1-D numerical simulations of Model B. Simulations demonstrate that the Pax6/Fst/Tgfb2 network of Model B could spontaneously polarise the optic vesicle into Pax6+ and Pax6- ‘poles’ if Fst:Tgfb2 hetero-tetramer diffusion exceeds that of Fst monomers. Pax6 was initially distributed throughout a circular tissue, but with small local fluctuations. Simulations were performed using different relative diffusion rates for Fst monomers (x-axis) and Tgfb2 dimers (y-axis), while Fst:Tgfb2 hetero-tetramer diffusion rate was held constant. Simulations are shown three times; first with both Pax6 (red) and activated Tgfb receptor (i.e. Tgfb2:Tgfbr complex; cyan) concentrations together; second with just activated receptor concentrations; third with just Pax6 concentrations.