Acidification of phagosomal lumen is defective in unc-108(n3263) mutants. (A) DIC (a and b) and corresponding fluorescence (c and d) images showing 2× FYVE::GFP circles around germ cell corpses induced by γ-ray irradiation in adult hermaphrodites. The midbody is shown on the left and the dorsal side faces up. (B) DIC (a and b) and fluorescence (c and d) images of dissected gonads stained with Lysosensor DND-160 after γ-ray irradiation. Arrows indicate germ cell corpses or the corresponding phagosomes. Bars, 20 μm. (C) Quantification of the acidification defects in unc-108(n3263) mutants. The numbers of DIC(+) cell corpses and 2× FYVE::GFP phagosomes are reported as mean ± SD (n = 15). Bright, intermediate, and no Lysosensor staining correspond to a phagosome/germline signal intensity ratio of ≥2.0, >1.1 and < 2.0, and ≤1.1, respectively. For each genotype, 33 phagosomes were scored.