Visualization of early chromosome condensation
Visualization of early chromosome condensation
复制标题
早期染色体凝聚的可视化
作者：
N. Kireeva;M. Lakonishok;I. Kireev;T. Hirano;A. Belmont
目前的有丝分裂染色体结构模型主要是基于对最密集的中期染色体的检查。在这里，我们通过将两个支架成分的分布与前期染色体折叠中间体的外观相关联来测试这些模型。我们证实了拓扑异构酶IIα和凝集素亚单位SmC2在未提取的中期染色体中的轴向分布，SmC2定位于直径150-200 nm的中心核心。与径向环/支架模型的预测相反，这种轴向分布直到形成均匀凝聚的中期前期染色体后才出现。相反，SMC2伴随着整个早期和中期的染色单体，经常在染色体外部形成焦点。早期凝聚是通过将大量染色质纤维折叠成凝集团而发生的。这些分裂成线形，直径200-300 nm的中期前期染色单体，其直径在后期前期加倍。我们提出了一个染色体结构的统一模型，在这个模型中，染色质折叠的层次水平在有丝分裂后期通过轴向“胶水”稳定下来。
Current models of mitotic chromosome structure are based largely on the examination of maximally condensed metaphase chromosomes. Here, we test these models by correlating the distribution of two scaffold components with the appearance of prophase chromosome folding intermediates. We confirm an axial distribution of topoisomerase IIα and the condensin subunit, structural maintenance of chromosomes 2 (SMC2), in unextracted metaphase chromosomes, with SMC2 localizing to a 150–200-nm-diameter central core. In contrast to predictions of radial loop/scaffold models, this axial distribution does not appear until late prophase, after formation of uniformly condensed middle prophase chromosomes. Instead, SMC2 associates throughout early and middle prophase chromatids, frequently forming foci over the chromosome exterior. Early prophase condensation occurs through folding of large-scale chromatin fibers into condensed masses. These resolve into linear, 200–300-nm-diameter middle prophase chromatids that double in diameter by late prophase. We propose a unified model of chromosome structure in which hierarchical levels of chromatin folding are stabilized late in mitosis by an axial “glue.”
影响因子：
10.5
作者：
Hagstrom, KA;Holmes, VF;Meyer, BJ
通讯作者：
Meyer, BJ
使用电子显微镜免疫细胞化学和银增强 1.4 nm 金颗粒将 GAD 定位在小脑核中。
DOI：
10.1177/43.3.7868863
发表时间：
1995
期刊：
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
影响因子：
--
作者：
Gilerovitch,HG;Bishop,GA;King,JS;Burry,RW
通讯作者：
Burry,RW
核超微结构：透射电子显微镜和图像分析。
影响因子：
--
作者：
Belmont,AS
通讯作者：
Belmont,AS