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bioRxiv · 10.1101/2021.02.05.429954

β-Catenin and canonical Wnts control two separate pattern formation systems in Hydra: Insights from mathematical modelling

Mercker, M.·Lengfeld, T.·Höger, S.·Tursch, A.·Lommel, M.·Holstein, T. W.·Marciniak-Czochra, A.
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Abstract

The formation of body axes and apical termini is crucial for animal development. In Hydra, nuclear {beta}-catenin and Wnt3 play key roles and were previously thought to be part of a single mechanism for axis and head formation. This study challenges this view by combining mathematical modeling with experimental data. We show that {beta}-catenin and Wnt3 patterning in Hydra operate at two different scales, requiring distinct inhibitory mechanisms. {beta}-catenin, possibly interacting with other Wnts, co-ordinates axis formation, whereas Wnt3 is involved in small-scale head patterning. A double-loop reaction-diffusion model was developed, demonstrating the ability to describe patterns with divergent shapes, which single-loop models could not achieve. The previously proposed threshold mechanism for Wnt3 expression based on {beta}-catenin prepatterns could not explain the data. Our results suggest a more complex patterning mechanism in other animals, where axis and head formation may not be controlled by a single process.

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Mercker, M., Lengfeld, T., Höger, S., Tursch, A., Lommel, M., Holstein, T. W., Marciniak-Czochra, A.. 2021-02-07. β-Catenin and canonical Wnts control two separate pattern formation systems in Hydra: Insights from mathematical modelling. https://doi.org/10.1101/2021.02.05.429954

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