Katayama A, Corwin J T
Department of Zoology, University of Hawaii, Honolulu 96822.
J Comp Neurol. 1989 Mar 1;281(1):129-35. doi: 10.1002/cne.902810110.
In the chicken cochlea, the structural features of the cilia bundles of individual hair cells vary systematically along the length of the sensory epithelium. As a first approach to understanding the developmental mechanisms that underlie this precise arrangement of structurally distinct hair cells, the spatiotemporal pattern of the terminal mitoses of their precursor cells was investigated by administering 3H-thymidine, a radioactive precursor to DNA. This demonstrated that the first hair cells were produced during the sixth day of incubation and formed a longitudinal band that extended along most of the length of the sensory epithelium. The epithelium grew further through appositional addition of hair cells at the edges of this first band of cells, and the hair cell addition process expanded into the surrounding areas during the next 3 days. By the ninth day of incubation all the hair cells in the sensory epithelium except for those at the peripheral edges in the distal (apex) portion had been produced through terminal mitoses. Our results have demonstrated that hair cells that have similar stereocilia phenotypes do not all leave the mitotic cycle at the same time.
在鸡的耳蜗中，单个毛细胞的纤毛束结构特征沿感觉上皮的长度呈系统性变化。作为理解这种结构不同的毛细胞精确排列背后发育机制的第一步，通过给予3H-胸腺嘧啶核苷（一种DNA的放射性前体）来研究其前体细胞终末有丝分裂的时空模式。这表明第一批毛细胞在孵化的第6天产生，并形成了一条沿感觉上皮大部分长度延伸的纵向带。上皮通过在这条第一批细胞带的边缘附加毛细胞而进一步生长，并且在接下来的3天里，毛细胞附加过程扩展到周围区域。到孵化的第9天，感觉上皮中除了远端（顶端）部分周边边缘的那些毛细胞外，所有毛细胞都通过终末有丝分裂产生。我们的结果表明，具有相似静纤毛表型的毛细胞并非都在同一时间退出有丝分裂周期。
