DPA accumulation during sporulation of wild-type and spoVAEa and spoVAF mutant spores. Spores of strains PS533 (wild type), PS4348 (spoVAEa mutant), and PS4351 (spoVAF mutant) were sporulated in liquid 2× SG medium and 37°C. At various times, samples were taken, washed, and extracted and DPA was analyzed in extracts as described in Materials and Methods. Time zero is the time when cultures were inoculated to an OD600 of ∼0.1. Symbols: ○, wild type; ●, spoVAEa mutant; △, spoVAF mutant.