小鼠耳蜗胚胎发育过程中Smad4基因的表达  

Expression of Smad4 in the embryonic development of the mouse inner ear

作　　者：宇雅苹[1] 杨仕明[1] 胡吟燕[1] 郭维[1] 孙建和[1] 于宁[1] 韩东一[1] 杨伟炎[1] 

机构地区：[1]解放军耳鼻咽喉研究所解放军总医院耳鼻咽喉头颈外科,北京100853

出　　处：《中华耳科学杂志》2006年第3期164-167,共4页Chinese Journal of Otology

基　　金：国家自然科学基金(30571017;30000189);军队"十五"科研基金(01Q050);北京市自然科学基金(7042061)资助

摘　　要：目的探讨小鼠内耳胚胎发育演变过程,检测Smad4基因在小鼠耳蜗中的表达情况。方法选用耳廓反应灵敏、健康的C57BL/6小鼠作为种鼠交配,用观察阴栓方法获得适龄胎鼠,≤17天取胚胎头,≥18天在显微镜下取耳蜗,胚胎头水平冰冻切片,耳蜗平行于蜗轴冰冻切片,HE染色方法观察小鼠耳蜗发育形态演变过程,免疫组织化学方法检测Smad4蛋白在小鼠胚胎10～20天耳蜗中的表达情况。结果胚胎10天,听泡发育,胚胎12天听泡下部有蜗管始基形成并开始发育。胚胎18天,蜗管发育2圈,形成了可以辨认的内、外毛细胞,血管纹开始分化。Smad4从胚胎15天才开始表达,最初表达部位为耳蜗底转将发育成蜗轴以及柱状上皮分化为感觉细胞及支持细胞的区域,但在胚胎早期表达较弱,后期在耳蜗内广泛表达,在螺旋器、血管纹、前庭膜均有表达,且表达逐渐增强,而在蜗轴部位的表达逐渐减弱。结论Smad4在小鼠内耳分化期有阳性表达,且表达具有明显的阶段性和区域性,说明其参与内耳听觉器官的发育过程并且可能在耳蜗的形成过程中起着重要的作用。Objective To explore the developmental process of the embryonic mouse inner ear and to investigate whether Smad4 is expressed in the embryonic mouse cochlea. Methods The inner ears were obtained from C57BL/6 mice at ages ranging from gestational day 10 through day 20. Gestational age was determined by the vaginal plug technique （E1= day of the vaginal plug）. Frozen sections 6μm in thickness for embryos were processed for HE staining to observe morphological changes of the embryonic mouse cochlea and for immunohistochemistry to determine the expression of Smad4. Results At the tenth day gestation otocyst was a closed ovoid sac. The cochlear duct started to develop at the twelfth day of gestation as an extension of the ventral part of the otocyst. At the eighteenth day the inner hair cells and outer hair cells were identified. The Smad4 gene was expressed in cochlea from El5. At first, it was expressed in the parts which should develop into the cochlear axes, sensory cells and supporting cells. Then smad4 expression was concentrated in supporting cells, hair cells, spiral ganglions and epithelia of the stria vascularis during a later stage. Conclusion The Smad4 proteins exist in the embryonic mouse cochlea and it may be involved in the cochlear formation. Smad4 might be an essential factor for the development of the mouse cochlea.

关 键 词：内耳 发育 耳蜗 小鼠 SMAD4 

分 类 号：Q394.11[生物学—遗传学] R321.59[医药卫生—人体解剖和组织胚胎学]