Figure 1.

Life cycles of solitary and social amoebas. The eukaryote division Amoebozoa consists mainly of unicellular amoebas that enter into a dormant encapsulated cyst stage when experiencing starvation or other forms of stress. Instead, the dictyostelid social amoebas aggregate to form fruiting bodies with dormant encapsulated spores. Taxon groups 1, 2 and 3 mostly use glorin as attractant, and all cells in the aggregate first differentiate as prespore cells, with those at the tip re-differentiating into stalk cells. Many species in these groups can also still form cysts. Group 4 Dictyostelia lost encystation, but gained an intermediate migrating slug stage, and differentiation of prestalk cells and of three new cell types to support the stalk and spore head. This group uses cAMP as attractant for aggregation.