Figure 3. FIGURE 3: Developmental loci in B. subtilis.

Diagram of the sporulation-germination cycle, with the different classes of developmental loci noted (in parentheses). The spo loci are required for spore formation, but not for vegetative growth. The ger loci are required for proper spore germination. After germination, metabolism is reactivated and the spore transforms into a growing vegetative cell in a process called outgrowth, which is thought to depend on the same pathways that control vegetative growth. The cot and ssp loci were identified after the isolation and characterization of coat and small acid-soluble proteins (SASPs), respectively, from spores. In addition to the these categories, there are hundreds of developmentally-regulated genes whose roles in sporulation and germination are not yet understood. Membranes, red; DNA, blue; cell wall, gray; spore cortex, light gray; spore coat, black; SASPs, green circles.