A Hydrodynamic model forDictyostelium discoideumMound Formation

Co-ordinated cell movement is the major mechanism controlling the multicellular morphogenesis of the slime mouldDictyostelium discoideum. Single cells aggregate chemotactically in response to propagating waves of cAMP to form a multicellular organism. Here we present a model to describe the formation of these multicellular aggregates. Cell movement is modelled as the flow of a compressible fluid controlled by cAMP-induce chemotactic forces, frictional and adhesion forces and internal pressure. The model can stimulate the whole early process of development from isolated single cells, formation of bifurcating aggregation streams and formation of a three-dimensional aggregate with a single set of parameters. Direct comparison of simulations with experimental images of successive aggregation stages show a striking agreement. The model can also mimic alternative modes of morphogenesis frequently observed after disturbance of cAMP signalling or cell motility by chemicals or mutations.