Hydra morphogenesis as phase transition dynamics

- We utilize whole-body Hydra regeneration from a small tissue segment to develop a physics framework for animal morphogenesis. Introducing experimental controls over this process, an external electric field and a drug that blocks gap junctions, allows us to characterize the essential step in the morphological transition -from a spherical shape to an elongated spheroid. We find that spatial fluctuations of the Ca2+ distribution in the Hydra's tissue drive this transition and construct a field-theoretic model that explains the morphological transition as a first-order-like phase transition resulting from the coupling of the Ca2+ field and the tissue's local curvature. Various predictions of this model are verified experimentally.

Automated summary

This study develops a physics framework for animal morphogenesis based on whole-body Hydra regeneration. By introducing experimental controls, including an external electric field and a drug that blocks gap junctions, the researchers characterize the essential step in the morphological transition from a spherical shape to an elongated spheroid. They find that spatial fluctuations of the Ca2+ distribution in the Hydra's tissue drive this transition and propose a field-theoretic model to explain it.