Sox2 marks epithelial competence to generate teeth in mammals and reptiles
Sox2 marks epithelial competence to generate teeth in mammals and reptiles
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DOI：
10.1242/dev.089599
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发表时间：
2013-04-01
期刊：
影响因子：
4.6
通讯作者：
Thesleff, Irma
中科院分区：
文献类型：
--
作者：
Juuri, Emma;Jussila, Maria;Thesleff, Irma
牙齿更新是从与现有牙齿相关的上皮细胞开始的。新牙齿的发育需要具有牙齿形成能力的牙上皮细胞，但这些细胞的特异性标记基因尚未确定。在这里，我们分析了转录因子Sox 2的表达模式在两种不同的模式的连续牙齿形成：牙齿更换和连续增加的乳牙。我们观察到特定的Sox 2表达的牙板，引起连续的牙齿在哺乳动物的一轮牙齿更换，以及在爬行动物的连续牙齿更换。Sox 2也在哺乳动物磨牙的连续添加过程中在牙板中表达，并且遗传谱系追踪表明第一磨牙的Sox 2（+）细胞引起第二和第三磨牙的上皮细胞谱系。此外，Sox 2的条件性缺失导致形成中的后磨牙上皮增生。我们的研究结果表明，Sox 2（+）牙上皮细胞具有连续性牙齿形成的能力，Sox 2调节牙上皮细胞的祖细胞状态。研究结果表明，Sox 2的功能在进化过程中一直保持不变，牙齿替换和乳牙的连续增加代表了同一发育过程的变化。Sox 2的表达模式支持哺乳动物存在持续牙齿更新的休眠能力的假设。
Tooth renewal is initiated from epithelium associated with existing teeth. The development of new teeth requires dental epithelial cells that have competence for tooth formation, but specific marker genes for these cells have not been identified. Here, we analyzed expression patterns of the transcription factor Sox2 in two different modes of successional tooth formation: tooth replacement and serial addition of primary teeth. We observed specific Sox2 expression in the dental lamina that gives rise to successional teeth in mammals with one round of tooth replacement as well as in reptiles with continuous tooth replacement. Sox2 was also expressed in the dental lamina during serial addition of mammalian molars, and genetic lineage tracing indicated that Sox2(+) cells of the first molar give rise to the epithelial cell lineages of the second and third molars. Moreover, conditional deletion of Sox2 resulted in hyperplastic epithelium in the forming posterior molars. Our results indicate that the Sox2(+) dental epithelium has competence for successional tooth formation and that Sox2 regulates the progenitor state of dental epithelial cells. The findings imply that the function of Sox2 has been conserved during evolution and that tooth replacement and serial addition of primary teeth represent variations of the same developmental process. The expression patterns of Sox2 support the hypothesis that dormant capacity for continuous tooth renewal exists in mammals.