Knocking down <i>flr-4</i> increases life span in a food-type-dependent manner.

(A) Knocking down flr-4 by RNAi increases life span. (B) The flr-4(n2259) allele has increased life span that is not further extended when flr-4 is knocked down using RNAi. (C) The flr-4(n2259) allele has increased life span only when the mutant worms are maintained on E. coli HT115 but not on E. coli OP50. (D) Knocking down flr-4 using an OP50-based RNAi system increased life span comparable to HT115-based RNAi. Life spans were performed at 20°C.