A HYDRODYNAMIC MODEL FOR DICTYOSTELIUM-DISCOIDEUM MOUND FORMATION

Coordinated cell movement is the major mechanism controlling the multi cellular morphogenesis of the slime mould Dictyostelium discoideum. Si ngle cells aggregate chemotactically in response to propagating waves of cAMP to form a multicellular organism. Here we present a model to d escribe the formation of these multicellular aggregates. Cell movement is modelled as the flow of a compressible fluid controlled by cAMP-in duced chemotactic forces, frictional and adhesion forces and internal pressure. The model can simulate the whole early process of developmen t from isolated single cells, formation of bifurcating aggregation str eams and formation of a three-dimensional aggregate with a single set of parameters. Direct comparison of simulations with experimental imag es of successive aggregation stages show a striking agreement. The mod el can also mimic alternative modes of morphogenesis frequently observ ed after disturbance of cAMP signalling or cell motility by chemicals or mutations. (C) 1997 Academic Press Limited.