Fig. 7. PAL-1 immunolocalization in par; mip(RNAi) double mutant embryos. Strains mutant for the gene indicated above each column were injected with dsRNA (left) (see Fig. 2A for quantitative summary of staining experiments). (A) par-3 mutants express PAL-1 in variable patterns, including in all four blastomeres, as shown. (B,C) par-1 and par-4 mutants do not express PAL-1. (D-F) All double mutants that include mex-6(RNAi) express PAL-1 at a high level in all four blastomeres. (G,H) par-3; spn-4(RNAi) embryos and par-1; spn-4(RNAi) embryos express PAL-1 in all four blastomeres. The characteristic par-3 cell arrangement (evident in A,D) was suppressed by spn-4(RNAi) in 9/10 (G) par-3; spn-4(RNAi) embryos. (I) par-4; spn-4(RNAi) embryos do not express PAL-1. We observed that par-4; spn-4(RNAi) embryos, like par-4; mex-3(RNAi) embryos (see Fig. 1), often failed to complete early cell cycle events normally, including nuclear division and cytokinesis.