Figure 2.

Wild-type B. subtilis cells generate small round cells containing DNA. (A) Wild-type cells showing that almost all small round cells contain DNA (black triangles). White triangles indicate two small round cells devoid of DNA. 98.33 ± 0.58% (mean ± SD of three independent experiments; > 250 cells counted each) of small round cells generated from wild-type cells contain DNA, while minicells generated from a B. subtilis minD/divIV double mutant (B) are all devoid of DNA. White triangles point out some minicells. The black asterisk in panel (A) indicates a cell with multiple attempts of sporulation. Cells were grown in S7₅₀ for about 100 and 28 h for wild-type and minD/divIV double mutant cells respectively. (C) Quantification of the frequency of the number of asymmetric divisions occurring per cell generating dwarf cell (s). Scale bars 2 μm.