Outka D E, Kluss B C
J Cell Biol. 1967 Nov;35(2):323-46. doi: 10.1083/jcb.35.2.323.
Tetramitus exhibits independent ameboid and flagellate stages of remarkable morphological dichotomy. Transformation of the ameba involves the formation of four kinetosomes and their flagella. The arrangement of these kinetosomes and associated whorls of microtubules extending under the pellicle establishes the asymmetric flagellate form. While no recognizable kinetosomal precursors have been seen in amebae, and there is no suggestion of self-replication in dividing flagellates, developmental stages of kinetosomes have been identified. These are occasionally seen in association with the nucleus or with dense bodies which lie either inside of or close to the proximal end of the prokinetosome. Outgrowth of flagella involves formation of an axoneme and a membrane. From the distal tip of the kinetosome microtubules grow into a short bud, which soon forms an expanded balloon containing a reticulum of finely beaded filaments. The free ends of the microtubules appear unraveled; they are seen first as single elements, then as doublets, and finally are arranged into a cylinder. Growth in length is accompanied by a reduction in the diameter of the balloon. The concept that the formation of the kinetic apparatus might involve a nuclear contribution, followed by a spontaneous assembly of microtubules, is suggested.
四鞭毛虫呈现出独立的变形虫阶段和鞭毛虫阶段，形态差异显著。变形虫的转变涉及四个动基体及其鞭毛的形成。这些动基体以及在表膜下延伸的相关微管环的排列确立了不对称的鞭毛虫形态。虽然在变形虫中未观察到可识别的动基体前体，并且在分裂的鞭毛虫中也没有自我复制的迹象，但已确定了动基体的发育阶段。这些阶段偶尔会与细胞核或位于原动基体近端内部或附近的致密体相关联。鞭毛的生长涉及轴丝和膜的形成。从动基体的远端，微管生长成一个短芽，很快形成一个膨胀的球囊，其中含有由细珠状细丝组成的网状结构。微管的自由端似乎解开了；首先看到它们是单个元素，然后是双联体，最后排列成一个圆柱体。长度的增长伴随着球囊直径的减小。这表明动基体形成过程可能涉及细胞核的作用，随后是微管的自发组装。
