Research Article

Self-Organization of Motor-Propelled Cytoskeletal Filaments at Topographically Defined Borders

Figure 5

Monte-Carlo simulations of actin filament paths for the experimental situation in Figures 4(b) and 4(c) with 8 motile filaments (10 filaments in the simulations for practical reasons), a velocity of 3 μm/s, and a total integration time of 60 s. (a) Simulated filament paths (blue) with starting points (green) and end-points (red). The motility supporting area is indicated by weak red (circular part) and green (to the far left; polynomial part) lines. For symmetry reasons, the simulations were limited to a half-circular shape which simplified the algorithm. Thus, filament paths are reflected in the top border of the simulated area, corresponding to their motility with unchanged sliding direction past this border. (b) The radial distribution of filament positions accumulated during the entire simulation period. Here, 0 corresponds to the centre of the circular motility supporting zone, and 100% corresponds to the border with the LOR/PMMA-area. (c) Simulation of sliding along 200 nm wide track similar to that in Figure 1. Simulation limited to lower half of the track with reflection of filament paths in track midline (top of diagram). Thus, simulated filament paths at bottom of figure correspond either to motility at the lower or top edge of the track. (d) Simulation of sliding along 700 nm wide track (delimited by upper and lower full lines) as in Figure 4(d). Simulation only for lower half of track with reflection in midline (dashed line) as in Figure 5(c). (e) Simulation as in Figure 5(d) but track width increased to 1.2 μm.
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