Development of the aboral domain in Nematostella requires β-catenin and the opposing activities of Six3/6 and Frizzled5/8
Development of the aboral domain in Nematostella requires β-catenin and the opposing activities of Six3/6 and Frizzled5/8
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DOI：
10.1242/dev.120931
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发表时间：
2016-05-15
期刊：
影响因子：
4.6
通讯作者：
Rentzsch, Fabian
中科院分区：
文献类型：
--
作者：
Leclere, Lucas;Bause, Markus;Rentzsch, Fabian
在刺胞动物的口极和后极的发育在bilaterians是由典型的Wnt信号调节，而一组转录因子，包括Six 3/6和FoxQ 2，控制aboral发育的刺胞动物和前的身份bilaterians。然而，人们对这两个图案化系统最初是如何设置的，以便沿着主体轴线沿着产生正确的图案化，了解得很少。调查海葵Nematostella vectensis的反口极形成的早期步骤，我们发现，在囊胚期，口腔基因的表达前aboral基因和Nv β-连环蛋白调节口腔和aboral的发展。在口腔半球，Nv β-连环蛋白指定除了口腔最，NvSnailA表达域，其在Nv β-连环蛋白敲低后扩展的所有子域。此外，Nv β-连环蛋白通过促进NvSix 3/6在离口极的表达和抑制Wnt受体NvFrizzled 5/8在口腔极建立离口模式系统。NvFrizzled 5/8的表达因此被限制在背口结构域。在原肠胚阶段，NvSix 3/6和NvFrizzled 5/8都在反口结构域中表达，但它们具有相反的活性，NvSix 3/6维持反口结构域的大小，NvFrizzled 5/8限制反口结构域的大小。在浮游期，NvFrizzled 5/8是需要的图案内的aboral域和调节顶端器官的大小，通过调制以前的特征FGF反馈回路。我们的研究结果表明，保守的作用Six 3/6和Frizzled 5/8在aboral/前部的发展，并揭示了Nv β-连环蛋白的模式的整个口aboral轴的Nematostella的关键功能。
The development of the oral pole in cnidarians and the posterior pole in bilaterians is regulated by canonical Wnt signaling, whereas a set of transcription factors, including Six3/6 and FoxQ2, controls aboral development in cnidarians and anterior identity in bilaterians. However, it is poorly understood how these two patterning systems are initially set up in order to generate correct patterning along the primary body axis. Investigating the early steps of aboral pole formation in the sea anemone Nematostella vectensis, we found that, at blastula stage, oral genes are expressed before aboral genes and that Nv beta-catenin regulates both oral and aboral development. In the oral hemisphere, Nv beta-catenin specifies all subdomains except the oral-most, NvSnailA-expressing domain, which is expanded upon Nv beta-catenin knockdown. In addition, Nv beta-catenin establishes the aboral patterning system by promoting the expression of NvSix3/6 at the aboral pole and suppressing the Wnt receptor NvFrizzled5/8 at the oral pole. NvFrizzled5/8 expression thereby gets restricted to the aboral domain. At gastrula stage, NvSix3/6 and NvFrizzled5/8 are both expressed in the aboral domain, but they have opposing activities, with NvSix3/6 maintaining and NvFrizzled5/8 restricting the size of the aboral domain. At planula stage, NvFrizzled5/8 is required for patterning within the aboral domain and for regulating the size of the apical organ by modulation of a previously characterized FGF feedback loop. Our findings suggest conserved roles for Six3/6 and Frizzled5/8 in aboral/anterior development and reveal key functions for Nv beta-catenin in the patterning of the entire oral-aboral axis of Nematostella.