Computer simulation of biological pattern generation by purely local interactions: Lobed and smooth boundaries

A model of biological pattern generation by local interactions between cells at the boundary has been tested by computer simulation. A perfect circle or a smooth straight boundary have been generated by a negative feedback between the position of a cell relative to the smooth boundary and its movement, which gives a stable smooth boundary. Regular lobes are generated by having unstable positive feedback relations when the boundary is smooth, and two stable positions, when the boundary is either convex or concave. The size of the lobes increases and their number decreases when the rigidity of the boundary increases. The biological implication of the model is that it seems possible to have a large scale pattern determined by purely short range local interactions between cells.