Hydra Regeneration: Closing the Loop with Mechanical Processes in Morphogenesis.

The convergence of morphogenesis into viable organisms under variable conditions suggests closed-loop dynamics involving multiscale functional feedback. We develop the idea that morphogenesis is based on synergy between mechanical and bio-signaling processes, spanning all levels of organization: molecular, cellular, tissue, up to the whole organism. This synergy provides feedback within and between all levels of organization, to close the loop between the dynamics of the morphogenesis process and its robust functional outcome. Hydra offer a powerful platform to explore this direction, thanks to their simple body plan, extraordinary regeneration capabilities, and the accessibility and flexibility of their tissues. Our recent experiments show that structural inheritance of the actomyosin organization directs body-axis formation during Hydra regeneration. Morphogenesis is then stabilized through dynamic cytoskeletal reorganization induced by the inherited structure. The observed cytoskeletal stability and reorganization capabilities suggest that mechanical feedback integrates with biochemical processes to establish viable patterns and ensure canalization.