GPR-1/2 is critical for regulating proper abscission after furrow ingression. (A–D) Representative pseudokymographs of the division plane (depicted on the top right) acquired by time-lapse confocal microscopy of embryos coexpressing GFP^Mem./Tub.;mCherry^Chr./Cent. that are treated with gpr-1/2(RNAi) (A), aspm-1(RNAi) (B), spd-1(ts) embryos that are treated with gpr-1/2(RNAi) (C), or spd-1(ts) embryos that are treated with aspm-1(RNAi) (D), as indicated. For comparative analysis, only GFP^Mem./Tub. localization is shown. gpr-1/2(RNAi) (n = 8); aspm-1 (RNAi) (n = 8); gpr-1/2(RNAi) in spd-1(ts) background (n = 15) (also see corresponding Video 13); aspm-1(RNAi) in spd-1(ts) background (n = 11). n is the number of embryos analyzed. Note that aspm-1(RNAi) embryos in spd-1(ts) background do not show any abscission failure; however, spd-1(ts) embryos that are treated with gpr-1/2(RNAi) show 60% abscission failure. The pseudokymograph starts at 250 s w.r.t NEBD. The scale bar is 5 µm. (E–H) Graphs represent furrow ingression kinetics of embryo coexpressing GFP^Mem./Tub.;mCherry^Chr./Cent. in gpr-1/2(RNAi) embryos (E), aspm-1(RNAi) embryos (F), gpr-1/2(RNAi) embryos in spd-1(ts) mutant background (G), and aspm-1(RNAi) embryos in spd-1(ts) mutant background (H). Please note furrow ingression followed by regression in spd-1(ts) mutant embryos that are depleted for GPR-1/2. A similar observation was made for spd-1(ts) mutant embryos depleted for LIN-5 (see Fig. 5). n is the number of embryos analyzed. Time is w.r.t. NEBD.