Requirement for Wnt3 in vertebrate axis formation
Requirement for Wnt3 in vertebrate axis formation
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DOI：
10.1038/11932
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发表时间：
1999-08-01
期刊：
影响因子：
30.8
通讯作者：
Bradley, A
中科院分区：
文献类型：
--
作者：
Liu, PT;Wakamiya, M;Bradley, A
多项研究表明，Wnt信号通路在脊椎动物胚胎发生过程中的主轴形成中起作用，但尚未有任何一种Wnt蛋白被证明对这一过程是必不可少的（1 - 3）。在小鼠中，原条形成是前后轴的第一个明显的形态学标志。在此我们发现，Wnt3在原肠胚形成之前在卵柱近端的上胚层中表达，随后局限于后近端上胚层及其相关的脏内胚层，接着在原条和中胚层中表达。Wnt3（-/-）小鼠能发育出正常的卵柱，但不能形成原条、中胚层。上胚层持续在未分化状态下增殖，缺乏前后神经模式，但前脏内胚层标志物得以表达且位置正确。我们的研究结果表明，脏内胚层的区域模式形成与原条形成无关，但外胚层中前后神经模式的后续建立依赖于原条的衍生物。这些研究为Wnt3在小鼠主轴形成中的必要性提供了遗传学证据。
Several studies have implicated Wnt signalling in primary axis formation during vertebrate embryogenesis, yet no Wnt protein has been shown to be essential for this process(1-3), In the mouse, primitive streak formation is the first overt morphological sign of the anterior-posterior axis, Here we show that Wnt3 is expressed before gastrulation in the proximal epiblast of the egg cylinder, then is restricted to the posterior proximal epiblast and its associated visceral endoderm and subsequently to the primitive streak and mesoderm, Wnt3(-/-) mice develop a normal egg cylinder but do not form a primitive streak, mesoderm or The epiblast continues to proliferate in an undifferentiated state that lacks anterior-posterior neural patterning, but anterior visceral endoderm markers are expressed and correctly positioned. Our results suggest that regional patterning of the visceral endoderm is independent of primitive streak formation, but the subsequent establishment of anterior-posterior neural pattern in the ectoderm is dependent on derivatives of the primitive streak. These studies provide genetic proof for the requirement of Wnt3 in primary axis formation in the mouse.