FIG 3.

ΔspoVQ spores are purified less efficiently, produce a thinner cortex layer, and are prone to spontaneous germination. (A) Spore yields from purifications of WT, ΔspoVQ, and ΔspoVQ complementation strains from a minimum of six biological replicates. Yields were determined by measuring the optical density of spore purifications at 600 nm and are expressed in arbitrary units (a.u.). Statistical significance relative to the WT was determined using one-way ANOVA and Tukey’s test. ***, P < 0.0005; **, P < 0.01. (B) Cortex thickness (nm) of the indicated spores based on transmission electron microscopy (TEM) analyses. Measurements were made on a minimum of 85 spores per strain and are representative of two biological replicates. ****, P < 0.0001. (C) TEM of the indicated spores. The orange dashed line highlights the cortex thickness measured. Scale bar represents 100 nm. (D) Spontaneous germination of WT, ΔspoVQ, ΔsleC, and ΔcspC germination mutants and the indicated double mutant spores on rich (BHIS) medium lacking germinant (BHIS alone) and rich medium containing germinant (BHIS + taurocholate [TA]). Germination data are based on analyses of four independent spore preparations. Statistical significance relative to the parental strain is shown and derives from one-way ANOVA analyses and Tukey’s test. ****, P < 0.0001; ***, P < 0.005.