Speaker
Description
The freshwater polyp Hydra is a classical model organism for studying body axis formation due to its remarkable regenerative capacity. In regenerating tissue spheroids, mechanical cues arising from tissue deformation interact with biochemical signaling pathways and influence pattern formation.
In this talk I will propose a mechanochemical model for body axis formation in regenerating Hydra tissue spheroids that couples morphogen dynamics with tissue mechanics through a positive feedback loop: tissue stretching enhances morphogen production, while morphogen concentration modulates tissue elasticity. This coupling provides a mechanochemical realization of the local activation–long-range inhibition principle.
Within a reduced one-dimensional framework, I will perform a rigorous analytical study of pattern formation. I will prove the existence of stable non-constant steady states and show that all multimodal steady states are linearly unstable, implying that only unimodal patterns persist as stable solutions.
Bifurcation analysis reveals both subcritical and supercritical pitchfork bifurcations, with fold bifurcations generating bistable regimes. The results demonstrate that mechanochemical feedback alone can robustly generate single-peaked patterns without requiring a second diffusible inhibitor, providing a minimal and mechanically grounded mechanism for axis selection in regenerating tissues.
