Self-Regulation of Minimal Contractile Active Systems

Minimal reconstituted systems of cytoskeletal filaments and molecular motors have proven a valuable platform for understanding spontaneous self-organization in active matter systems. Recent experimental results have highlighted the diverse set of behaviors systems of reconstituted cytoskeleton networks and motors can take on, and their ability to create self-organized structures that can regulate their behavior in the absence of biochemical signaling. However, even in minimal cytoskeletal systems, teasing out mechanisms for phenomena from experimental results remains challenging due to competing effects introduced by integrating multiple interacting cytoskeletal components and due to feedback mechanisms by which the macro-scale dynamics of these systems influence the agent-scale behavior. Here, we perform fluorescence microscopy assays on a minimal system of stabilized filaments and molecular motors. We show that the most minimal possible cytoskeletal active system is sufficient to generate self-regulating contractile structures, and map the dependence of the behavior of the system given different concentrations of components of the system. Our results represent an important step forward in understanding the physical origins of spatiotemporal self-regulation in active matter systems, as well as informing principles for minimal requirements for autonomous spatiotemporal control of bio-inspired active materials.