Figure 10.

Snapshots for simulation results for different parameters. (A) Simulation for case of no cytomatrix assembly at the cortex (assembly occurs only at the contact boundary). Network assembly at the cortex is required for translation toward the substratum. (B) Simulation showing the effect of reduced adhesion. Reducing adhesion allows retrograde flow at the substratum; ultimately the flow speed matches the speed of network assembly, yielding steady-state cell and nucleus shapes. The nucleus shape changes cease when spreading stops. (C) Simulation with no contractile stress within the network $\left({\sigma }_c=0\right)$. Nuclear flattening is predicted to arise from flow alone without requiring actomyosin contractile stresses in the network, consistent with the observation of flattening under myosin inhibition. (D) Simulation of a cell with no resistance to nuclear lamina area expansion. Without area stiffness, the nucleus continues to flatten at a nearly constant volume. (E) Plot of nuclear height (blue line), width (black line), and cell spreading area (green line) versus time for the cases show in (A)–(D). (F) Plot of apparent nuclear surface area (blue line) and volume (green line) for cases (A)–(E). To see this figure in color, go online.