We present a three-dimensional hybrid cellular automata. (CA)/partial
differential equation (PDE) model that allows for the study of morphog
enesis in simple cellular systems. We apply the model to the cellular
slime mold Dictyostelium discoideum ''from single cells to crawling sl
ug''. Using simple local interactions we can achieve the basic morphog
enesis with only three processes: production of and chemotaxis to cAMP
and cellular adhesion. The interplay of these processes causes the am
oebae to spatially self-organize leading to the complex behaviour of s
tream and mound formation, cell sorting and slug migration all without
any change of parameters during the complete morphogenetic process. (
C) 1997 Academic Press Limited.