Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853, USA.
Dev Dyn. 2011 Nov;240(11):2405-31. doi: 10.1002/dvdy.22756.
Two positional characteristics of the ciliary axoneme--its location on the plasma membrane as it emerges from the cell, and its orientation in three-dimensional (3D) space--are known to be critical for optimal function of actively motile cilia (including nodal cilia), as well as for modified cilia associated with special senses. However, these positional characteristics have not been analyzed to any significant extent for primary cilia. This review briefly summarizes the history of knowledge of these two positional characteristics across a wide spectrum of cilia, emphasizing their importance for proper function. Then the review focuses what is known about these same positional characteristics for primary cilia in all major tissue types where they have been reported. The review emphasizes major areas that would be productive for future research for understanding how positioning and 3D orientation of primary cilia may be related to their hypothesized signaling roles within different cellular populations.
纤毛轴丝的两个位置特征——其从细胞中伸出时在质膜上的位置和在三维（3D）空间中的取向——已知对活跃运动纤毛（包括 nodal 纤毛）的最佳功能以及与特殊感觉相关的修饰纤毛至关重要。然而，对于初级纤毛，这些位置特征尚未进行任何重要程度的分析。本综述简要总结了跨越广泛纤毛范围的这两个位置特征的知识历史，强调了它们对正常功能的重要性。然后，综述重点介绍了在已报道的所有主要组织类型中，初级纤毛的这些相同位置特征的已知情况。该综述强调了未来研究的重要领域，以了解初级纤毛的定位和 3D 取向如何与其在不同细胞群中的假设信号作用相关。
