Simulating muti-component and supra-cellular actomyosin systems with CytoSim

The actin cytoskeleton is composed of a collection of protein complexes that interact with actin filaments to drive diverse cellular processes such as cell migration and division, as well as tissue-level processes in which neighboring cells form a supracellular network that enables multicellular events such as convergent-extension and gastrulation. To simulate these processes and study them in silico, cytoskeletal models must move beyond “bare-bones” systems made of only filaments and motors, and incorporate the rich set of actin-binding proteins—including crosslinkers, membrane anchors, nucleators, severing proteins, and others. In this talk, I will review how different groups have simulated these complex systems, demonstrate how this can be done using the CytoSim software, and illustrate these approaches with several applications. I will also discuss how these methods can be extended to simulate supracellular networks, in which multiple independent but interacting cytoskeletal systems coexist, and show how this was accomplished to model the contractile system of ventral mesodermal cells during Drosophila gastrulation.