ROLE OF CYCLIC AMP IN THE POLARIZED MOVEMENT OF THE MIGRATING PSEUDOPLASMODIUM OF DICTYOSTELIUM DISCOIDEUM

Cyclic AMP is known to act as a chemotactic agent that directs the movement of aggregating Dictyostelium discoideum cells. Its role in the multicellular organization of this organism was studied with special reference to the polarized movement of the migrating pseudoplasmodium (slug). The results showed that the tip of the slug has the ability to function as an aggregation center, and that slug cells are chemotactically sensitive to cyclic AMP. The addition of calcium or magnesium appeared to enhance formation of cell streams, thus facilitating detection of chemotactic response of slug cells, but this addition was not required for the response itself. These indicate that the polar movement of the slug may be principally controlled by cyclic AMP.