Ijaz Faryal, Ikegami Koji
Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, Japan.
JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, Japan.
Microscopy (Oxf). 2019 Apr 1;68(2):99-110. doi: 10.1093/jmicro/dfy147.
The cilium is a tiny organelle, with a length of 1-10 μm and a diameter of ~200 nm, that projects from the surface of many cells and functions to generate fluid flow and/or sense extracellular signals from the environment. Abnormalities in cilia may cause a broad spectrum of disease, i.e. the so-called ciliopathies. Multiple imaging approaches have been implemented to understand the structure, motion and function of the tiny cilium. In this review, we focus on the microscopic observations and analyses of the dynamic behaviors of both motile cilia and primary cilium. Motile cilia repeat reciprocal motions at 15-25 Hz with a clear asymmetry of effective and recovery strokes. Observing the fast movement of motile cilia requires a high-speed camera with a frame rate of more than 100 fps. The labeling of cilia tips enables the detailed analysis of the asymmetric beating motion of motile cilia. The primary cilium, which is imagined to be 'static,' is also dynamic, i.e. it elongates, shrinks and disassembles, although this behavior is quite slower than that of motile cilia. The specific fluorescent labeling of primary cilium and time-lapse imaging are required to observe and analyze the slow behaviors of the primary cilium. We present some approaches, including some tips for successful procedures, in the successful imaging of the dynamic behaviors of motile cilia and primary cilium.
纤毛是一种微小的细胞器，长度为1 - 10μm，直径约200nm，从许多细胞表面伸出，其功能是产生流体流动和/或感知来自环境的细胞外信号。纤毛异常可能导致多种疾病，即所谓的纤毛病。人们已经采用了多种成像方法来了解微小纤毛的结构、运动和功能。在这篇综述中，我们重点关注对运动性纤毛和初级纤毛动态行为的显微镜观察与分析。运动性纤毛以15 - 25Hz的频率重复往复运动，有效冲程和恢复冲程明显不对称。观察运动性纤毛的快速运动需要帧率超过100fps的高速摄像机。对纤毛尖端进行标记能够详细分析运动性纤毛的不对称摆动运动。初级纤毛虽然被认为是“静止的”，但实际上也是动态的，即它会伸长、收缩和解聚，不过这种行为比运动性纤毛要慢得多。需要对初级纤毛进行特异性荧光标记并进行延时成像，以观察和分析初级纤毛的缓慢行为。我们介绍了一些方法，包括一些成功操作的技巧，用于成功成像运动性纤毛和初级纤毛的动态行为。
