PT - JOURNAL ARTICLE AU - Julio Belmonte AU - Maria Leptin AU - Nédélec François TI - A theory that predicts behaviors of disordered cytoskeletal networks AID - 10.1101/138537 DP - 2017 Jan 01 TA - bioRxiv PG - 138537 4099 - http://biorxiv.org/content/early/2017/05/16/138537.short 4100 - http://biorxiv.org/content/early/2017/05/16/138537.full AB - Morphogenesis in animal tissues is largely driven by tensions of actomyosin networks, generated by an active contractile process that can be reconstituted in vitro. Although the network components and their properties are known, the requirements for contractility are still poorly understood. Here, we describe a theory that predicts whether an isotropic network will contract, expand, or conserve its dimensions. This analytical theory correctly predicts the behavior of simulated networks consisting of filaments with varying combinations of connectors, and reveals conditions under which networks of rigid filaments are either contractile or expansile. Our results suggest that pulsatility is an intrinsic behavior of contractile networks if the filaments are not stable but turn over. The theory offers a unifying framework to think about mechanisms of contractions or expansion. It provides a foundation for the study of a broad range of processes involving cytoskeletal networks, and a basis for designing synthetic networks.