Figure 7.

Model predictions for the fan-shaped cell. (A) Hypothesized centripetal actin flow field (green arrows) with flow center (cross) near the centroid. (B–D) Snapshots of the simulations with isotropic MT nucleation (B), anisotropic MT nucleation with density of MTs growing toward the round edge being twice the density of MTs growing toward the corner (C), and anisotropic MT nucleation as described in B, but with additional motors at the cell “leading edge” (marked with red dots). Green lines, MTs. Blue circle, CS. Thick gray lines, cell periphery. White crosses, flow center. Bar, 10 μm.