Department of Embryology, Faculty of Biology, Lomonosov Moscow State University, Leninskiye gory 1/12, Moscow, 119234, Russia; Department for Molecular Evolution and Development, Centre of Organismal Systems Biology, University of Vienna, Althanstraße 14, Vienna, A-1090, Austria.
Department of Embryology, Faculty of Biology, Lomonosov Moscow State University, Leninskiye gory 1/12, Moscow, 119234, Russia.
Dev Biol. 2019 Dec 15;456(2):145-153. doi: 10.1016/j.ydbio.2019.08.019. Epub 2019 Aug 29.
At the polyp stage, most hydrozoan cnidarians form highly elaborate colonies with a variety of branching patterns, which makes them excellent models for studying the evolutionary mechanisms of body plan diversification. At the same time, molecular mechanisms underlying the robust patterning of the architecturally complex hydrozoan colonies remain unexplored. Using non-model hydrozoan Dynamena pumila we showed that the key components of the Wnt/β-catenin (cWnt) pathway (β-catenin, TCF) and the cWnt-responsive gene, brachyury 2, are involved in specification and patterning of the developing colony shoots. Strikingly, pharmacological modulation of the cWnt pathway leads to radical modification of the monopodially branching colony of Dynamena which acquire branching patterns typical for colonies of other hydrozoan species. Our results suggest that modulation of the cWnt signaling is the driving force promoting the evolution of the vast variety of the body plans in hydrozoan colonies and offer an intriguing possibility that the involvement of the cWnt pathway in the regulation of branching morphogenesis might represent an ancestral feature predating the cnidarian-bilaterian split.
在息肉阶段，大多数水螅水母形成具有各种分支模式的高度精致的群体，这使它们成为研究身体计划多样化的进化机制的优秀模型。同时，架构复杂的水螅水母群体的强大模式形成的分子机制仍未被探索。使用非模式水螅水母 Dynamena pumila，我们表明 Wnt/β-catenin (cWnt) 途径的关键成分（β-catenin、TCF）和 cWnt 反应基因 brachyury 2 参与了发育中的群体芽的指定和模式形成。引人注目的是，cWnt 途径的药理学调节导致 Dynamena 的单枝状分支群体发生根本性改变，获得其他水螅水母物种群体特有的分支模式。我们的结果表明，cWnt 信号的调节是推动水螅水母群体中大量身体计划进化的驱动力，并提供了一个有趣的可能性，即 cWnt 途径参与分支形态发生的调节可能代表了在刺胞动物-两侧对称动物分裂之前的祖先特征。
