Kinetochore microtubules in PTK cells.
Kinetochore microtubules in PTK cells.
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DOI：
10.1083/jcb.118.2.369
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发表时间：
1992-07
期刊：
影响因子：
--
通讯作者：
McIntosh JR
中科院分区：
文献类型：
--
作者：
McDonald KL;O'Toole ET;Mastronarde DN;McIntosh JR
我们使用连续薄片电子显微镜和计算机图像处理来跟踪微管（MT）成分在三个维度的轨迹，分析了 PtK1 细胞中期和后期有丝分裂纺锤体的 10 条染色体纤维的精细结构。大多数动粒 MT 从动粒延伸到极点附近，在整个长度上保持簇状排列。该 MT 束被大量与动粒无关的其他 MT 侵入。入侵的 MT 经常靠近着丝粒 MT，但相邻密度的二维分析未能识别出两个 MT 类别之间的任何特征间距。与带间 MT 邻近密度分析的结果不同，动粒 MT 和其他纺锤体 MT 之间的间距分布没有显示出强 MT-MT 相互作用的证据。然而，对着丝粒 MT 与其他纺锤体 MT 之间最接近距离的三维分析表明，最常见的最近接近距离为 30-50 nm，这表明着丝粒 MT 与其邻居之间的相互作用较弱。这些数据支持这样的观点：着丝粒 MT 在着丝粒和定义极点的中心粒周围材料之间形成机械连接，但着丝粒 MT 和其他纺锤体 MT 之间的机械相互作用较弱。
We have analyzed the fine structure of 10 chromosomal fibers from mitotic spindles of PtK1 cells in metaphase and anaphase, using electron microscopy of serial thin sections and computer image processing to follow the trajectories of the component microtubules (MTs) in three dimensions. Most of the kinetochore MTs ran from their kinetochore to the vicinity of the pole, retaining a clustered arrangement over their entire length. This MT bundle was invaded by large numbers of other MTs that were not associated with kinetochores. The invading MTs frequently came close to the kinetochore MTs, but a two-dimensional analysis of neighbor density failed to identify any characteristic spacing between the two MT classes. Unlike the results from neighbor density analyses of interzone MTs, the distributions of spacings between kinetochore MTs and other spindle MTs revealed no evidence for strong MT-MT interactions. A three-dimensional analysis of distances of closest approach between kinetochore MTs and other spindle MTs has, however, shown that the most common distances of closest approach were 30-50 nm, suggesting a weak interaction between kinetochore MTs and their neighbors. The data support the ideas that kinetochore MTs form a mechanical connection between the kinetochore and the pericentriolar material that defines the pole, but that the mechanical interactions between kinetochore MTs and other spindle MTs are weak.