FIG. 2.

TcaA is required for the nematocidal activity of W22730. Feeding of C. elegans on a tcaA deletion mutant (W22730 ΔtcaA) resulted in an OP50-like survival curve (TD₅₀ of 13.4; number of nematodes, 65) that significantly (P < 0.0001) differs from that of strain W22730. The wild-type-like phenotype could be restored using plasmid pACYC184/F37.R43(s) harboring tcaA. Average data of three independent experiments are shown (Table 2). No significant difference (P = 0.1277) between the survival curves following exposure to W22730 or W22730 ΔtcaA/pACYC184/F37.R43(s) was observed. The survival curves for nematodes feeding on W22703 and E. coli OP50 are identical to those in Fig. 1 and 5.