Cytoskeletal networks, which are essentially motor-filament assemblies, playa major role in many developmental processes involving structural remodelingand shape changes. These are achieved by nonequilibrium self-organizationprocesses that generate functional patterns and drive intracellular transport.We construct a minimal physical model that incorporates the coupling betweennonlinear elastic responses of individual filaments and force-dependent motoraction. By performing stochastic simulations we show that the interplay ofmotor processes, described as driving anti-correlated motion of the networkvertices, and the network connectivity, which determines the percolationcharacter of the structure, can indeed capture the dynamical and structuralcooperativity which gives rise to diverse patterns observed experimentally. Thebuckling instability of individual filaments is found to play a key role inlocalizing collapse events due to local force imbalance. Motor-drivenbuckling-induced node aggregation provides a dynamic mechanism that stabilizesthe two dimensional patterns below the apparent static percolation limit.Coordinated motor action is also shown to suppress random thermal noise onlarge time scales, the two dimensional configuration that the system startswith thus remaining planar during the structural development. By carrying outsimilar simulations on a three dimensional anchored network, we find that themyosin-driven isotropic contraction of a well-connected actin network, whencombined with mechanical anchoring that confers directionality to thecollective motion, may represent a novel mechanism of intracellular transport,as revealed by chromosome translocation in the starfish oocyte.
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