Nichols B A, Chiappino M L
J Protozool. 1987 May;34(2):217-26. doi: 10.1111/j.1550-7408.1987.tb03162.x.
The cytoskeleton of Toxoplasma gondii was studied by electron microscopy using whole mounts of detergent-extracted parasites and thin sections of routine preparations, tannic acid-stained organisms, and detergent-extracted parasites. In whole mounts, the spiral arrangement of the 22 pellicular microtubules closely corresponded to the pattern of surface ridges seen previously by scanning electron microscopy and reflected the torsion of the parasite body during locomotion. The microtubules had free posterior ends and were anchored anteriorly in the polar ring, presumed to be a microtubule organizing center (MTOC). The insertions of the microtubules were supported by blunt projections of the polar ring, forming a cogwheel pattern in transverse view. The internal microtubules had 13 protofilaments and were twice the length of the conoid. They extended through the conoid and ended at the anterior preconoidal ring, presumably a second MTOC. The subunits of the conoid were arranged in a counterclockwise spiral when traced from base to tip, as were the pellicular microtubules. We postulate that as the conoid moves, the polar ring complex moves along the spiral pathway of the conoid subunits. Retraction of the conoid would then rotate the polar ring, producing the torsion of the body we observed by SEM.
利用去污剂处理后的寄生虫整装标本、常规制备的薄切片、经单宁酸染色的生物体以及去污剂处理后的寄生虫，通过电子显微镜对刚地弓形虫的细胞骨架进行了研究。在整装标本中，22条表膜微管的螺旋排列与先前扫描电子显微镜观察到的表面嵴的模式紧密对应，反映了寄生虫在运动过程中身体的扭转。微管后端游离，前端锚定在极环中，极环被认为是一个微管组织中心（MTOC）。微管的插入由极环的钝性突起支撑，在横切面上形成齿轮状模式。内部微管有13条原纤维，长度是锥体的两倍。它们穿过锥体并终止于前锥体前环，推测这是第二个微管组织中心。从基部到顶端追踪时，锥体的亚基呈逆时针螺旋排列，表膜微管也是如此。我们推测，随着锥体移动，极环复合体沿着锥体亚基的螺旋路径移动。然后锥体的缩回会使极环旋转，产生我们通过扫描电子显微镜观察到的身体扭转。
