Wnt-Dependent Epithelial Transitions Drive Pharyngeal Pouch Formation
Wnt-Dependent Epithelial Transitions Drive Pharyngeal Pouch Formation
复制标题
DOI：
10.1016/j.devcel.2012.12.003
复制
发表时间：
2013-02-11
影响因子：
11.8
通讯作者：
Crump, J. Gage
中科院分区：
文献类型：
--
作者：
Choe, Chong Pyo;Collazo, Andres;Crump, J. Gage
咽囊是由前肠内胚层出芽形成的，对于脊椎动物面部的分割至关重要。迄今为止，这种出芽的细胞机制和节段性仍然难以捉摸。在这里，我们发现，Wnt11r和Wnt4a的头部中胚层和外胚层，分别在斑马鱼的囊节段形成发挥不同的作用。延时显微镜，结合突变体和组织特异性转基因实验，揭示了Wnt信号在内胚层上皮转变的两个阶段的要求。最初，Wnt11r和Rac 1使内胚层上皮不稳定，以促进袋形成细胞的侧向运动。接下来，Wnt4a和Cdc42信号传导通过Alcama免疫球蛋白结构域蛋白的连接定位诱导成熟囊袋细胞重排成双层，其功能是重新稳定粘附连接。我们提出，这种动态控制上皮形态的Wnt信号可能是一个共同的主题，从内胚层器官原基的萌芽。
The pharyngeal pouches, which form by budding of the foregut endoderm, are essential for segmentation of the vertebrate face. To date, the cellular mechanism and segmental nature of such budding have remained elusive. Here, we find that Wnt11r and Wnt4a from the head mesoderm and ectoderm, respectively, play distinct roles in the segmental formation of pouches in zebrafish. Time-lapse microscopy, combined with mutant and tissue-specific transgenic experiments, reveal requirements of Wnt signaling in two phases of endodermal epithelial transitions. Initially, Wnt11r and Rac1 destabilize the endodermal epithelium to promote the lateral movement of pouch-forming cells. Next, Wnt4a and Cdc42 signaling induce the rearrangement of maturing pouch cells into bilayers through junctional localization of the Alcama immunoglobulin-domain protein, which functions to restabilize adherens junctions. We propose that this dynamic control of epithelial morphology by Wnt signaling may be a common theme for the budding of organ anlagen from the endoderm.