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BP: Fachverband Biologische Physik
BP 32: Tissue Mechanics II
BP 32.7: Vortrag
Donnerstag, 21. März 2024, 16:45–17:00, H 2032
A mechano-chemical model of Hydra regeneration — •Suganthan Senthilkumar1, Yonit Maroudas-Sacks2, Kinneret Keren2, and Marko Popović1 — 1Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden — 2Technion University, Haifa, 3200003, Israel
Hydra is a freshwater animal with extraordinary regeneration properties making it an excellent model organism to study morphogenesis. It has a simple body plan, with a double layered epithelium enclosing a fluid-filled lumen. Hydra epithelia contain long actin muscle fibres that are highly organized with an aster point defect positioned at the head. Starting from an excised tissue fragment Hydra can fully regenerate, however, it is unclear how the fibre pattern self organizes. The regeneration of the fibre pattern is inhibited by perturbing either tissue strain or production of Wnt, which is a morphogen relevant for head regeneration. We propose a mechano-chemical feedback between tissue mechanics, nematic fibre pattern and morphogen dynamics, as a mechanism of Hydra regeneration. For this we have developed a vertex model of curved epithelia that incorporates the feedback mechanism. In the model, each cell contains a nematic, representing the orientation of actin fibres, that generate stress upon activation, and a morphogen concentration. We implement the mechano-chemical feedback such that the morphogen production depends on cellular strain, with morphogen gradients guiding nematic orientation, which in turn focusses the tissue strain. We find that this mechanism can robustly reproduce experimentally observed dynamics of Hydra tissue and nematic fibres.
Keywords: Morphogenesis; Elasticity; Nematic patterning