Locomotion of Physarum polycephalum amoebae is guided by a short range interaction with E. coli

Abstract

Studies of the behavior of Physarum polycephalum amoebae have shown that locomotion of these cells is guided by surfaces composed of aggregated bacteria. Amoebae move readily on both E. coli and agar surfaces. However, when a cell migrating on bacteria encounters an edge of the bacterial surface, the orientation of cell movement changes so that the cell maintains contact with bacteria. Time-lapse cinemicrographic studies employing wild type and mutant cells show that this behavior involves short range interactions between amoebae and bacteria, that it is not dependent on variations in the rate of phagocytosis, and that it is not a simple result of constraints on cell movement imposed by adhesive bonds between amoebae and bacteria. These results provide evidence that guidance of cell locomotion depends on active regulation of the cellular force generating system as the amoebae contact surfaces of varying characteristics and, therefore, suggest that this system is amenable to detailed studies of process involved both in cell-cell recognition and in linking such recognition to regulation of cell movement.