Polarization and migration in the zebrafish posterior lateral line system
Simulation kymographs for Wnt and FGF signalling. Initially, we assumed a gradient W1(x) = bx + 0.03 in the uncoupled Wnt steady state parameter, with b = 0.01. Time increases downwards; position across the PLLP is horizontal, with leading edge on the right. (a) Wnt ligand, W(x, t), (b) Wnt receptors, WR(x, t), (c) bound Wnt receptors, WB(x, t), (d) FGF ligand, F(x, t), (e) FGF receptors, FR(x, t), and (f) bound FGF receptors, FB(x, t). Signalling domains form after a few minutes, with a sharp boundary between zones. Bound ligand concentrations are calculated using Eq (3). Parameters are as in Table A in Supporting Information S6 Text. Parameter Estimation and Values. Initial conditions: W(x, 0) = 0.01, F(x, 0) = 0.005, WR(x, 0) = 0.1, FR(x, 0) = 0.01.