Abstract：
Development of the central nervous system in amphibians has called attention from scientists for over a century. Interested in the matter of embryonic inductions, Hans Spemann and Hilde Mangold found out that the dorsal blastopore lip of the salamander\'s embryo has organizer properties. Such an ectopic graft could induce structures in the host embryo, including a neural tube overlying the notochord of a perfect secondary body axis. A couple of decades later, the frog Xenopus laevis emerged as an excellent embryological experimental model and seminal concepts involving embryonic inductions began to be revealed. The so-called primary induction is, in fact, a composition of signaling and inductive events that are triggered as soon as fertilization takes place. In this regard, since early 1990s an intricate network of signaling pathways has been built. The Wnt pathway, which began to be uncovered in cancer biology studies, is crucial during the establishment of two signaling centers in Xenopus embryogenesis: Nieuwkoop center and the blastula chordin noggin expression center (BCNE). Here we will discuss the historical events that led to the discovery of those centers, as well as the molecular mechanisms by which they operate. This chapter highlights the cooperation of both signaling centers with potential to be further explored in the future. We aim to address the essential morphological transformation during gastrulation and neurulation as well as the role of Wnt signaling in patterning the organizer and the neural plate.
摘要：
一个多世纪以来，两栖动物中枢神经系统的发展引起了科学家的关注。对胚胎诱导问题感兴趣，HansSpemann和HildeMangold发现sal胚胎的背胚孔唇具有组织者的特性。这种异位移植物可以在宿主胚胎中诱导结构，包括一个覆盖在完美第二身体轴的脊索上的神经管。几十年后，青蛙Xenopuslaevis作为一种出色的胚胎学实验模型出现，涉及胚胎诱导的开创性概念开始被揭示。所谓的初级感应是,事实上,受精后立即触发的信号和诱导事件的组成。在这方面,自1990年代初以来，已经建立了复杂的信号通路网络。Wnt通路,这在癌症生物学研究中开始被发现，在非洲爪的胚胎发育中建立两个信号中心是至关重要的：Nieuwkoop中心和囊胚腱索蛋白noggin表达中心（BCNE）。在这里，我们将讨论导致发现这些中心的历史事件，以及它们运作的分子机制。本章重点介绍了两个信令中心的合作，将来有可能进一步探索。我们的目标是解决胃泌成和神经化过程中的基本形态转化，以及Wnt信号在组织和神经板图案化中的作用。
