Interpolar spindle microtubules in PTK cells.
Interpolar spindle microtubules in PTK cells.
复制标题
PTK细胞中极线纺锤微管。
DOI：
10.1083/jcb.123.6.1475
复制
发表时间：
1993-12
影响因子：
7.8
通讯作者：
McIntosh, J R
中科院分区：
文献类型：
--
作者：
Mastronarde, D N;McDonald, K L;Ding, R;McIntosh, J R
纺锤体微管（MTs）在PtK 1细胞，固定在从中期到末期的阶段，已重建使用连续切片，电子显微镜和计算机图像处理。我们已经研究了类的MT，形成一个相互交错的系统连接的两个主轴极（极间MT或ipMT）和他们的关系，主轴MT附加到着丝粒（KMT）。从横截面上看，在整个有丝分裂过程中，ipMT与反平行的近邻聚集在一起;随着后期的进行，这种捆绑变得更加明显。虽然大多数kMT的负端靠近极点，但ipMT的负端分布在主轴长度的一半上，其中至少50%位于距极点> 1.5微米处。ipMT束的纵向视图显示了中期和后期B之间它们的正端的主要重排。然而，这些MT的负端并没有明显地远离纺锤体中平面移动，这表明这些MT的滑动对后期B的贡献很小。在整个后期A，ipMT的负端明显地聚集在kMT束中。这些末端靠近kMT的频率比偶然预期的要高得多，这表明了一种特定的相互作用。随着姐妹动粒分离和kMT缩短，kMT的负端保持与纺锤体极相关联，但许多ipMT的负端从kMT束释放，允许纺锤体极和kMT随着纺锤体伸长而远离ipMT移动。
Spindle microtubules (MTs) in PtK1 cells, fixed at stages from metaphase to telophase, have been reconstructed using serial sections, electron microscopy, and computer image processing. We have studied the class of MTs that form an interdigitating system connecting the two spindle poles (interpolar MTs or ipMTs) and their relationship to the spindle MTs that attach to kinetochores (kMTs). Viewed in cross section, the ipMTs cluster with antiparallel near neighbors throughout mitosis; this bundling becomes much more pronounced as anaphase proceeds. While the minus ends of most kMTs are near the poles, those of the ipMTs are spread over half of the spindle length, with at least 50% lying > 1.5 microns from the poles. Longitudinal views of the ipMT bundles demonstrate a major rearrangement of their plus ends between mid- and late anaphase B. However, the minus ends of these MTs do not move appreciably farther from the spindle midplane, suggesting that sliding of these MTs contributes little to anaphase B. The minus ends of ipMTs are markedly clustered in the bundles of kMTs throughout anaphase A. These ends lie close to kMTs much more frequently than would be expected by chance, suggesting a specific interaction. As sister kinetochores separate and kMTs shorten, the minus ends of the kMTs remain associated with the spindle poles, but the minus ends of many ipMTs are released from the kMT bundles, allowing the spindle pole and the kMTs to move away from the ipMTs as the spindle elongates.