Smad4条件基因敲除小鼠内耳前庭的组织学变化

Histological changes of peripheral vestibular organs in the inner ears of Smad4 conditional knockoutmice

目的观察Smad4条件基因敲除小鼠内耳前庭的组织学变化，探讨Smad4基因在内耳前庭发育中的作用。方法应用冰冻切片、免疫荧光化学、激光扫描共聚焦显微镜、扫描电镜、透射电镜等技术，观察软骨组织Smad4条件基因敲除小鼠内耳前庭组织形态的变化。结果Smad4一／一小鼠内耳软骨囊Smad4免疫反应阴性，Smad4＋／一小鼠阳性，Smad4＋／＋小鼠强阳性，而在前庭感觉上皮——壶腹嵴和囊斑里Smad4免疫反应均呈阳性，三个基因型间没有差别；通过扫描电镜和透射电镜以及神经丝免疫荧光染色观察，三个基因型小鼠内耳前庭均未发现病变。结论Smad4条件基因敲除小鼠的内耳软骨囊里Smad4基因被有效剔除，但其对内耳前庭的组织结构和形态影响有限。

Objective To investigate the histological changes in the vestibular endorgans of Smad4 gene conditional knockout mice and to explore the influence of the Smad4 gene on vestibular development. Methods Histological changes of periphery vestibular organs in inner ear of Smad4 conditional knockout mice were investigated by frozen sections, immunofluorescence, confocal microscopy, scanning electron microscopy and transmission electron microscopy. Results There was no Smad4 expression in the inner ear cartilage capsule of Smad4 -/- mice. In Smad4 ＋/- mice, Smad4 expression in the same cartilage capsule was positive, and it was strong positive in Smad4 ＋/＋ mice. Smad4 expression in vestibular sense epithelium, crista ampullaris and macula, was positive. And no difference was found among these three genotypes. Studying at scanning electron microscopy and transmission electron microscopy levels and anti- filament immunofluorescence showed that no pathological changes were observed in all the three genotype mice. Conclusion Although the Smad4 gene was knockout effectively in the auricular cartilage capsule of Smad4 conditional knockout mice, the histological changes of Smad4 conditional knockout mice in vestibulum auris internae were slightly.