Continuing organizer function during chick tail development.
Continuing organizer function during chick tail development.
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发表时间：
1998-05
期刊：
影响因子：
4.6
通讯作者：
Vladimir Knezevic;Ron De Santo;S. Mackem
中科院分区：
文献类型：
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作者：
Vladimir Knezevic;Ron De Santo;S. Mackem
脊椎动物后体（腰骶区和尾巴）的发育相对于原肠胚形成延迟。在羊膜动物中，退化的淋巴结和原始条纹被尾端胚状间质团块（称为尾芽）所取代。尽管存在明显的形态差异，但最近的研究结果表明，羊膜动物的尾巴发育本质上是原肠胚形成的延续，非洲爪蟾也是如此。然而，这主要是从命运图谱研究的结果推断出来的，这些研究表明，尾芽中存在离散的、区域化的细胞群，就像原肠胚一样。我们对鸡原肠形成过程中在特定空间域中表达的几个分子标记的尾芽分布的分析证实了这些结果。此外，我们提供的证据表明，在早期的鸡尾芽中，从表面开始的类似原肠胚的侵入运动继续进行，并且已建立的尾芽保留了组织者活动。这种“尾部组织者”具有预期的特性，能够将未确定的宿主细胞招募到新的胚胎轴上，并在移植到有能力的宿主细胞（否则注定只能形成胚胎外组织）时诱导具有后区域化基因表达的宿主神经组织。综上所述，这些结果表明，鸡尾的发育在机械上与原肠形成是连续的，考虑到残余的尾巴组织活动在令人惊讶的后期仍然存在，鸡尾的发育可以作为研究原肠形成过程中诱导相互作用的分子基础的有用实验辅助手段。
Development of the posterior body (lumbosacral region and tail) in vertebrates is delayed relative to gastrulation. In amniotes, it proceeds with the replacement of the regressed node and primitive streak by a caudal blastema-like mass of mesenchyme known as the tail bud. Despite apparent morphological dissimilarities, recent results suggest that tail development in amniotes is in essence a continuation of gastrulation, as is the case in Xenopus. However, this has been inferred primarily from the outcome of fate mapping studies demonstrating discrete, regionalized cell populations in the tail bud, like those present at gastrulation. Our analysis of the tail bud distribution of several molecular markers that are expressed in specific spatial domains during chick gastrulation confirms these results. Furthermore, we present evidence that gastrulation-like ingression movements from the surface continue in the early chick tail bud and that the established tail bud retains organizer activity. This 'tail organizer' has the expected properties of being able to recruit uncommitted host cells into a new embryonic axis and induce host neural tissue with posteriorly regionalized gene expression when grafted to competent host cells that are otherwise destined to form only extra-embryonic tissue. Together, these results indicate that chick tail development is mechanistically continuous with gastrulation and that the developing tail in chick may serve as a useful experimental adjunct to investigate the molecular basis of inductive interactions operating during gastrulation, considering that residual tail organizing activity is still present at a surprisingly late stage.