Synthetic effect of the CYK-4 GAP mutation and depletion of LIN-5/NuMA or GPR-1/2/Pins/LGN. (A) Stills from the live imaging of embryos of the indicated genotypes by DIC microscopy. While the cyk-4(or749) embryos, which failed cytokinesis due to late regression of the cleavage furrow, could form a furrow that deepened beyond 50% (cyan arrowheads in A), the additional depletion of LIN-5 or GPR-1/2 severely prevented this (B), allowing only very shallow furrowing (pink arrows in A).