Flow cytometer study of anterior-like cells in Dictyostelium discoideum.

The Dictyostelium discoideum asexual fruiting body consists of spores, stalk and basal disk cells. Recently, a fourth cell class has been proposed. It has been suggested that these cells originate from anterior-like cells that remain undifferentiated. Anterior-like cells are randomly distributed among prespore cells in the posterior part of the slug. Here monoclonal antibodies that recognize the surface of prespore cells (MUD1), and spores (MUD3) are used in a quantitative flow cytometer assay to demonstrate that this fourth cell class does not exist in the mature fruiting body. However, the tip cells are slow to differentiate, and hence immature fruiting bodies contain a small population of undifferentiated tip cells. We confirm that anterior-like cells represent a large percentage of the non-prespore cell population in the slug. In this report we were unable to distinguish these anterior-like cells from prestalk cells on the basis of size or monoclonal antibody staining.