We studied regenerating bilayered tissue toroids dissected from
Hydra vulgaris polyps and relate our macroscopic observations to the dynamics
of force-generating mesoscopic cytoskeletal structures. Tissue fragments
undergo a specific toroid–spheroid folding process leading to complete
regeneration towards a new organism. The time scale of folding is too fast for
biochemical signalling or morphogenetic gradients, which forced us to assume
purely mechanical self-organization. The initial pattern selection dynamics was
studied by embedding toroids into hydro-gels, allowing us to observe the
deformation modes over longer periods of time.We found increasing mechanical
fluctuations which break the toroidal symmetry, and discuss the evolution of their
power spectra for various gel stiffnesses. Our observations are related to singlecell
studies which explain the mechanical feasibility of the folding process. In
addition, we observed switching of cells from a tissue bound to a migrating
state after folding failure as well as in tissue injury. We found a supra-cellularactin ring assembled along the toroid’s inner edge. Its contraction can lead to the
observed folding dynamics as we could confirm by finite element simulations.
This actin ring in the inner cell layer is assembled by myosin-driven length
fluctuations of supra-cellular F-actin bundles (myonemes) in the outer cell layer.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:80301 |
| Date | 02 August 2022 |
| Creators | Krahe, Michael, Wenzel, Iris, Lin, Kao-Nung, Fischer, Julia, Goldmann, Joseph, Kästner, Markus, Fütterer, Claus |
| Publisher | IOP Publishing |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 035004 |
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