Cell-cell signaling and adhesion in phagocytosis and early development of Dictyostelium

Cell-cell signaling and adhesion regulate transition from the unicellular t o the multicellular stage of development in the cellular slime mold Dicryos telium. Essential gene networks involved in these processes have been ident ified and their interplay dissected. Heterotrimeric G protein-linked signal transduction plays a key role in regulating expression of genes mediating chemotaxis or cell adhesion, as well as coordinating actin-based cell motil ity during phagocytosis and chemotaxis. Two classes of cell adhesion molecu les, one cadherin-like and the second belonging to the IgG superfamily, con tribute to the strength of adhesion in Dictyostelium aggregates. The develo pmental role of genes involved in motility and adhesion, and their degree o f redundancy, have been re-assessed by using novel developmental assay cond itions which are closer to development in nature.