Notch1在小鼠下颌第一磨牙牙胚发育中的表达

目的探讨Notch1在小鼠下颌第一磨牙胚胎发育过程中的组织学分布。方法制作ICR小鼠下颌第一磨牙不同发育阶段的冰冻组织切片,对小鼠下颌第一磨牙自牙胚发育起始期至出生后2天不同发育阶段组织的Notch1分布情况进行免疫组织化学染色。结果 Notch1在小鼠下颌第一磨牙牙胚发育起始期和蕾状期牙板上皮上方或其包绕的口腔上皮中表达,在牙板上皮中没有表达。自帽状期至钟状期,Notch1在牙胚的中间层表达,而在内釉上皮中无表达。至牙釉质和牙本质分泌期,Notch1仍在颈环部位的中间层表达。此外,Notch1还在牙胚发育不同时期的间充质、牙乳头和早期牙髓中表达。结论 Notch1可能在小鼠下颌第一磨牙发育过程中的牙上皮特别是内釉上皮的细胞分化,以及牙囊和牙乳头细胞分化及分化完成后的牙髓干细胞的稳定性方面有重要作用。

Expression of Notch1 in developing mouse molar tooth germ

Objective To investigate the expression of Notch1 in developing mouse molar tooth germ. Methods Cryosections of developing ICR mouse first molar tooth germ at different developmental stages were made. The expression of Notch1 in the tooth germ tissues was examined by immunohistochemistry. Results Notch1 was expressed in the oral epithelium above or surrounded by the dental placode at initial dental lamina and tooth bud stages,but not expressed in dental placode. From dental cap to bell stage,Notch1 was expressed in stratum intermedium but not in inner enamel epithelium. At enamel and dentin secreting stage,Notch1 was still expressed in the stratum intermedium of the cervical loop. Moreover,Notch1 was also expressed in the mesenchyme,dental papillae and early dental pulp throughout the developing process. Conclusion Notch1 may play an important role in the dental epithelial cell,especially the inner enamel epithelial cell differentiation during the mouse molar tooth germ development and may also be needed in dental follicle,dental papillae and dental pulp cell development and homeostasis.