Periodic Cell Communication in Dictyostelium discoideum

The evolution of multicellular organisms required communication between cells. The cellular slime mould Dictyostelium discoideum is well suited for studies of intercellular communication at the transition from unicellular to multicellular organisms. Cells of D. discoideum feed and multiply as solitary amoebae. Upon depletion of the food source, growth phase cells differentiate into aggregative ones that assemble to form multicellular structures. These structures develop into fruiting bodies composed of stalk cells and spores. During differentiation to the aggregative state, cells acquire the capacity to communicate via chemical signals. In a population of cells, presumably those cells that first emit the signals become aggregation centers. Cells in the vicinity respond chemo-tactically to signal substances and they amplify and relay the signals. The centers emit the signals in a periodic manner, and aggregation occurs in steps of periodic movement [1–3].