中文摘要：

目的：检测Ddit3在小鼠下颌第一磨牙牙胚不同时期的表达分布及变化规律,初步揭示Ddit3在小鼠牙胚发育中的作用。方法：取不同胚胎时间点的ICR妊娠小鼠,制备牙胚发育标本,通过免疫荧光和免疫组化的方法显示Ddit3在小鼠下颌第一磨牙牙胚发育不同时间点的表达分布。结果：Ddit3在牙胚发育的早期主要表达于胞浆中,从钟状期开始,Ddit3不仅在胞浆中有阳性表达,同时也微弱地表达于细胞核中。分布如下：在小鼠下颌第一磨牙发育的板状期,Ddit3几乎没有表达。在蕾状期,Ddit3主要表达于釉上皮的细胞质中,在牙外胚间充质细胞中几乎无表达。在帽状期,Ddit3的表达模式基本和蕾状期相同。在钟状期早期,Ddit3在成釉细胞、前成牙本质细胞和牙乳头胞质中呈阳性表达,在部分细胞核中也检测到了Ddit3的表达。钟状期晚期,Ddit3在新形成的硬组织周围的高柱状成釉细胞、成牙本质细胞和牙乳头细胞的胞浆中有阳性表达,在大多数成釉细胞、成牙本质细胞和牙乳头细胞的细胞核中也有表达。结论：Ddit3可能会调节成釉细胞和成牙本质细胞的分化及其硬组织的生物矿化。

英文摘要：

Objective：To investigate the temporal and spatial expression pattern of Ddit3 during the first molar development and tentatively uncover the functional role of Ddit3 during tooth development.Methods：Time pregnancy ICR mouse embryos was obtained and serially sectioned for immunofluorescence and immunocytochemistry staining.Results：During the early development,Ddit3 was mainly expressed in the cytoplasm of mouse first molar tooth germ.From the early bell stage,Ddit3 was not only expressed in the cytoplasm,but also weakly expressed in the nucleus.Expression pattern was as follows：in the laminae stage,there was no expression of Ddit3 neither in oral epithelium and mesenchymal cells;in the bud stage,the expression of Ddit3 was located in the cytoplasm of dental epithelium cells as well as in the cap stage;in the early bell stage,Ddit3 had an expression in the cytoplasm of ameloblasts,pre-odontoblasts and dental papilla cells.Ddit3 was also expressed in the nucleus of those cells.In the late bell stage,Ddit3 was expressed in the cytoplasm of high columnar ameloblasts and odontoblasts nearby the newly formed hard tissues.Furthermore,Ddit3 was also expressed in the nucleus of the most ameloblasts,odontoblasts and dental papilla cells.Conclusion：Ddit3may play a vital role in the differentiation of ameloblasts,odontoblasts and biomineralization process.