Shh and Wnt signaling pathways converge to control Gli gene activation in avian somites.
Shh and Wnt signaling pathways converge to control Gli gene activation in avian somites.
复制标题
DOI：
--
复制
发表时间：
2000-05
期刊：
影响因子：
4.6
通讯作者：
A. Borycki;A. Brown;C. Emerson
中科院分区：
文献类型：
--
作者：
A. Borycki;A. Brown;C. Emerson
在鹌鹑胚胎体节形成过程中Gli基因的调控进行了研究。Gli基因是一个家族，编码三个相关的锌指转录因子Gli 1、Gli 2和Gli 3，它们是应答细胞中Shh信号的效应子。克隆了鹌鹑Gli 3 cDNA，并将其表达与Gli 1和Gli 2进行比较。这些研究表明，Gli 1，Gli 2和Gli 3在体节形成时被共激活，从而提供了一种调节体节中Shh信号起始的机制。胚胎手术和近轴中胚层外植体实验表明，每个Gli基因是由不同的信号传导机制。Gli 1响应于脊索产生的Shh而被激活，这也控制了Gli 2和Gli 3在通过来自表面外胚层和神经管的Wnt信号激活后的背侧化。这种表面外胚层/神经管Wnt信号在Gli 2和Gli 3调节中具有负和正功能：这些信号在体节形成之前抑制节段板中胚层中的Gli 3，然后促进体节形成和Gli 2和Gli 3的体节特异性激活。这些研究，因此，建立了一个作用Wnt信号在控制Shh信号转导通过调节Gli 2和Gli 3，并提供了一个机制的基础上已知的协同作用的表面外胚层/神经管和脊索信号在体节细胞规格。
The regulation of the Gli genes during somite formation has been investigated in quail embryos. The Gli genes are a family encoding three related zinc finger transcription factors, Gli1, Gli2 and Gli3, which are effectors of Shh signaling in responding cells. A quail Gli3 cDNA has been cloned and its expression compared with Gli1 and Gli2. These studies show that Gli1, Gli2 and Gli3 are co-activated at the time of somite formation, thus providing a mechanism for regulating the initiation of Shh signaling in somites. Embryo surgery and paraxial mesoderm explant experiments show that each of the Gli genes is regulated by distinct signaling mechanisms. Gli1 is activated in response to Shh produced by the notochord, which also controls the dorsalization of Gli2 and Gli3 following their activation by Wnt signaling from the surface ectoderm and neural tube. This surface ectoderm/neural tube Wnt signaling has both negative and positive functions in Gli2 and Gli3 regulation: these signals repress Gli3 in segmental plate mesoderm prior to somite formation and then promote somite formation and the somite-specific activation of Gli2 and Gli3. These studies, therefore, establish a role for Wnt signaling in the control of Shh signal transduction through the regulation of Gli2 and Gli3, and provide a mechanistic basis for the known synergistic actions of surface ectoderm/neural tube and notochord signaling in somite cell specification.