Shh、Ptch1及Ptch2基因在小鼠磨牙发育过程中的表达

Expression of Shh,Ptch1 and Ptch2 mRNA during the development of mouse molar

目的通过原位杂交的方法研究Sonic Hedgehog(Shh)、Patched1(Ptch1)及Patched2(Ptch2)在小鼠下颌磨牙发育过程中的表达,以探讨该信号通路在牙胚发育中的作用。方法制备小鼠下颌第一磨牙发育各期标本,原位杂交检测Shh、Ptch1及Ptch2的表达部位及强度。结果Shh在帽状期表达于釉结,钟状早期表达于内釉上皮,钟状晚期表达于成釉细胞;Ptch1在帽状期表达于牙囊、外釉上皮及星网状层,钟状早期表达于牙囊、外釉上皮及牙乳头,钟状晚期表达于成牙本质细胞及牙乳头;Ptch2在帽状期表达于釉结,钟状早期表达于内釉上皮,钟状晚期无表达。结论Shh信号系统在牙胚发育各期有各自的表达特点,提示可能在牙胚形态的调控,成釉细胞、成牙本质细胞分化的诱导中起重要作用。

Objective To investigate the expression of Sonic Hedgehog （ Shh）, Patchedl （ Ptch1 ） and Patched2 （Ptch2） during the development of mouse molar. Methods Different stages of tooth germs were obtained from mouse. The expression of Shh,Ptch1 and Ptch2 were observed by in situ hybridization. Results Shh was expressed in enamel knot, inner enamel epithelium and ameloblasts respectively during the three stages. Ptch1 was expressed in dental follicle, outer enamel epithelium, stellate reticulum during cap stage, in dental follicle,outer enamel epithelium and dental papilla during early bell stage, and in odontoblasts and dental papilla during late bell stage. Ptch2 was expressed in enamel knot during cap stage, in inner enamel epithelium during early bell stage, and not found during late bell stage. Conclusion Shh signaling can be expressed in the developing mouse molar in different manner, which indicates that Shh signaling may play an important role in the regulation of tooth morphogenesis and the induction of ameloblasts and odontoblasts cytodifferentiation.