Wnt/β-Catenin and noncanonical Wnt signaling interact in tissue evagination in the simple eumetazoan Hydra
Wnt/β-Catenin and noncanonical Wnt signaling interact in tissue evagination in the simple eumetazoan Hydra
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DOI：
10.1073/pnas.0812847106
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发表时间：
2009-03-17
影响因子：
11.1
通讯作者：
Hobmayer, Bert
中科院分区：
文献类型：
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作者：
Philipp, Isabelle;Aufschnaiter, Roland;Hobmayer, Bert
2D细胞膜的内、外翻是动物发育过程中的主要形态发生过程。它们是由与细胞形状变化相关的极化细胞的定向运动和插入引起的。在几个双边模式生物上的工作强调了非规范的Wnt信号在细胞极化和运动中的作用。然而，在祖先的双侧前动物中，负责产生组织和身体形状的分子过程尚不清楚。我们发现，非典型的Wnt信号在海蛇的芽和触须外露和再生期间的大量组织运动中起作用。Wnt5、wnt8、Frizzled2(Fz2)和蓬乱表达的细胞团定义了芽和触须外翻的起始位置；wnt8、fz2和disheveled在这些上皮细胞中保持上调表达，在整个外翻过程中经历细胞形状的变化。在wnt和dsh表达的下游，JNK活性是外吐过程所必需的。Wnt5、wnt8、fz2和乱蓬蓬的多个异位表达中心以及随后异位触须的外展是通过激活Wnt/β-catenin信号在整个体柱中诱导的。我们的结果表明，通过规范和非规范Wnt通路的协调作用，轴向模式和组织形态发生的整合对于Eumetazoan身体计划的进化至关重要。
In and evaginations of 2D cell sheets are major shape generating processes in animal development. They result from directed movement and intercalation of polarized cells associated with cell shape changes. Work on several bilaterian model organisms has emphasized the role of noncanonical Wnt signaling in cell polarization and movement. However, the molecular processes responsible for generating tissue and body shape in ancestral, prebilaterian animals are unknown. We show that noncanonical Wnt signaling acts in mass tissue movements during bud and tentacle evagination and regeneration in the cnidarian polyp Hydra. The wnt5, wnt8, frizzled2 (fz2), and dishevelled-expressing cell clusters define the positions, where bud and tentacle evaginations are initiated; wnt8, fz2, and dishevelled remain up-regulated in those epithelial cells, undergoing cell shape changes during the entire evagination process. Downstream of wnt and dsh expression, JNK activity is required for the evagination process. Multiple ectopic wnt5, wnt8, fz2, and dishevelled-expressing centers and the subsequent evagination of ectopic tentacles are induced throughout the body column by activation of Wnt/beta-Catenin signaling. Our results indicate that integration of axial patterning and tissue morphogenesis by the coordinated action of canonical and noncanonical Wnt pathways was crucial for the evolution of eumetazoan body plans.