Nonindependence of mammalian dental characters
Nonindependence of mammalian dental characters
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DOI：
10.1038/nature02927
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发表时间：
2004-11-11
期刊：
影响因子：
64.8
通讯作者：
Jernvall, J
中科院分区：
文献类型：
--
作者：
Kangas, AT;Evans, AR;Jernvall, J
哺乳动物进化的研究经常使用来自齿系的数据（1-4）。牙齿特征对于推断化石分类群（1-4）的系统发育关系特别重要，其中牙齿通常是唯一恢复的部分。使用牙齿形态的不同方面作为系统发育的信号意味着牙齿字符彼此独立。在这里，我们报告，然而，至少在发展中，大多数牙齿字符可能是非独立的。我们研究了三种不同水平的细胞信号蛋白外胚层发育不良（Eda）（5）如何改变小鼠的牙齿特征。我们发现，随着这一基因表达水平的增加，牙尖的数量增加，牙尖的形状和位置发生变化，纵嵴形成，牙齿数量增加。与尖瓣的侧向放置相关的字符的一致修改可以追溯到在牙冠形成开始时形成早期信号中心的微小差异。我们的研究结果表明，大多数方面的牙齿形状有发展潜力的相关变化在进化过程中，如果不考虑到，模糊的系统发育史。
Studies of mammalian evolution frequently use data derived from the dentition(1-4). Dental characters are particularly central for inferring phylogenetic relationships of fossil taxa(1-4), of which teeth are often the only recovered part. The use of different aspects of dental morphology as phylogenetic signals implies the independence of dental characters from each other. Here we report, however, that, at least developmentally, most dental characters may be nonindependent. We investigated how three different levels of the cell signalling protein ectodysplasin (Eda)(5) changed dental characters in mouse. We found that with increasing expression levels of this one gene, the number of cusps increases, cusp shapes and positions change, longitudinal crests form, and number of teeth increases. The consistent modification of characters related to lateral placement of cusps can be traced to a small difference in the formation of an early signalling centre at the onset of tooth crown formation. Our results suggest that most aspects of tooth shape have the developmental potential for correlated changes during evolution which may, if not taken into account, obscure phylogenetic history.