The san-1(ok1580);hcp-1(RNAi) embryos have normal and abnormal kinetochore and centriole structure. Analysis of metaphase blastomeres of wild-type (A-D), hcp-1(RNAi) (E-H), san-1(ok1580) (I-L) and san-1(ok1580);hcp-1(RNAi) embryos (M-T) was assayed. The MPM-2 antibody recognizes mitotic proteins located at the kinetochore and centrioles. Two typical san-1(ok1580);hcp-1(RNAi) metaphase blastomeres are shown. The metaphase blastomere shown in Q-T is of abnormal structure. Bar = 10 μm.