小鼠牙齿发育中Pax-9的表达及意义

目的 通过观察PAX-9在牙发育中的分布及变化规律，探索牙齿发生的机制。方法 标本为妊娠10．5～18．5天昆明小鼠分别取胎鼠，分别作HE染色和免疫组化染色，图像分析仪分析。结果 Pax-9表达于胞浆中。蕾状期，牙蕾上皮及间充质细胞不表达Pax-9；帽状期牙乳头细胞表达较强；钟状期早期成牙本质细胞或前成牙本质细胞表达强阳性，内釉上皮细胞、星网状层细胞及牙乳头细胞有微弱表达；钟状期晚期成牙本质细胞、成釉细胞、及釉牙本质界处集中表达，新形成的釉质和前期牙本质染色较强。结论 PAX-9促进牙胚从蕾状期向帽状期转变，调节钟状期成牙本质细胞及成釉细胞的分化及基质分泌，并参与生物矿化过程。

Expression of Pax9 during tooth development in mice

Objective To examine the expression of Pax9 during mousce tooth development. Methods Embryos were obtained from mice in pregnancy of 10.5 - 18.5 days and serially sectioned for HE and immunohistochemical staining, respectively. Results In the bud stage, the expression of Pax9 was not observed in the epithelium and mesenchyme. In the cap stage, the expression of Pax9 was observed strongly in the cytoplasm of dental papilla. In the early bell stage, Pax9 was expressed strongly in odontoblast and preodontoblast, but weekly in the inner enamel epithelium, stellate reticulum and dental papilla. In the late bell stage, Pax9 was abundant in odontoblast, ameloblast and enamel - dentinal junction. Pax9 was also observed in the new formed enamel and predentin. Conclusion Pax9 may play an important role in the tooth development to proceed beyond the bud stage.