Dynamic swarms regulate the morphology and distribution of soft membrane domains

Abstract

We study the dynamic structure of lipid domain inclusions embedded within a phase-separated reconstituted lipid bilayer in contact with a swarming flow of gliding filamentous actin. Passive circular domains transition into highly-deformed morphologies that continuously elongate, rotate, and pinch off into smaller fragments, leading to a dynamic steady state with approximately 23x speed up in the relaxation of the intermediate scattering function compared to passive membrane domains driven by purely thermal forces. To corroborate experimental results, we develop a phase-field model of the lipid domains with two-way coupling to the Toner-Tu equations. We report phase domains that become entrained in the chaotic eddy patterns, with oscillating waves of domains that correlate with the dominant wavelengths of the Toner-Tu flow fields.