Satir Peter, Mitchell David R, Jékely Gáspár
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, USA.
Curr Top Dev Biol. 2008;85:63-82. doi: 10.1016/S0070-2153(08)00803-X.
The cilium is a characteristic organelle of eukaryotes constructed from over 600 proteins. Bacterial flagella are entirely different. 9 + 2 motile cilia evolved before the divergence of the last eukaryotic common ancestor (LECA). This chapter explores, compares, and contrasts two potential pathways of evolution: (1) via invasion of a centriolar-like virus and (2) via autogenous formation from a pre-existing microtubule-organizing center (MTOC). In either case, the intraflagellar transport (IFT) machinery that is nearly universally required for the assembly and maintenance of cilia derived from the evolving intracellular vesicular transport system. The sensory function of cilia evolved first and the ciliary axoneme evolved gradually with ciliary motility, an important selection mechanism, as one of the driving forces.
纤毛是由600多种蛋白质构成的真核生物特有的细胞器。细菌鞭毛则完全不同。9+2运动性纤毛在最后一个真核生物共同祖先（LECA）分化之前就已进化出来。本章探讨、比较并对比了两种潜在的进化途径：（1）通过类似中心粒的病毒入侵，以及（2）通过由预先存在的微管组织中心（MTOC）自发形成。在任何一种情况下，纤毛组装和维持几乎普遍需要的鞭毛内运输（IFT）机制都源自不断进化的细胞内囊泡运输系统。纤毛的感觉功能首先进化出来，而纤毛轴丝随着纤毛运动性逐渐进化，纤毛运动性作为一种重要的选择机制，是驱动力之一。
