FIG. 4.
Timing of spore formation during development in redB::Ω4439. A) Spore production during the first 70 h of development. Ten microliters of 2 × 109 cells/ml of wild-type (solid circles), redB::Ω4439 (solid triangles), ΔespA (solid squares), or ΔespA redB::Ω4439 (open diamonds) cells were spotted in triplicate on clone fruiting media and incubated at 32°C. Cells were harvested at the indicated time points, and the number of heat- and sonication-resistant spores (3) was determined. B) ΔespA redB::Ω4439 (DZ4658) cells after 72 h of development pictured at 12× magnification (center panel) and 1,000× magnification of the swarm edge (bottom panel), demonstrating undifferentiated cells and the center of the spot (top panel) showing lawns of spores.