Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, D.F., Mexico.
FEMS Microbiol Lett. 2010 Dec;313(1):41-6. doi: 10.1111/j.1574-6968.2010.02117.x. Epub 2010 Sep 29.
Our group is interested in rRNA and ribosome biogenesis in the parasitic protozoan Trypanosoma cruzi. Epimastigotes represent an extracellular replicative stage of T. cruzi and can be cultured in axenic media. The growth curve of epimastigotes allows assessment of potential differences in the nucleoli of cells undergoing growth-rate transitions. To establish cellular parameters for studying ribosome biogenesis in T. cruzi, a morphometric analysis of the nucleoli of cultured cells in the exponential and stationary phases was conducted. Electron micrograph-based measurements of nuclear sections from independent cells demonstrated that the nucleolar area is over twofold higher in exponentially growing cells, as compared with epimastigotes in the stationary phase. The granular component of the nucleoli of actively growing cells was the main structural element. Cycloheximide moderately reduced the apparent size of the nucleoli without an apparent disruption of their architecture. Our results provide a firm basis for the establishment of an experimental model to study the organization of the nucleolus during the growth and development of T. cruzi.
我们的研究小组对寄生原生动物克氏锥虫的 rRNA 和核糖体生物发生感兴趣。滋养体代表克氏锥虫的一种细胞外复制阶段，可以在无细胞培养基中培养。滋养体的生长曲线允许评估处于生长速率转变中的细胞的核仁的潜在差异。为了建立研究克氏锥虫核糖体生物发生的细胞参数，对指数生长期和静止期培养细胞的核仁进行了形态计量分析。来自独立细胞的核切片的基于电子显微镜的测量表明，与静止期的滋养体相比，指数生长期的细胞的核仁面积高两倍以上。活跃生长细胞的核仁颗粒成分是主要的结构元素。细胞松弛素 B 适度减小了核仁的表观大小，而没有明显破坏其结构。我们的结果为建立一个实验模型来研究克氏锥虫生长和发育过程中核仁的组织提供了坚实的基础。
