Phagocytic behavior of the predatory slime mold, Dictyostelium caveatum: Cell nibbling

The predatory slime mold, D. caveatum, feeds upon other amoebae by phagocytosis. The D. caveatum amoebae begin feeding upon cells the same size or larger by nibbling pieces of cells. While feeding upon other amoebae as opposed to bacteria, they increase in size. This behavior resembles that of phagocytes in higher organisms. A novel method was used to follow the time course of phagocytosis. A lytic toxin, phallolysin, and mutants resistant to the toxin were utilized in an assay to separate the phagocytes from the prey cells. Since a broad spectrum of cells are sensitive to the toxin, the method has general applicability.