Evolutionary modification of development in mammalian teeth:: Quantifying gene expression patterns and topography
Evolutionary modification of development in mammalian teeth:: Quantifying gene expression patterns and topography
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DOI：
10.1073/pnas.97.26.14444
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发表时间：
2000-12-19
影响因子：
11.1
通讯作者：
Thesleff, I
中科院分区：
文献类型：
--
作者：
Jernvall, J;Keränen, SVE;Thesleff, I
哺乳动物进化的研究往往依赖于牙齿形态的详细分析。对于分子模式在牙齿进化中发挥作用，基因表达差异应与相应的形态差异相联系。因为牙齿，像许多其他结构，是复杂的，新的形状的演变通常涉及微妙的变化，我们已经开发了地形的方法，通过使用地理信息系统。我们研究了上皮细胞信号中心的遗传标记（称为釉质结）如何与两种啮齿类动物（小鼠和老鼠）牙齿mof的进化分歧相关。我们分析了Fgf4、Lef1、p21.和Shh基因与发育中牙齿形状的数字高程模型的关系表明，分子预模式提前一天以上预测侧尖地形。分子前模式的异位转变可能与小鼠磨牙的进化有关，改变了历史上同源牙尖形成的位置。这种微妙但可测量的异位移位可能在牙尖地形的演变中发挥重要作用。然而，在田鼠磨牙的纵向牙尖的数量的进化增加涉及加速纵向生长和迭代添加新的尖没有变化的侧向尖地形。建立侧尖地形后，尖的迭代添加可能会限制在进化研究中使用的个体形态特征的独立性。哺乳动物臼齿形态的多样性很大程度上可能是由异位和迭代过程造成的。
The study of mammalian evolution often relies on detailed analysis of dental morphology. For molecular patterning to play a role in dental evolution, gene expression differences should be linkable to corresponding morphological differences. Because teeth, like many other structures, are complex and evolution of new shapes usually involves subtle changes, we have developed topographic methods by using Geographic Information Systems. We investigated how genetic markers for epithelial signaling centers known as enamel knots are associated with evolutionary divergence of mof at teeth in two rodent species, mouse and vote. Our analysis of expression patterns of Fgf4, Lef1, p21. and Shh genes in relation to digital elevation models of developing tooth shapes shows that molecular prepatterns predict the lateral cusp topography more than a day in advance. A heterotopic shift in the molecular prepatterns can be implicated in the evolution of mouse molar, changing locations from which historically homologous cusps form. The subtle but measurable heterotopic shifts may play a large role in the evolution of tooth cusp topographies. However, evolutionary increase in the number of longitudinal cusps in vole molar has involved accelerated longitudinal growth and iterative addition of new cusps without changes in lateral cusp topography. The iterative addition of cusps after the establishment of lateral cusp topography may limit the independence of individual morphological features used in evolutionary studies. The diversity of mammalian molar patterns may largely result from the heterotopic and iterative processes.