Neural induction and patterning in the mouse in the absence of the node and its derivatives
Neural induction and patterning in the mouse in the absence of the node and its derivatives
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DOI：
10.1006/dbio.1999.9525
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发表时间：
1999-12-15
影响因子：
2.7
通讯作者：
Rossant, J
中科院分区：
文献类型：
--
作者：
Klingensmith, J;Ang, SL;Rossant, J
诱导脊椎动物神经组织并使其沿前-后（A-P）轴沿着排列的信号被认为是从Spemann组织器发出的，在哺乳动物中，Spemann组织器是一种称为节点的结构。然而，HNF 3 β的小鼠胚胎突变体缺乏形态学节点和节点衍生物，但仍经历神经诱导。基因表达结构域发生在其正常的A-P轴位置沿着突变神经管在一个明显的正常的时间方式，包括最前面和后面的标记。这种神经模式发生在已知的组织者基因表达的情况下，包括神经诱导剂chordin和noggin。其他潜在的信号中心原肠胚突变体胚胎似乎表达其正常的星座推定的分泌因子，神经诱导和图案信号从别处或在较早的时间发出的可能性一致。然而，我们发现，节点和前原条，从节点的衍生，是神经诱导信号的直接来源，判断早期中脑标记Engrailed的表达，在神经元重组实验。类似的实验表明，HNF 3 β突变体中的神经诱导活性是弥散分布的。我们的研究结果表明，哺乳动物的组织者是能够神经诱导和图案化的神经板，但维护的组织者一样的信号中心是没有必要的过程。(C)北京：科学出版社.
The signals which induce vertebrate neural tissue and pattern it along the anterior-posterior (A-P) axis have been proposed to emanate from Spemann's organizer, which in mammals is a structure termed the node. However, mouse embryos mutant for HNF3 beta lack a morphological node and node derivatives yet undergo neural induction. Gene expression domains occur at their normal A-P axial positions along the mutant neural tubes in an apparently normal temporal manner, including the most anterior and posterior markers. This neural patterning occurs in the absence of expression of known organizer genes, including the neural inducers chordin and noggin. Other potential signaling centers in gastrulating mutant embryos appear to express their normal constellation of putative secreted factors, consistent with the possibility that neural-inducing and -patterning signals emanate from elsewhere or at an earlier time. Nevertheless, we find that the node and the anterior primitive streak, from which the node derives, are direct sources of neural-inducing signals, as judged by expression of the early midbrain marker Engrailed, in explant-recombination experiments. Similar experiments showed the neural-inducing activity in HNF3 beta mutants to be diffusely distributed. Our results indicate that the mammalian organizer is capable of neural induction and patterning of the neural plate, but that maintenance of an organizer like signaling center is not necessary for either process. (C) 1999 Academic Press.