Reactivating head regrowth in a regeneration-deficient planarian species
Reactivating head regrowth in a regeneration-deficient planarian species
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DOI：
10.1038/nature12414
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发表时间：
2013-08-01
期刊：
影响因子：
64.8
通讯作者：
Rink, J. C.
中科院分区：
文献类型：
--
作者：
Liu, S. -Y.;Selck, C.;Rink, J. C.
动物界中存在着能够再生失去的身体部位的物种，但其近亲往往无法再生(1,2)。为什么面对“适者生存”，一些动物能够再生，而另一些动物却不能，这仍然是一个令人着迷的问题(3)。涡虫扁虫以其从微小组织碎片再生的能力而闻名并被研究，但即使在涡虫中也描述了再生能力有限的物种(4)。在这里，我们报告了涡虫乳状腔体再生缺陷的特征及其成功的拯救。从该物种身体后半部切下的组织碎片无法再生头部并最终死亡(5)。我们发现这种缺陷起源于头部规范的早期阶段，这需要抑制其他涡虫物种中的规范 Wnt 信号传导 (6-8)。值得注意的是，RNA 干扰 (RNAi) 介导的 Dlac-beta-catenin-1（Wnt 信号转导器）的敲低恢复了尾部全功能头部的再生，从而挽救了乳球菌的再生缺陷。我们的结果证明了比较研究对于再生缺陷动物的再生能力的重新激活的效用。此外，D.lacteum作为再生受损的涡虫模型物种的可用性为阐明最终决定为什么一些动物能够再生而另一些动物不能再生的进化机制迈出了第一步。
Species capable of regenerating lost body parts occur throughout the animal kingdom, yet close relatives are often regeneration incompetent(1,2). Why in the face of 'survival of the fittest' some animals regenerate but others do not remains a fascinating question(3). Planarian flatworms are well known and studied for their ability to regenerate from minute tissue pieces, yet species with limited regeneration abilities have been described even amongst planarians(4). Here we report the characterization of the regeneration defect in the planarian Dendrocoelum lacteum and its successful rescue. Tissue fragments cut from the posterior half of the body of this species are unable to regenerate a head and ultimately die(5). We find that this defect originates during the early stages of head specification, which require inhibition of canonical Wnt signalling in other planarian species(6-8). Notably, RNA interference (RNAi)-mediated knockdown of Dlac-beta-catenin-1, the Wnt signal transducer, restored the regeneration of fully functional heads on tail pieces, rescuing D. lacteum's regeneration defect. Our results demonstrate the utility of comparative studies towards the reactivation of regenerative abilities in regeneration-deficient animals. Furthermore, the availability of D. lacteum as a regeneration-impaired planarian model species provides a first step towards elucidating the evolutionary mechanisms that ultimately determine why some animals regenerate and others do not.