Hoshi Osamu, Ushiki Tatsuo
Division of Microscopic Anatomy and Bio-imaging, Niigata University Graduate School of Medical and Dental Science, Niigata, Japan.
Arch Histol Cytol. 2009;72(4-5):245-9. doi: 10.1679/aohc.72.245.
The relationship between the higher-order structure of human metaphase chromosomes and the distribution of topoisomerase IIα was analyzed by a comparison of atomic force microscope (AFM) and fluorescence microscope images of the same chromosome. AFM imaging of chromosomes in liquid revealed the presence of alternating ridges and grooves on the surfaces of the sister chromatids. In contrast, the fluorescence image of the chromosomes stained with the anti-topoisomerase IIα antibody showed that the fluorescence intensity of topoisomerase IIα was not uniform and that there were alternating strong and weak spots along the chromosome axes. A comparison of the AFM image with a fluorescence microscope image of the same chromosome further demonstrated that ridges and grooves corresponded to strong and weak fluorescence intensities of topoisomerase IIα, respectively. These findings suggest that the distribution of topoisomerase IIα has a close connection with the higher-order structure of human metaphase chromosomes.
通过比较同一染色体的原子力显微镜（AFM）图像和荧光显微镜图像，分析了人类中期染色体的高阶结构与拓扑异构酶IIα分布之间的关系。液体中染色体的AFM成像显示，姐妹染色单体表面存在交替的脊和沟。相比之下，用抗拓扑异构酶IIα抗体染色的染色体荧光图像显示，拓扑异构酶IIα的荧光强度不均匀，沿染色体轴存在交替的强弱斑点。同一染色体的AFM图像与荧光显微镜图像的比较进一步表明，脊和沟分别对应拓扑异构酶IIα的强弱荧光强度。这些发现表明，拓扑异构酶IIα的分布与人类中期染色体的高阶结构密切相关。
