Baumann O, Murphy D B
Institut für Zoophysiologie und Zellbiologie, Universität Potsdam, Germany.
Cell Motil Cytoskeleton. 1995;32(4):305-17. doi: 10.1002/cm.970320407.
Using video-enhanced differential interference microscopy and digital image processing, we have observed organelle motility in Acanthamoeba castellanii. In amoebae taken from cultures in rapid growth phase, mitochondria and small particles moved over distances of several microns and at an average velocity of approximately 2 microns/s. Mitochondrial motility was verified by intensified fluorescence microscopy of cells that were labeled in vivo with the DNA-binding dye DAPI or the mitochondria-specific dye MitoTracker. We further studied the role of microtubules (MTs) in the translocation of cell organelles. Double-labeling of fixed cells with mitochondrial markers (anti-F1 beta antibody, MitoTracker) and cytoskeletal markers (anti-tubulin antibody, rhodamine-phalloidin) demonstrate that the mitochondria colocalize with MTs in the subcortical cell area and are excluded from the F-actin-rich cell cortex. Colchicine treatment resulted in an almost complete depolymerization of MTs and an inhibition of organelle motility. Moreover, we have directly visualized MTs in vivo in flattened amoebae. Mitochondria and small particles moved along the MTs in a bidirectional mode at an average velocity of approximately 1 micron/s. We conclude that the observed movement of mitochondria and small particles in Acanthamoeba castellanii mainly occurs via microtubules and associated motor proteins.
利用视频增强微分干涉显微镜和数字图像处理技术，我们观察了卡氏棘阿米巴的细胞器运动。在取自快速生长阶段培养物的变形虫中，线粒体和小颗粒移动了数微米的距离，平均速度约为2微米/秒。通过对用DNA结合染料DAPI或线粒体特异性染料MitoTracker进行体内标记的细胞进行增强荧光显微镜观察，验证了线粒体的运动。我们进一步研究了微管（MTs）在细胞器转运中的作用。用线粒体标记物（抗F1β抗体、MitoTracker）和细胞骨架标记物（抗微管蛋白抗体、罗丹明-鬼笔环肽）对固定细胞进行双重标记，结果表明线粒体在皮层下细胞区域与MTs共定位，并且被富含F-肌动蛋白的细胞皮层排除在外。秋水仙碱处理导致MTs几乎完全解聚，并抑制了细胞器运动。此外，我们在扁平变形虫体内直接观察到了MTs。线粒体和小颗粒以双向模式沿着MTs移动，平均速度约为1微米/秒。我们得出结论，在卡氏棘阿米巴中线粒体和小颗粒的观察到的运动主要通过微管和相关的运动蛋白发生。
