Fig. 3: Active gel model predicts bistability of cell migration.
From: Optogenetic control of migration of contractile cells predicted by an active gel model
a Cell velocities V and the length differences from the sessile state, \(\Delta L=L-{\hat{L}}_{+}\), for the obtained solution branches as a function of Péclet number Pe for different (supercritical) attractive energies eA. The bifurcation points are marked with circles. Stable (unstable) solutions are shown as solid (dashed). b State diagram for eA = 0.63 and for \({{{{{{{{\mathcal{L}}}}}}}}}^{2}{{{{{{{\mathcal{A}}}}}}}}=1.25/77\) fixed (containing parameters, which cannot be changed by the cell, cf. text). Depending on adhesion strength \({{{{{{{\mathcal{A}}}}}}}}\) and contractility \({{{{{{{\mathcal{P}}}}}}}}\), one finds a sessile, bistable or motile regime. Parameter values estimated from experiments are marked with a circle and used in (c). The solid/dot-dashed curves correspond to the loci of the pitchfork/saddle node bifurcation. c Normalized motor concentration profiles for experimental parameters (and V ≥ 0) in the bistable regime for the stable sessile, the unstable motile and stable motile solutions, shown as solid red curves. The flow velocities are shown as dashed lines. For the stable motile steady state the resulting diffusion coefficient \({{{{{{{\mathcal{D}}}}}}}}(c(u))\) inside the cell is shown as solid black curve.
