Fig. 4.

DAF-16 is necessary for the protective effect of reduced IGF signaling on muscle cells but is not required for the survival of the muscle cells under normal IGF signaling conditions. (A) daf-16 is required for the protective effect of the daf-2(e1370) mutation. Muscle cell death reappeared in the triple mutant, daf-2(e1370);daf-16(mu86);dys-1. The arrows indicate the areas with lost muscle nuclei; 20× objective was used for image acquisition. (B) Quantification of the average muscle cell nuclei. Error bars represent SEM. *P < 0.0001 compared with daf-2, two-tailed Student t test; n = 20. (C) The lifespan of the triple mutant daf-2(e1370);daf-16(mu86);dys-1 was not different from that of the double mutant, daf-2(e1370);daf-16(mu86). Survival data were analyzed using the Kaplan–Meier method. For statistical data and additional independent trials, see Table S1. (D) Loss of DAF-16 did not exacerbate the muscle cell death in the dys-1 mutant under normal DAF-2 function. The average muscle cell nuclei of the double mutant, dys-1;daf-16, were compared with the single mutant, dys-1. Error bars represent SEM. n.s., not significant; two-tailed Student t test; n = 20. (E) The lifespan of the double mutant daf-16(mu86);dys-1 was not different from that of daf-16(mu86). Survival data were analyzed using the Kaplan–Meier method. For statistical data and additional independent trials, see Table S1.