Figure 1

The life cycle of Dictyostelium discoideum. (A) Most of its life exists in its growth phase, as a haploid social amoeba preying upon bacteria in the soil and dividing by mitosis. Once the food source is depleted cells enter into a 24 h multicellular developmental program. During this transition, amoebae aggregate towards secreted cAMP by chemotaxis in the thousands to form a tight mound and then enter a stage where cells begin to differentiate. Cells within the mound remain motile and are directed to differentiate, by secreted morphogens, into either prestalk or prespore cells, culminating to form a fruiting body comprised of a multicellular stalk that supports a ball of encapsulated dormant spores. (B) Scanning electron microscopy showing the various structures formed during development. Permissions: CC Creative Commons Attribution - Share Alike 3.0, David Brown & Joan E. Strassmann. SEM courtesy of MJ Grimson & RL Blanton, Biological Sciences Electron Microscopy, Texas Tech University.