Comparative analysis of pleurodiran and cryptodiran turtle embryos depicts the molecular ground pattern of the turtle carapacial ridge.
Comparative analysis of pleurodiran and cryptodiran turtle embryos depicts the molecular ground pattern of the turtle carapacial ridge.
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DOI：
10.1387/ijdb.140296jp
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Juan Pascual-Anaya;Tatsuya Hirasawa;Iori Sato;Shigehiro Kuraku;S. Kuratani
中科院分区：
文献类型：
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作者：
Juan Pascual-Anaya;Tatsuya Hirasawa;Iori Sato;Shigehiro Kuraku;S. Kuratani
龟壳是一个真正的形态学新奇的极好例子，因为它在任何其他现存的脊椎动物谱系中都没有对应物。贝壳的进化起源是一个让进化生物学家着迷了两个多世纪的问题，它仍然是一个谜。与壳相关的海龟创新之一是背甲脊（CR），这是一个出现在海龟胚胎背侧躯干两侧的凸起，可能控制着背甲的形成，背甲是壳的背部部分。虽然从本世纪开始，现代遗传技术已被应用于解决CR的进化发育起源，使用不同的模型，在原则上，不同的结果阻碍了建立一个共同的机制的起源的壳。虽然现代海龟分为隐颈龟（Cryptodira）和侧颈龟（Pleurodira）两大类，但分子发育研究主要使用隐颈龟模型进行。在这项研究中，我们重新审视了过去的数据，从cryptodiran龟，以调和不同的结果。我们还分析了红腹短颈龟Emydura subglobosa的组织解剖和主要CR因子的表达模式。我们认为，龟壳起源可能伴随着共同选择的经典Wnt信号通路进入CR的最后共同祖先的海龟。
The turtle shell is a wonderful example of a genuine morphological novelty, since it has no counterpart in any other extant vertebrate lineages. The evolutionary origin of the shell is a question that has fascinated evolutionary biologists for over two centuries and it still remains a mystery. One of the turtle innovations associated with the shell is the carapacial ridge (CR), a bulge that appears at both sides of the dorsal lateral trunk of the turtle embryo and that probably controls the formation of the carapace, the dorsal moiety of the shell. Although from the beginning of this century modern genetic techniques have been applied to resolve the evolutionary developmental origin of the CR, the use of different models with, in principle, dissimilar results has hampered the establishment of a common mechanism for the origin of the shell. Although modern turtles are divided into two major groups, Cryptodira (or hidden-necked turtles) and Pleurodira (or side-necked turtles), molecular developmental studies have been carried out mostly using cryptodiran models. In this study, we revisit the past data obtained from cryptodiran turtles in order to reconcile the different results. We also analyze the histological anatomy and the expression pattern of main CR factors in a pleurodiran turtle, the red-bellied short-necked turtle Emydura subglobosa. We suggest that the turtle shell probably originated concomitantly with the co-option of the canonical Wnt signaling pathway into the CR in the last common ancestor of the turtle.