Fig. 9. Treatment with U73122 (U7) results in depletion of cleavage furrow F-actin. Confocal fluorescence micrographs of crane fly primary spermatocytes stained with Alexa-488 phalloidin to visualize F-actin. Each illustration is of a summed Z-series of confocal images. (A,B,C) Control cells in (A) late anaphase, (B) later anaphase and (C) telophase. (D) Cell treated with Li⁺. (E) Cell treated with LY. (F,G) Cells treated with U7. Actin filaments appear normal in all cells except for those treated with U7, in which patchy cortical actin is prominent at the poles and actin filaments are absent or greatly reduced at the equator (F,G). Bar, 10 µm.