Figure 5.

Mobility of both actin and microtubules in composites exhibits a nonmonotonic dependence on tubulin fraction. (A–C) 2 × 2 images show binary skeletonization of a single frame (top row) and temporal color maps (bottom row) of movies for (A) ϕ_T = 0, (B) ϕ_T = 1, and (C) ϕ_T = 0.5 networks. Full 512 × 512 images (left) as well as zoomed-in images (right, corresponding to box in left-hand images) are shown. The different colors in temporal color maps correspond to different times during each 180 s movie. Colors go from red at 0 to magenta at 180 s, as shown in the scale bar to the right of each map. (D) The standard deviation of intensity values, σ_I, over all pixels and all frames of each time series, normalized by the corresponding mean, <I>, versus tubulin fraction ϕ_T, is shown. σ_I/<I> is calculated separately for actin and microtubule channels to determine the mobility of each filament in composites. Error bars are the standard error from averaging over 512 × 512 pixels in 3–5 images for each ϕ_T. As shown, the mobility of both actin (circles) and microtubules (squares) increases as ϕ_T increases to 0.5, followed by a subsequent drop. Color coding represents the different ϕ_T values, as in Figs 2, 3, and 4. To see this figure in color, go online.