Fig. 3. cyk-3 embryos fail to redistrubute f-actin but form an actin ring at the presumptive cleavage site. Embyros from either homozygous mutant or wild-type hermaphrodites were dissected directly into fixative containing rhodamine-labeled Phalloidin. DNA is stained with Hoechst 33342 and shown in the small insets. (a) At pronuclear meeting, the actin cytoskeleton of wild-type embryos is confined to the anterior hemisphere, forming the `anterior cap' (surface view). In cyk-3 mutant embryos of the same stage, the actin is homogeneously distributed (surface view). (b) In wild-type embryos at late telophase, a prominent actin-based contractile ring divides the cell into two. In cyk-3 mutant embryos, the actin ring fails to divide the cell (midfocus). However, a ring of f-actin is formed at the right time and site, suggesting that cytokinesis is initiated (surface view, arrow).