Figure 3.

Coupling to the cytoskeleton acts to entrain channels of white pixels over filaments, leaving pools of black pixels within cytoskeletal corrals. (A) The time-averaged density of white pixels is correlated with the position of the cytoskeleton at 37°C (1.05 T_C). In the absence of cytoskeletal coupling (inset) the average density is trivially uniform. (B) The spatial autocorrelation function, G(r), is not significantly altered by the presence of cytoskeletal coupling (compare the dashed blue and dot-dashed red lines). In each case, G(r) decays over a correlation length of ∼20 nm. In addition, the spatial cross-correlation function between white pixels and pinning sites (solid red line) indicates that long-range correlations extend over roughly one correlation length. (C) In a hypothetical membrane that is not tuned to the proximity of a critical point at 37°C, but instead is tuned with a critical temperature of −120°C, the channels gathered by the cytoskeleton are much thinner and their contrast is diminished. This is the expected behavior for a well-mixed membrane that is not near a critical point. (D) All of the corresponding correlation functions decay over a much shorter distance. (Color online.)