(A) Time-lapse analysis of embryos expressing pie-1p::mCherry::TBA-1/α-tubulin (red) and endogenous GFP::GIP-1 (green) and treated at anaphase (t = 0 min) with DMSO (left panels), 30 µM okadaic acid (middle panels), or 60 µM rubratoxin A (right panels). Scale bar, 10 µm. (B–D) Time-lapse analysis of the disassembly of endogenous tagRFP::SPD-5 (red); SPD-2::GFP (green) starting from cytokinetic furrow ingression (t = 0 min) in the one cell embryo as represented on the cartoon below. Timing of rupture (light gray arrow) at this stage is indicated. Images show posterior (P) embryonic region (black dotted box in cartoon) containing the posterior centrosome (red dot in cartoon). Embryos are treated with lacZ(RNAi) (control, (B), let-92(RNAi) (C), or let-92(RNAi) +gpr-1/2(RNAi) (D). Note the appearance of SPD-2 in packets (C, magenta arrowheads) following let-92 RNAi treatment. Scale bars, 10 µm. (E–F) SPD-2 (E) or SPD-5 (F) intensity at the centrosome during disassembly starting from cytokinetic furrow ingression (t = 0 min) in embryos treated with lacZ(RNAi) (control, grey, n = 8), let-92(RNAi) (orange, n = 8), or let-92 +gpr-1/2(RNAi) (navy, n = 8). SPD-2 disassembly slope (E, 0 to 4 min, black dotted lines): control (slope = −2.31e+6, r2 = 0.97), let-92(RNAi) (slope = −8.60e+5, r2 = 0.94) and let-92 +gpr-1/2(RNAi) (slope = 1.67e+5, r2 = 0.86). SPD-5 disassembly slope (F, 2 to 4 min, black dotted lines): control (slope = −5.65e+6, r2 = 0.95), let-92(RNAi) (slope = −7.46e+5, r2 = 0.92) and let-92 +gpr-1/2(RNAi) (slope = −4.40e+5, r2 = 0.91). Slopes are significantly different from each other (t-test, p-value<0.0001). (G) Average centrosomal pixel intensity at the end of disassembly in control (t = 5’, grey, n = 15) and in let-92(RNAi) treated embryos (t = 15’, orange, n = 13). Note that we accounted for centriole duplication defects following let-92 depletion by comparing the average intensity of each individual centriole/centrosome in control embryos (see two SPD-2 foci representing two individual centrioles/centrosomes, light blue arrowheads at t = 5’ in Figure 5B) to intensity of the single centrosome in let-92 depleted embryos (single SPD-2 focus, light blue arrowhead at t = 15’ in Figure 5C; see Material and methods). Asterisks indicate comparison between indicated perturbation and control: *p-value<0.01, ** p-value<0.001, *** p-value<0.0001. ‘a.u.’=arbitrary units. Graphs indicate mean ± s.e.m.