BALB/c小鼠下颌第一磨牙的动态组织学观察

Mouse tooth development time sequence determination for the BALB/c strain

目的对BALB/c小鼠下颌第一磨牙发育过程进行动态观察,从组织形态学掌握出生前BALB/c小鼠牙胚的发育规律。方法选取胚胎期(E)10.5、11.5、12.5、13.5、14.5、15.5、16.5、17.5、18.5、19.5的胚鼠,E10.5～15.5取胚鼠头部直接固定包埋,E16.5～19.5在体视显微镜下分离下颌骨,脱矿后包埋,连续切片后HE染色,在光学显微镜下进行观察,了解BALB/c小鼠牙胚发育的过程及变化规律。结果在E11.5小鼠下颌第一磨牙磨牙区口腔上皮细胞增生,形成牙板;E12.5为牙板向蕾状期的过渡期;E13.5进入蕾状期;E14.5～15.5胚鼠的下颌第一磨牙牙胚处于帽状期;E16.5～19.5胎鼠处于钟状期。结论本实验确定了BALB/c下颌第一磨牙的发育规律,为利用BALB/c作为模式动物进行牙发育机制奠定实验基础。

Objective To establish the normal dental development pattern of the BALB/c strain of mouse,it was analyzed a significant number of observations of the different developmental stages of the first mandibular molar,accurately recording the chronology of their daily embryonic development. Methods Embryo mice of E10.5,E11.5,E12.5,E13.5,E14.5,E15.5,E16.5,E17.5,E18.5,E19.5 days old were selected.Female mice were sacrificed for cervical dislocation.The whole embryos were collected at E11.5-E16.5.The jaws were from embryonic mice at E17.5-E19.5.The serial sections were taken and stained by HE.The developmental stages of the tooth germs were judged from the tissue sections according to morphological criteria. Results Proliferation of the dental sheet began at E11.5,the bud stage appeared at days E13.5.The cap stage was observed at day E14.5 and E15.5 and the early bell stage at E16.5 and E17.5.The predentin was observed at day E18.5. Conclusion This study explicated the space-time changing rules of development of BALB/c strain of mouse.The establishment of this development pattern will be useful for future investigations.