Self-organization phenomena resulting from cell-cell contact

Self-organization phenomena in an ensemble of cells in contact is considered. By a simple and general argument it is shown that in order to have pattern formation or spatio-temporal organization in these systems it is not necessary that chemicals move throughout the field. The influence of one cell on its neighbour can be transmitted by surface contact interactions in which molecules in the surface of one cell influence the rates of reactions in neighbouring cells without the actual passage of molecules from one cell to the other. It is shown that these systems present all the self-organizing properties seen in reaction diffusion systems. The possible biological applications and the role of first bifurcating solution out of the homogeneous state to provide “positional information” in morphogenesis is discussed.