Figure 1

The life cycle of two Dictyostelium species. Both species have a similar developmental lifecycle until the slug stage. The darker cells are the spore cells and the lighter cells are the stalk cells. 1) The cells eat bacteria and reproduce asexually. 2) Upon starvation, the cells begin to aggregate together using cyclic AMP as a chemo-attractant. 3) In late aggregation, the cells form a mound. 4) The cells form a multicellular slug. In D. discoideum, the slug migrates to a new location, forms a stalk, and then completes development. In D. purpureum, the slug forms a stalk as it migrates to a new location and then completes development. 5) The final fruiting body stage where some of the cells have become sterile to form a stalk and hold up the reproductive spore body.