Analysis of sporulation septation in the wild type and ftsW, ftsI, and ftsQ mutants. Phase-contrast (A) and Fluo-WGA-stained (B) and PI-stained (C) images of aerial hyphae of strain M145 after 48 h of growth showing regular septation and condensed nucleoids in each prespore compartment. In contrast, there is an absence of septation and no chromosomal condensation in panels E and F (Fluo-WGA and PI stained, respectively) showing aerial hyphae of DSCO2085-1 [ftsW::Tn5062(1)] after 96 h of growth and in panels H and I (Fluo-WGA and PI stained, respectively) showing aerial hyphae of DSCO2090 (ftsI::Tn5062) after 96 h of growth. (K and L) Fluo-WGA-strained (K) and PI-stained (L) aerial hyphae of DSCO2083 (ftsQ::Tn5062) after 80 h of growth showing delayed and less-regular septation and only partial nucleoid condensation. Panels D, G, and J are phase-contrast images for the ftsW, ftsI, and ftsQ mutants, respectively. Scale bar, 10 μm.