Cande W Z, Lazarides E, McIntosh J R
J Cell Biol. 1977 Mar;72(3):552-67. doi: 10.1083/jcb.72.3.552.
Rabbit antibodies against actin and tubulin were used in an indirect immunofluorescence study of the structure of the mitotic spindle of PtK1 cells after lysis under conditions that preserve anaphase chromosome movement. During early prophase there is no antiactin staining associated with the mitotic centers, but by late prophase, as the spindle is beginning to form, a small ball of actin antigenicity is found beside the nucleus; After nuclear envelope breakdown, the actiactin stains the region around each mitotic center, and becomes organized into fibers that run between the chromosomes and the poles. Colchicine blocks this organization, but does not disrupt the staining at the poles. At metaphase the antiactin reveals a halo of ill-defined radius around each spindle pole and fibers that run from the poles to the metaphase plate. Antitubulin shows astral rays, fibers running from chromosomes to poles, and some fibers that run across the metaphase plate. At anaphase, there is a shortening of the antiactin-stained fibers, leaving a zone which is essentially free of actin-staining fluorescence between the separating chromosomes. Antitubulin stains the region between chromosomes and poles, but also reveals substantial fibers running through the zone between separating chromosomes. Cells fixed during cytokinesis show actin in the region of the cleavage furrow, while antitubulin reveals the fibrous spindle remnant that runs between daughter cells. These results suggest that actin is a component of the mammalian mitotic spindle, that the distribution of actin differs from that of tubulin and that the distributions of these two fibrous proteins change in different ways during anaphase.
在能保持后期染色体运动的裂解条件下，利用抗肌动蛋白和抗微管蛋白的兔抗体对PtK1细胞有丝分裂纺锤体结构进行间接免疫荧光研究。在前期早期，与有丝分裂中心没有抗肌动蛋白染色相关，但到前期后期，随着纺锤体开始形成，在细胞核旁发现一小团肌动蛋白抗原性物质；核膜破裂后，肌动蛋白对每个有丝分裂中心周围区域进行染色，并组织成在染色体和两极之间延伸的纤维。秋水仙碱阻止这种组织形成，但不破坏两极的染色。在中期，抗肌动蛋白显示每个纺锤体极周围有一个半径不明确的晕圈以及从极延伸到中期板的纤维。抗微管蛋白显示星体射线、从染色体延伸到极的纤维以及一些穿过中期板的纤维。在后期，抗肌动蛋白染色的纤维缩短，在分离的染色体之间留下一个基本上没有肌动蛋白染色荧光的区域。抗微管蛋白对染色体和极之间的区域进行染色，但也显示有大量纤维穿过分离染色体之间的区域。在胞质分裂期间固定的细胞在分裂沟区域显示有肌动蛋白，而抗微管蛋白显示在子细胞之间延伸的纤维状纺锤体残余物。这些结果表明肌动蛋白是哺乳动物有丝分裂纺锤体的一个组成部分，肌动蛋白的分布与微管蛋白不同，并且这两种纤维蛋白的分布在后期以不同方式发生变化。
