Fig. 2. Role of ced-9 in lin-35-dependent germ cell apoptosis. (A) The loss of lin-35 function suppresses germ cell apoptosis caused by the partial loss of ced-9 function. DIC and fluorescence images of gonad arms of ced-9(n1653ts) and lin-35(n745); ced-9(n1653ts) C. elegans hermaphrodites. Both strains were homozygous for the P_lim-7ced-1::gfp integration bcIs39. White arrows point to apoptotic germ cells. (Aa) Gonad of a ced-9(n1653ts) hermaphrodite that is severely damaged. (Ab) Gonad of a ced-9(n1653ts) hermaphrodite that is not severely damaged but contains a large number of apoptotic germ cells. (Ac,Ad) Gonads of lin-35(n745); ced-9(n1653ts) hermaphrodites that are not severely damaged and contain low numbers of apoptotic germ cells. (B) The dosage of ced-9 determines the level of constitutive germ cell apoptosis. Constitutive germ cell apoptosis was analyzed 40 hours post the L4 stage. Average numbers of apoptotic germ cells per gonad arm are shown. Error bars represent standard deviations of three independent experiments. For each genotype, a minimum of 20 animals was scored blind (n=20-51). The complete genotype of the animals was: ced-1(e1735) [control (+/+)], ced-1(e1735); nDf20; nDp2[unc-86(e1416)] (+/-), ced-1(e1735); nDf20/dpy-17(e164); nDp2[unc-86(e1416)] (+/+) and ced-1(e1735); dpy-17(e164); nDp2[unc-86(e1416)] (+/+/+).