and the reads deficit around <i>TerB/C</i> in the <i>ftsIts</i> context disappear in the <i>tus</i> mutant. Profile ratios of the terminus region are enlarged and profiles of the corresponding entire chromosomes are shown in insets. Original normalized profiles used to calculate ratios are shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006895#pgen.1006895.s005" target="_blank">S5</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006895#pgen.1006895.s006" target="_blank">S6</a> Figs. The positions of <i>dif</i> (red arrow), and of <i>Ter</i> sites that arrest clockwise forks (<i>TerC</i>, <i>TerB</i>, green arrow) and counter-clockwise forks (<i>TerA</i>, <i>TerD</i>, blue arrow) are shown.