PDF(Pubmed)
Abstract：
Mammalian dentition exhibits distinct heterodonty, with more simple teeth located in the anterior area of the jaw and more complex teeth situated posteriorly. While some region-specific differences in signalling have been described previously, here we performed a comprehensive analysis of gene expression at the early stages of odontogenesis to obtain complete knowledge of the signalling pathways involved in early jaw patterning. Gene expression was analysed separately on anterior and posterior areas of the lower jaw at two early stages (E11.5 and E12.5) of odontogenesis. Gene expression profiling revealed distinct region-specific expression patterns in mouse mandibles, including several known BMP and FGF signalling members and we also identified several new molecules exhibiting significant differences in expression along the anterior-posterior axis, which potentially can play the role during incisor and molar specification. Next, we followed one of the anterior molecules, SATB2, which was expressed not only in the anterior mesenchyme where incisor germs are initiated, however, we uncovered a distinct SATB2-positive region in the mesenchyme closely surrounding molars. Satb2-deficient animals demonstrated defective incisor development confirming a crucial role of SATB2 in formation of anterior teeth. On the other hand, ectopic tooth germs were observed in the molar area indicating differential effect of Satb2-deficiency in individual jaw regions. In conclusion, our data provide a rich source of fundamental information, which can be used to determine molecular regulation driving early embryonic jaw patterning and serve for a deeper understanding of molecular signalling directed towards incisor and molar development.
摘要：
哺乳动物牙列表现出明显的异齿，更简单的牙齿位于颌骨的前部区域，更复杂的牙齿位于后部。虽然先前已经描述了信号传导中的一些区域特异性差异，在这里，我们对牙本质形成早期阶段的基因表达进行了全面分析，以全面了解早期颌骨形成过程中涉及的信号通路。在牙本质发生的两个早期阶段（E11.5和E12.5）分别分析了下颌前部和后部区域的基因表达。基因表达谱分析揭示了小鼠下颌骨中不同的区域特异性表达模式，包括几种已知的BMP和FGF信号成员，我们还鉴定了几种新的分子，这些分子在前后轴的表达上表现出显著差异，它可能在门牙和磨牙规范中起作用。接下来,我们跟踪了一个前分子，SATB2不仅在门牙细菌开始的前间充质中表达，然而,我们在磨牙周围的间充质中发现了一个明显的SATB2阳性区域。Satb2缺陷的动物表现出门牙发育缺陷，证实了SATB2在前牙形成中的关键作用。另一方面,在磨牙区域观察到异位牙胚，表明Satb2缺乏在各个下颌区域的不同作用。总之,我们的数据提供了丰富的基本信息来源，它可用于确定驱动早期胚胎下颌模式的分子调节，并有助于更深入地了解针对切牙和磨牙发育的分子信号。
