BUB-1 depletion delays anaphase onset independently of checkpoint signaling. (A) Images from time-lapse movies of one-cell C. elegans embryos expressing GFP::H2b (arrow) and γ-tubulin::GFP (arrowheads) for the indicated conditions. Time is given in seconds after NEBD. The asterisks mark extra chromatin present due to defective meiotic segregation. Bar, 5 µm. (B) Immunoblot of bub-1(RNAi) worms next to a dilution of control N2 worms. Numbers indicate the amount loaded relative to the 100% lanes. α-Tubulin is a loading control. (C) Plot of mean NEBD–anaphase onset intervals for the indicated conditions in one-cell embryos. Error bars indicate SD; red broken lines are control values; n is the number of embryos. (D) BUB-1 and BUB-3 kinetochore localization in bub-3Δ (left) and bub-1(RNAi) (right), respectively; n is the number of embryos. The mean integrated fluorescence intensity at kinetochores is plotted; error bars indicate the 95% confidence interval (CI). Bars, 2 µm. (E) Schematic indicates the time intervals measured and plotted below. Error bars indicate SD; red broken lines are control values; n is the number of embryos.