We are pleased to announce our first PoL Research Seminar this year with a talk by Kinneret Keren from the Physics Department of Technion – Israel Institute of Technology.
Physics of Hydra Morphogenesis – Abstract
We focus on the mechanical aspects of animal 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 an entire animal from small tissue pieces, providing a flexible platform to explore how mechanical forces and feedback contribute to the formation and stabilization of the body plan during morphogenesis. I will present our results showing that the nematic order of the supracellular actomyosin fibers in regenerating Hydra defines a coarse-grained field, whose dynamics provide an effective description of the morphogenesis process. Topological defects in the nematic order, which emerge early in the regeneration process, identify the sites where morphological features develop in the regenerating animal. We show that contractile activity in the actomyosin fibers leads to extensive, transient tissue deformations at these defect sites. Based on these results, we suggest a mechanochemical feedback loop in which mechanical strain focusing at defect sites provides local positional cues that help guide the formation of a new head organizer in the regenerating animal.
The talk can also be attended over Zoom.