Aggregation during sexual development in Dictyostelium discoideum

Abstract

A microcinematographic analysis of the behavior and movements of cells and cell masses in mated cultures (NC4 .times. V12) of D. discoideum indicates that a chemotactic process directs cell aggregation during macrocyst development. Zygote giant cells form before aggregation begins and act as the aggregation centers. Young multicellular macrocyst stages are sources of cyclic AMP, and amoebae from macrocyst cultures orient chemotactically to cyclic AMP. The data, coupled with other characteristics such as pulsatile streaming, suggest that the aggregation process leading to macrocyst development is the same as that occurring during fruit construction. Other aspects of sexual development are also discussed. A model was proposed for the sequence of events leading to macrocyst development in D. discoideum.