Cell migration, intercalation and growth regulate mammalian cochlear extension
Cell migration, intercalation and growth regulate mammalian cochlear extension
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DOI：
10.1242/dev.151761
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发表时间：
2017-10-15
期刊：
影响因子：
4.6
通讯作者：
Kelley, Matthew W.
中科院分区：
文献类型：
--
作者：
Driver, Elizabeth Carroll;Northrop, Amy;Kelley, Matthew W.
耳蜗感觉上皮的发育重塑是形成一个细长的、有张力的听觉器官所必需的，但介导这些事件的细胞过程在很大程度上是未知的。我们使用细胞重排的形态学评估和延时成像来观察小鼠耳蜗重构。细胞重分布分析表明，耳蜗的扩展是通过径向插层和细胞生长的结合进行的。实时成像显示，伴随的细胞嵌入导致短暂的上皮聚集，尽管随后细胞大小的变化导致内侧-外侧扩散。与基底膜保持接触的支持细胞表现出偏向的突出活动和沿延伸轴的定向运动。相比之下，毛细胞失去了与基底膜的接触，但通过增加细胞大小来促进持续的生长。耳蜗内细胞突起、运动和嵌入的调节都需要肌球蛋白II。这些结果首次确立了驱动感觉细胞沿耳蜗张力轴分布的许多细胞过程。
Developmental remodeling of the sensory epithelium of the cochlea is required for the formation of an elongated, tonotopically organized auditory organ, but the cellular processes that mediate these events are largely unknown. We used both morphological assessments of cellular rearrangements and time-lapse imaging to visualize cochlear remodeling in mouse. Analysis of cell redistribution showed that the cochlea extends through a combination of radial intercalation and cell growth. Live imaging demonstrated that concomitant cellular intercalation results in a brief period of epithelial convergence, although subsequent changes in cell size lead to medial-lateral spreading. Supporting cells, which retain contact with the basement membrane, exhibit biased protrusive activity and directed movement along the axis of extension. By contrast, hair cells lose contact with the basement membrane, but contribute to continued outgrowth through increased cell size. Regulation of cellular protrusions, movement and intercalation within the cochlea all require myosin II. These results establish, for the first time, many of the cellular processes that drive the distribution of sensory cells along the tonotopic axis of the cochlea.