Innate immunity mediated longevity and longevity induced by germ cell removal converge on the C-type lectin domain protein IRG-7
(A) The irg-7(zc6) mutation increases the expression of the T24B8.5::gfp atf-7 target gene reporter (Mann-Whitney, P<0.0001). This increased expression by irg-7(zc6) is similar to that induced by exposure to HB or EF bacteria (Mann-Whitney, P = 1.00 and P = 0.98 respectively). Asterisks mark Mann-Whitney values <0.001 compared to the fluorescence in wild-type animals on OP50 bacteria. 30 animals were analyzed per genotype. Error bars represent SE of 3–5 independent biological replicates. (B) The irg-7(zc6) mutation did not extend the lifespan of animals treated with atf-7 RNAi (Mantel-Cox, P = 0.07). Mean survival is indicated within the graph. See S4 Table for additional lifespan data. (C) atf-7(gk715); irg-7(zc6) double mutants animals did not survive on HB bacteria better than atf-7(gk715) single mutants (Mantel-Cox, P = 0.9). Mean survival is indicated within the graph. See S4 Table for additional survival data. (D) Representative fluorescence micrographs (100-fold magnification) of day-1 adults harboring an integrated Phsp-4::gfp transgene. atf-7 and pmk-1 RNAi significantly reduced the expression of the Phsp-4::gfp in irg-7(zc6) mutants. Asterisks mark Student's T-test values of P<0.002 compared to fluorescence on control RNAi. 30 animals were analyzed per genotype. Error bars represent SE of 3 independent biological replicates.