Spatial and temporal pattern for the dentition in the Australian lungfish revealed with sonic hedgehog expression profile
Spatial and temporal pattern for the dentition in the Australian lungfish revealed with sonic hedgehog expression profile
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DOI：
10.1098/rspb.2008.1364
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发表时间：
2009-02-22
影响因子：
4.7
通讯作者：
Joss, Jean
中科院分区：
文献类型：
--
作者：
Smith, Moya M.;Okabe, Masataka;Joss, Jean
我们报告的时间顺序的牙齿除了在澳大利亚肺鱼的牙齿诱导的时间是连续的，在相同的模式，硬骨鱼沿着下颌。新角龙的牙齿发生顺序是从中线牙齿开始，在颌位2处有左右牙齿，然后是3，然后是1。这是几种硬骨鱼的齿的模式顺序，我们提出的是一个刻板的启动模式与所有硬骨鱼类，包括生活的姐妹组，所有四足动物，澳大利亚肺鱼共享。这与以前的观点相反，即肺鱼的齿系是以其他方式衍生的，并且是独特的。声波刺猬（shh）表达强烈集中在牙齿的位置在不同的时间对应于他们的启动顺序。这种shh的部署是肺鱼牙齿诱导所必需的，因为环巴胺治疗会导致这些牙齿在发育之前完全丧失。牙齿开始的时间顺序可能是由shh调节，并且已知是其他硬骨鱼类，包括慈鲷鱼和蛇的齿系模式所需的。这反映了一个共同的发展过程与颌骨脊椎动物在牙齿模块的水平，但不同的替代牙齿的缺乏。
We report a temporal order of tooth addition in the Australian lungfish where timing of tooth induction is sequential in the same pattern as osteichthyans along the lower jaw. The order of tooth initiation in Neoceratodus starts from the midline tooth, together with left and right ones at jaw position 2, followed by 3 and then 1. This is the pattern order for dentary teeth of several teleosts and what we propose represents a stereotypic initiation pattern shared with all osteichthyans, including the living sister group to all tetrapods, the Australian lungfish. This is contrary to previous opinions that the lungfish dentition is otherwise derived and uniquely different. Sonic hedgehog (shh) expression is intensely focused on tooth positions at different times corresponding with their initiation order. This deployment of shh is required for lungfish tooth induction, as cyclopamine treatment results in complete loss of these teeth when applied before they develop. The temporal sequence of tooth initiation is possibly regulated by shh and is know to be required for dentition pattern in other osteichthyans, including cichlid fish and snakes. This reflects a shared developmental process with jawed vertebrates at the level of the tooth module but differs with the lack of replacement teeth.