(A and B) L4 stage worms of wild type (N2) and xpa-1(RNAi), rev-1(tm8701) and rev-1(tm8701); xpa-1(RNAi) were treated with TMP (200 μM) for 40 min and exposed to UV-A light (100 J/m2). Gonads were dissected, fixed, and immunostained at 12 and 24 h using RAD-51 antibody. Scale bar, 10 μm. (C) The number of RAD-51 foci per nuclear focal plane was scored for over 100 mitotic germ cells in each stain. P values: *, P<0.05; **, P<0.01; ***, P<0.001; ns, no statistical significance. See Table S2 for One-way ANOVA analysis.