Impact of filament dynamics on actomyosin flows

While myosin driven activity in actin networks has proven to be a good model system for studying active matter, actin filaments have internal dynamics that are less well understood. In cells, filaments continuously depolymerize on one end while repolymerizing on the other, an active process that can both relax stresses by depolymerizing stretched filaments and create forces by driving actin into the cell membrane. Here, we study how this activity affects the ability of actin networks to store energy and propagate forces. Using a minimal system we previously developed, we are able to add actin dynamics to systems composed of both short filaments, which form a liquid crystal, and long ones, which form a contractile-network when in the presence of myosin motors. Preliminary results suggest that filament dynamics cause actomyosin networks to contract uniaxially, implying that dynamic filaments contract through sliding, in contrast to stable filaments which contract through buckling. Simultaneously, dynamics redistribute actin allowing the network to maintain long-lasting contractile flows.