Ultrastructural evidence for an unusual mode of ciliogenesis in mouse multiciliated epithelia
Ultrastructural evidence for an unusual mode of ciliogenesis in mouse multiciliated epithelia
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小鼠多纤毛上皮异常纤毛发生模式的超微结构证据
DOI：
10.1093/jmicro/dfaa074
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发表时间：
2020
期刊：
影响因子：
1.8
通讯作者：
Takeda Sen
中科院分区：
文献类型：
--
作者：
Narita Keishi;Takeda Sen
多纤毛发生是在单细胞中产生数百个活动纤毛的级联过程。在脊椎动物中，这一过程已在脑室室管膜以及气道和输卵管的纤毛上皮中进行了研究。尽管扩增中心粒的早期步骤已经在分子细节上得到了表征，但随后建立多纤毛的步骤却相对被忽视了。在这里，我们重点关注先前使用透射电子显微镜在野生型小鼠室管膜中观察到的异常纤毛相关结构，并分析了它们的超微结构特征及其出现频率。室管膜中5%的纤毛呈束状存在；虽然大多数纤毛束是配对的，但也发现了超过三个纤毛束。此外，偶尔观察到含有多组轴丝的顶端突起（每节 0-2 个），表明纤毛发生的不寻常模式。在气管和输卵管上皮中，不存在纤毛束，但观察到含有多个轴丝的突起。在这些突起的底部，某些轴丝完全被膜包裹，而其他轴丝则不完全包裹。这些数据表明，多纤毛发生的后期步骤可能包括纤毛发育的独特过程，该过程与初级纤毛的纤毛发生不同。
Multiciliogenesis is a cascading process for generating hundreds of motile cilia in single cells. In vertebrates, this process has been investigated in the ependyma of brain ventricles and the ciliated epithelia of the airway and oviduct. Although the early steps to amplify centrioles have been characterized in molecular detail, subsequent steps to establish multicilia have been relatively overlooked. Here, we focused on unusual cilia-related structures previously observed in wild-type mouse ependyma using transmission electron microscopy and analyzed their ultrastructural features and the frequency of their occurrence. In the ependyma,5% of cilia existed as bundles; while the majority of the bundles were paired, bundles of more than three cilia were also found. Furthermore, apical protrusions harboring multiple sets of axonemes were occasionally observed (0–2 per section), suggesting an unusual mode of ciliogenesis. In trachea and oviduct epithelia, ciliary bundles were absent, but protrusions containing multiple axonemes were observed. At the base of such protrusions, certain axonemes were completely enwrapped by membranes, whereas others remained incompletely enwrapped. These data suggested that the late steps of multiciliogenesis might include a unique process underlying the development of cilia, which is distinct from the ciliogenesis of primary cilia.