Wnt信号通路与后口动物体轴的进化发育

Wnt signaling pathway and the Evo-Devo of deuterostome axis

动物体轴极性的建立和最初胚轴的形成涉及到一系列信号通路的调控,Wnt信号通路是其中一条十分保守的信号通路,并且Wnt/β-catenin信号通路中的关键成员早在海绵动物中就有发现,暗示这一信号通路相对于其他信号路径来说可能是最早参与原始后生动物体轴发育的信号通路之一,并且在体轴后端和腹部的发育及命运分化方面发挥着重要作用。近年来,随着体外功能实验体系的建立,人们发现Wnt信号通路中很多基因都不同程度地影响了早期胚轴的形成,例如wnt基因、母源性基因β-catenin以及一系列转录因子等。文章首先对参与后生动物体轴发育的wnt基因家族的起源与进化关系做一简要分析,并进一步就经典的Wnt/β-catenin通路与后口动物的海胆、文昌鱼、斑马鱼、爪蟾和小鼠等类群体轴极性的建立乃至整个体轴形成方面的研究进展做一综述。

A series of signal transduction pathways have been found to regulate the polarity establishment and formation of animal primary body axis.Among them,Wnt signaling pathway is extremely conserved and several key components in the pathway have been identified in the demosponge lineage.This implies that it is one of the earliest pathways involved in the ancestral metazoan axis development and might play an important role in specification and development of posterior and ventral fate of animal axis.Recently,with the establishment of functional experiments in vitro,the body plan formation has been found to be affected,in varying degrees,by many genes in the Wnt signaling pathway,such as members of wnt gene family,maternal gene β-catenin and some transcription factor encoding genes.In this review,we analyzed the evolu-tionary origin of the wnt gene family involved in development of metazoan body plans,and then made a brief review on the roles of canonical Wnt/β-catenin signaling in the polarity establishment and formation of primary body axis in diverse deu-terostomes including sea urchin,amphioxus,zebrafish,frog,and mouse.