PT  - JOURNAL ARTICLE
AU  - Mercker, Moritz
AU  - Tursch, Anja
AU  - Veerman, Frits
AU  - Kazarnikov, Alexey
AU  - Höger, Stefanie
AU  - Lengfeld, Tobias
AU  - Özbek, Suat
AU  - Holstein, Thomas W
AU  - Marciniak-Czochra, Anna
TI  - Two separate but interconnected pattern formation systems are required to control body-axis and head-organiser formation in <em>Hydra</em>
AID  - 10.1101/2021.02.05.429954
DP  - 2024 Jan 01
TA  - bioRxiv
PG  - 2021.02.05.429954
4099  - http://biorxiv.org/content/early/2024/03/28/2021.02.05.429954.short
4100  - http://biorxiv.org/content/early/2024/03/28/2021.02.05.429954.full
AB  - Formation of the body axes and the apical termini are fundamental steps during animal development. Here, nuclear β-catenin and canonical Wnt3 have been identified as major players in Hydra, which belongs to the early diverging phylum of cnidaria. However, both molecules have previously been assumed to be part of the same pattern formation system. In this study, we revised this view by combining mathematical modeling with previous and new experimental data demonstrating that they contribute to two largely independent de novo pattern formation systems in Hydra. Notably, β-catenin (possibly in interplay with other Wnts) appeared to act at the whole-body scale contributing to axis formation, whereas Wnt3 was involved in a downstream pathway driving small-scale patterning of the head. These results also suggest that these mechanisms may be more complex in other animals, in which axis and head formation have previously been attributed to a single pattern formation mechanism.Competing Interest StatementThe authors have declared no competing interest.