Figure 3. csp-1B cell-killing activity is not regulated by the canonical programmed cell death pathway.

(A–D) The percentages of PLM cells that survive in strains carrying P_mec-7::ced-3, P_mec-7::csp-1B or P_mec-7::ced-4 transgenes. (A) ced-9 protects against ced-3- but not csp-1B-cell-killing transgenes. (B) The cell-killing activity of csp-1B transgenes is mostly independent of ced-3 and ced-4. The cell-killing activities of (C) ced-3 and (D) ced-4 transgenes do not require csp-1. PLM survival was scored based on the presence of GFP expressed from the mec-3 promoter. Asterisks indicate p<0.05 in a Fisher's exact test. All strains in (A) contained ced-3(n3692). (E) A model depicting the genetic pathways regulating the caspase genes csp-1 and ced-3 (see text).