Fig. 3.

Reduced DAF-2 function prevents muscle cell death in the dys-1 mutants. (A) A reduction-of-function mutation, daf-2(e1370), improved the muscle pathology of the dys-1 mutant. Aggregated GFP was not found in the muscle cells of the dys-1(eg33);daf-2(e1370) and daf-2(e1370) animals on days 8 and 15 of adulthood. Muscle cells were visualized with ccIs4251 as in Fig. 1. The animals were grown synchronously at 20 °C. (Scale bars: 20 μm in a, b, e, and f, and 5 μm in c, d, g, and h.) (B) The average number of muscle nuclei was quantified, as in Fig. 1F (n = 20). Error bars represent SEM. *P < 0.0001 compared with N2; n.s., not significant compared with N2; two-tailed Student t test. (C) daf-2(e1370) extended the lifespan of the dys-1 mutant animals. Survival of the daf-2(e1370), daf-2(e1370);dys-1(eg33), and daf-2(e1370);dys-1(cx18) animals was analyzed using the Kaplan–Meier method. For statistical data and additional independent trials, see Table S1. (D) Reduction of DAF-2 by RNAi feeding protected the dys-1(eg33) mutant from the loss of muscle nuclei. The dys-1(eg33) animals were treated with either a control (empty vector, n = 20) or daf-2– (n = 15) feeding RNAi, and the muscle nuclei were counted on day 4 of adulthood. Error bars represent SEM. *P < 0.0001, two-tailed Student t test. (E) A reduction-of-function mutation, daf-2(e1370), improved the mobility of the dys-1 mutants. Day-7 adulthood animals were transferred to freshly seeded plates, and their speeds were measured immediately as in Fig. 1A. Error bars represent SEM. *P < 0.0001, two-tailed Student t test; n > 20. For video, see Movies S1 and S2.