Cytochalasin-B: time-lapse cinematographic studies on its effects on cytokinesis.

L cells exposed to cytochalasin-B (cyto-B) show the normal development of deep cleavage furrows in both bipolar and multipolar cell divisions Due to the drug-induced inhibition of cellular motility, the resulting daughter cells do not move away from each other but reunite to form multinucleate cells. In mitotic cells from cultures exposed to cyto-B for long periods of time, vigorous blebbing and contraction of the cell surface is seen The evidence from time-lapse studies presented suggests that cyto-B-induced multinucleate cells are formed, not by the failure of the cleavage furrow, but by the drug-induced changes in surface activity and motility of cells after division.