Effects of induction of endocytosis on adhesiveness ofAmoeba proteus

Summary The adhesive behaviour ofAmoeba proteus during induction of endocytosis has been studied with interference reflection microscopy. Although phagocytosis and pinocytosis, jointly termed endocytosis, are closely related phenomena, it was found that the way they affect adhesiveness of amoebae differs substantially. Phagocytosis is accompanied by an increase in area of cell surface contacting the substratum, whereas during pinocytosis a sharp decrease of contact area is observed. The resistance to detachment increases in prey-stimulated and phagocytosing amoebae but declines as the pinocytosis is being induced. These results suggest that the influence of the induction of phagocytic activity on the cell periphery differs from that of induction of pinocytosis.