Notochord-derived hedgehog is essential for tail regeneration in Xenopus tadpole.
Notochord-derived hedgehog is essential for tail regeneration in Xenopus tadpole.
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DOI：
10.1186/1471-213x-14-27
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发表时间：
2014-06-18
影响因子：
--
通讯作者：
Mochii M
中科院分区：
文献类型：
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作者：
Taniguchi Y;Watanabe K;Mochii M
两栖动物的胚胎再生受信号分子的组合作用调控。从特定组织分泌的分子的需求反映在观察到，如果从截肢残端移除特定组织，则再生的整个过程可以被抑制。有趣的是，有尾目和无尾目在尾部再生过程中表现出不同的组织依赖性。脊髓是尾再生所必需的有尾目，而不是在无尾类幼体，而脊索，而不是脊髓是必不可少的无尾类蝌蚪的尾巴再生。Sonic Hedgehog是导致蝾螈这种现象的信号分子之一，因为Hedgehog信号对于整体尾部再生至关重要，而Sonic Hedgehog仅在脊髓中表达。为了了解刺猬信号是否参与了无尾两栖类和有尾目之间不一致的尾再生组织依赖性的分子机制，我们研究了刺猬信号相关基因在非洲爪蟾蝌蚪再生尾中的表达，并研究了刺猬信号抑制剂环巴胺对尾再生的影响。在非洲爪蟾中，Sonic Hedgehog仅在再生的脊索中表达，而不在脊髓中表达。环巴胺处理的蝌蚪整体再生严重受损。再生过程中脊索的成熟，包括细胞排列和空泡化，以及肌纤维的形成受到抑制。神经壶腹和间充质细胞的脊髓细胞的增殖也受损。在蝾螈，刺猬信号是需要在爪蟾蝌蚪的尾巴再生的多个步骤，虽然嘘源的位置是完全不同的两个物种之间。Shh定位的这种差异可能是有尾目和无尾目之间尾部再生的不同组织要求的基础。
Appendage regeneration in amphibians is regulated by the combinatorial actions of signaling molecules. The requirement of molecules secreted from specific tissues is reflected by the observation that the whole process of regeneration can be inhibited if a certain tissue is removed from the amputated stump. Interestingly, urodeles and anurans show different tissue dependencies during tail regeneration. The spinal cord is essential for tail regeneration in urodele but not in anuran larva, whereas the notochord but not the spinal cord is essential for tail regeneration in anuran tadpoles. Sonic hedgehog is one of the signaling molecules responsible for such phenomenon in axolotl, as hedgehog signaling is essential for overall tail regeneration and sonic hedgehog is exclusively expressed in the spinal cord. In order to know whether hedgehog signaling is involved in the molecular mechanism underlying the inconsistent tissue dependency for tail regeneration between anurans and urodeles, we investigated expression of hedgehog signal-related genes in the regenerating tail of Xenopus tadpole and examined the effect of the hedgehog signal inhibitor, cyclopamine, on the tail regeneration. In Xenopus, sonic hedgehog is expressed exclusively in the notochord but not in the spinal cord of the regenerate. Overall regeneration was severely impaired in cyclopamine-treated tadpoles. Notochord maturation in the regenerate, including cell alignment and vacuolation, and myofiber formation were inhibited. Proliferation of spinal cord cells in the neural ampulla and of mesenchymal cells was also impaired. As in the axolotl, hedgehog signaling is required for multiple steps in tail regeneration in the Xenopus tadpole, although the location of the Shh source is quite different between the two species. This difference in Shh localization is the likely basis for the differing tissue requirement for tail regeneration between urodeles and anurans.