Institut Pasteur, Trypanosome Cell Biology Unit, Paris, France.
Cell Microbiol. 2011 May;13(5):705-16. doi: 10.1111/j.1462-5822.2010.01566.x. Epub 2011 Jan 18.
African trypanosomes are flagellated protozoan parasites responsible for sleeping sickness and transmitted by tsetse flies. The accomplishment of their parasite cycle requires adaptation to highly diverse environments. These transitions take place in a strictly defined order and are accompanied by spectacular morphological modifications in cell size, shape and positioning of organelles. To understand the molecular bases of these processes, parasites isolated from different tissues of the tsetse fly were analysed by immunofluorescence with markers for specific cytoskeleton components and by a new immunofluorescence-based assay for evaluation of the cell volume. The data revealed striking differences between proliferative stages found in the midgut or in the salivary glands and the differentiating stage occurring in the proventriculus. Cell proliferation was characterized by a significant increase in cell volume, by a pronounced cell elongation marked by microtubule extension at the posterior end, and by the production of a new flagellum similar to the existing one. In contrast, the differentiating stage found in the proventriculus does not display any increase in cell volume neither in cell length, but is marked by a profound remodelling of the posterior part of the cytoskeleton and by changes in molecular composition and/or organization of the flagellum attachment zone.
非洲锥虫是一种有鞭毛的原生动物寄生虫，可引起昏睡病，并通过采采蝇传播。寄生虫周期的完成需要适应高度多样化的环境。这些转变按严格规定的顺序进行，并伴随着细胞大小、形状和细胞器定位的显著形态变化。为了了解这些过程的分子基础，我们用针对特定细胞骨架成分的标记物对从采采蝇不同组织中分离出来的寄生虫进行免疫荧光分析，并通过一种新的基于免疫荧光的方法评估细胞体积。数据显示，在中肠或唾液腺中发现的增殖阶段与在前胃中发生的分化阶段之间存在显著差异。细胞增殖的特征是细胞体积显著增加，由微管在后端延伸标记的明显细胞伸长，以及产生类似于现有鞭毛的新鞭毛。相比之下，在前胃中发现的分化阶段既不会增加细胞体积，也不会增加细胞长度，但以细胞骨架后部的深刻重塑为特征，并伴有鞭毛附着区的分子组成和/或组织的变化。
