FIGURE 9. F-Actin is reorganized in mitotic Dictyostelium cells but is not concentrated in the cleavage furrow. Cells were fixed in suspension cultures and stained with DAPI (A,C,F,I,K,L) and rhodamine-phalloidin (B,D,E,G,H,J,L,M,O,P). During interphase (recognized by the large, decondensed nuclei) F-actin is concentrated in filopodia, crowns and ruffles of both wild-type and racE null cells (A-B and I-J). During mitosis, both cell types loose their crowns and ruffles and are covered by many filopodia (C-H and K-P). F-actin is not particularly concentrated at the cleavage furrow of dividing cells. (A-H) Wild-type cells; (I-J) racE null cells