Figure 3.

sir-2.1 specifically affects only DNA damage-induced germ cell apoptosis. (A) Germ cell apoptosis induced by the ced-9(n1653) temperature-sensitive loss of function mutation is largely unaffected by loss of sir-2.1. Worms were grown at 15°C until the late L4 stage and then shifted to 20°C. Apoptosis was scored 24 h later. The slight reduction in sir-2.1(ok434); ced-9(n1653) worms is likely due to slightly reduced germ cell proliferation of sir-2.1(ok434) worms. (B) sir-2.1(ok434) has no effect on excessive physiological germ cell apoptosis conferred by the gla-3(op216) mutation. Corpses were scored at 20°C 24 after the L4 stage. (C,D) Developmental apoptosis is not affected by sir-2.1. (C) Apoptotic corpses that persist until the early L1 stage in ced-1(e1735) animals were scored as described (Ellis et al. 1991). (D) Defects in developmental apoptosis were assayed by counting extra cells in the pharynx of old L3/young L4 larvae as described (Ledwich et al. 2000).