Expression of Sympathetic Nervous System Genes in Lamprey Suggests Their Recruitment for Specification of a New Vertebrate Feature
Expression of Sympathetic Nervous System Genes in Lamprey Suggests Their Recruitment for Specification of a New Vertebrate Feature
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DOI：
10.1371/journal.pone.0026543
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发表时间：
2011-10-27
期刊：
影响因子：
3.7
通讯作者：
Bronner-Fraser, Marianne
中科院分区：
文献类型：
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作者：
Haeming, Daniela;Simoes-Costa, Marcos;Bronner-Fraser, Marianne
海七鳃鳗是一种基部无颌脊椎动物，拥有许多神经嵴衍生物，但缺乏颌和交感神经节。这就提出了一种可能性，即参与交感神经元分化的因素要么是一种颚口创新，要么已经存在于七鳃鳗中，但服务于不同的目的。为了区分这些可能性，我们分离出七鳃鳗同源物的转录因子与外周神经节的形成，并研究其部署在七鳃鳗胚胎。我们进一步进行了Dil标记的神经管结合神经元标记物，以测试是否神经嵴衍生的细胞迁移到和分化的网站由交感神经节在有颌脊椎动物的殖民。与以前的成人解剖数据一致，我们在七鳃鳗胚胎中的研究结果表明，神经嵴细胞不能迁移腹侧形成交感神经节，虽然它们确实形成邻近神经管的背根神经节。有趣的是，然而，旁系同源的电池的转录因子介导的交感神经元分化（dHand，Ascl1和Phox2b）存在于七鳃鳗基因组中，并在胚胎中的各个位点表达，但未能在任何神经节结构重叠。这提出了一个有趣的可能性，他们可能已被招募在nathostome进化到一个新的功能，在神经嵴衍生物。
The sea lamprey is a basal, jawless vertebrate that possesses many neural crest derivatives, but lacks jaws and sympathetic ganglia. This raises the possibility that the factors involved in sympathetic neuron differentiation were either a gnathostome innovation or already present in lamprey, but serving different purposes. To distinguish between these possibilities, we isolated lamprey homologues of transcription factors associated with peripheral ganglion formation and examined their deployment in lamprey embryos. We further performed Dil labeling of the neural tube combined with neuronal markers to test if neural crest-derived cells migrate to and differentiate in sites colonized by sympathetic ganglia in jawed vertebrates. Consistent with previous anatomical data in adults, our results in lamprey embryos reveal that neural crest cells fail to migrate ventrally to form sympathetic ganglia, though they do form dorsal root ganglia adjacent to the neural tube. Interestingly, however, paralogs of the battery of transcription factors that mediate sympathetic neuron differentiation (dHand, Ascl1 and Phox2b) are present in the lamprey genome and expressed in various sites in the embryo, but fail to overlap in any ganglionic structures. This raises the intriguing possibility that they may have been recruited during gnathostome evolution to a new function in a neural crest derivative.