C57BL/6小鼠内耳前庭末梢器官的形态发育过程及Myosin Ⅵ的表达

Morphological development process of periphery vestibular organs in inner ear and expression of myosin VI in C57BL/6 mice

目的探讨C57BL/6小鼠内耳前庭末梢器官的形态发育过程及MyosinⅥ在该过程中的表达。方法选择从E10到E20每个时间点的孕鼠,取E10～E17的胚胎头、E18～E20的胚胎内耳,通过冰冻连续切片、HE染色及免疫荧光观察小鼠内耳前庭末梢器官的形态发育过程及MyosinⅥ抗体标记阳性毛细胞出现的时间。结果小鼠内耳前庭末梢器官发育早、过程短,E10是听囊,E11已经能区分出背侧较大的前庭囊和腹侧较小的耳蜗囊,E12的前庭囊和耳蜗囊区分已很明显,并且出现内淋巴囊和管、上和后半规管始基,E13可见到上和后半规管壶腹嵴始基,出现水平半规管始基和椭圆囊始基,E14形成球囊和水平半规管壶腹嵴始基,E15椭圆囊、球囊、膜半规管初具成熟形态,所有囊斑、壶腹嵴基本形成,E18形态发育基本完成。MyosinⅥ标记阳性表达的毛细胞在E15的所有壶腹嵴、囊斑里出现,未见支持细胞表达MyosinⅥ。结论 MyosinⅥ在E15开始表达,这个时期可能是毛细胞成熟的关键时期。

Objective To explore the morphological development process of periphery vestibular organs in inner ear and expression of myosin VI in C57BL/6 mice.Methods Using embryo heads from E10 to E17 old mice and embryo inner ears from E18 to E20 old mice,the morphological development process of periphery vestibular organs in C57BL/6 mice inner ear and expression of myosin VI in vestibule on different developmental stages were investigated through frozen serial section,HE staining and immunofluorescence assay.Results Vestibular development of mice initiated early and the process was short.Otic capsule arose at E10.The large dorsal vestibular sac(VS) and small ventral cochlear sac(CS) began to form at E11.The differentiation of VS and CS became obvious,and the endolymphatic sac and tube and the superior and posterior semicircular canal primordium arose at E12.The superior and posterior semicircular canal cristae primordium and the lateral semicircular canal and utricle primordium arose at E13.The lateral semicircular canal cristae and saccule primordium arose at E14.The mature structures of utricle,saccule and semicircular canal began to form,and all macula and crista ampullaris formed at E15.The morphological development completed at E18.The myosin VI-positive hair cells were found in all macula and crista ampullaris at E15,but no myosin VI expression was detected in supporting cells.Conclusion Expression of myosin VI begins at E15,which may be a critical period for hair cell maturation.