IPLS Seminar - Prof. Kinneret Keren (The Technion Department of Physics)

Abstract: Morphogenesis is one of the most remarkable examples of biological self-organization. Despite substantial progress, we still do not understand the organizational principles underlying the convergence of this process, across scales, to form viable organisms. We focus on the mechanical aspects of morphogenesis using Hydra, a small multicellular fresh-water animal, as a model system. Hydra has a simple body plan and is famous for its ability to regenerate its whole body from small tissue segments. Thanks to its relative simplicity and regeneration capabilities, Hydra provides a flexible platform to explore how mechanical forces and feedback contribute to the formation and stabilization of the body plan during morphogenesis. I will discuss our recent results showing that structural inheritance of the supra-cellular actin fibers directs body-axis formation in regenerating Hydra. I will further describe our efforts to develop a framework relating the dynamics of the nematic organization of these supra-cellular actin fibers to the morphogenesis process. In particular, I will show that topological defects in the nematic order act as organizers of the developing body plan. Finally, I will describe our attempts to directly probe the influence of mechanics on morphogenesis, by applying various external mechanical constraints on regenerating Hydra.