Comparative effects of caffeine, its analogues and calcium deficiency on cytokinesis

The effects of caffeine, aminophylline, caffeic acid, and calcium deficiency on cytokinesis were studied by light and electron microscopy. All these treatments blocked cell plate formation, resulting in the formation of binucleate cells. The aggregation and organization of membranous vesicles at the ‘presumptive cell plate’ during these treatments appears similar to that of normal cells, but fusion of the vesicles is insufficient to form a complete cell plate. It is suggested that some aspect of membrane recognition and fusion is the process actually interfered with by these treatments. Greater numbers of binucleate cells and fewer partial cell plates were observed in cells treated with caffeine and aminophylline as compared with those exposed to caffeic acid or calcium deficiency, indicating that the latter treatments do not block cell plate formation as efficiently as the former.