Fig. 3: The canonical divisome components, FtsL, FtsQ, and FtsB, are dispensable for vegetative cell division but are important for asymmetric division.

a Growth profiles of the indicated strains in BHIS. Data are from a single growth curve experiment; mean, and standard deviation curves are plotted from three biological replicates. b Violin plots showing cell length distributions and representative micrographs of cells sampled from BHIS cultures during exponential growth (OD₆₀₀ ~0.5). White circles indicate means from each replicate, black lines indicate average means, and the dotted line indicates the WT average mean for comparison across strains. Data from three biological replicates; >1500 cells per sample. Scale bar, 5 µm. c, d Cytological profiling of sporulating cells sampled from sporulation-inducing 70:30 plates after 18–20 h of growth. Cells were assigned to five distinct stages based on their membrane (FM4-64) and DNA (Hoechst) staining and their phase-contrast morphological phenotypes. For representative micrographs and stage assignment information, see Supplementary Fig. 5b. AD Asymmetric Division, EI Engulfment Initiated, EC Engulfment Completed, PF Phase-bright/dark Forespore, FS Free Spore. White circles indicate means from each replicate, bars indicate average means and error bars indicate standard deviation. *p < 0.05, ***p < 0.0001; statistical significance was determined using an ordinary one-way ANOVA with Dunnett’s test. Data from three independent experiments; >1000 total cells and >100 visibly sporulating cells per sample. Source data with exact P values are provided in the Source Data file. e Bacterial two-hybrid analysis of interactions between components of the predicted polar divisome. The β-galactosidase activity was normalized to the negative control. Mean ± standard deviation from three biological replicates is indicated. The schematic shows interactions between different proteins where lines are colored according to the amount of β-galactosidase activity detected. f Schematic showing FtsL, FtsQ, and FtsB forming a divisome-like subcomplex with SpoVD and SpoVE. This polar divisome contributes to septal PG synthesis during asymmetric division. Created with BioRender.com.