Earnshaw W C, Heck M M
J Cell Biol. 1985 May;100(5):1716-25. doi: 10.1083/jcb.100.5.1716.
In the preceding article we described a polyclonal antibody that recognizes cSc-1, a major polypeptide component of the chicken mitotic chromosome scaffold. This polypeptide was shown to be chicken topoisomerase II. In the experiments described in the present article we use indirect immunofluorescence and immunoelectron microscopy to examine the distribution of topoisomerase II within intact chromosomes. We also describe a simple experimental protocol that differentiates antigens that are interspersed along the chromatin fiber from those that occupy restricted domains within the chromosome. These experiments indicate that the distribution of the enzyme appears to be independent of the bulk chromatin. Our data suggest that topoisomerase II is bound to the bases of the radial loop domains of mitotic chromosomes.
在前一篇文章中，我们描述了一种识别cSc-1的多克隆抗体，cSc-1是鸡有丝分裂染色体支架的主要多肽成分。该多肽被证明是鸡拓扑异构酶II。在本文所述的实验中，我们使用间接免疫荧光和免疫电子显微镜来检查拓扑异构酶II在完整染色体内的分布。我们还描述了一个简单的实验方案，该方案可区分沿染色质纤维散布的抗原与占据染色体内受限区域的抗原。这些实验表明，该酶的分布似乎与整体染色质无关。我们的数据表明，拓扑异构酶II与有丝分裂染色体的放射状环结构域的基部结合。
