Figure 2.

Endogenous c-di-AMP levels correspond to DNA damage. (A) HPLC analysis of extracts from PY79 (wild type) and YA5 (ΔdisA) cells and commercially available c-di-AMP (see Methods section). (B,C) Intracellular c-di-AMP concentrations, as determined by HPLC (see Methods section). Each column represents the mean c-di-AMP concentration calculated from three independent biological samples, with bars representing standard deviation. (B) PY79 (wild-type) cells were collected during vegetative (Veg) growth and at 2 h of sporulation. Sporulation was carried out in the presence of 350 μg/ml NAL or 50 ng/ml MMC, as indicated. YA5 (ΔdisA) cells were collected at 2 h of sporulation. (C) PY79 (wild type), YA5 (ΔdisA), YA188 (ΔyybT), MB21 (P_{hyper−spank}-disA; disA o/ex) and YA214 (P_{hyper−spank}-yybT; yybT o/ex) were collected at 2 h of sporulation. c-di-AMP, cyclic diadenosine monophosphate; HPLC, high-performance liquid chromatography; MMC, Mitomycin C; NAL, nalidixic acid.