Leitch A R, Brown J K, Mosgöller W, Schwarzacher T, Heslop-Harrison J S
John Innes Centre, Norwich, UK.
Hum Genet. 1994 Mar;93(3):275-80. doi: 10.1007/BF00212022.
Chromosomes from ten human male fibroblast metaphases were completely reconstructed from electron micrographs of serially sectioned material. Chromosome centromere positions were determined by finding the three-dimensional coordinates of the centromere midpoint. The data set showed the identity of nine chromosome types (chromosomes 1, 2, 3, 6, 9, 16, 17, 18 and the Y chromosome) preserved as they are positioned in vivo. The results indicate that there is (1) no significant association of the homologous chromosomes examined, (2) a significant tendency for a central location of the Y chromosome and of chromosome 18, (3) a significant tendency for a peripheral location of chromosome 6, (4) no significant tendency for homologous chromosomes to reorganize as metaphase advances and (5) no significant differential condensation across the metaphase plate. Therefore, the only organization pattern observed for the centromeres of the homologous chromosomes studied is some sorting by size across the metaphase plate. These results may be typical of dividing cell types. Different chromosome arrangements are found in some non-dividing cell types (e.g. mammalian brain cells). The different distributions of chromosomes in different cell types can be considered as forms of "nuclear differentiation". It is postulated that nuclear differentiation may be related to cell differentiation.
从连续切片材料的电子显微照片中，完全重建了来自十个男性人类成纤维细胞中期的染色体。通过确定着丝粒中点的三维坐标来确定染色体着丝粒的位置。数据集显示了九种染色体类型（染色体1、2、3、6、9、16、17、18和Y染色体）在体内定位时保持的一致性。结果表明：（1）所检查的同源染色体之间没有显著关联；（2）Y染色体和18号染色体有显著的位于中央的倾向；（3）6号染色体有显著的位于周边的倾向；（4）随着中期的推进，同源染色体没有显著的重新组织的倾向；（5）在整个中期板上没有显著的差异凝聚。因此，在所研究的同源染色体着丝粒中观察到的唯一组织模式是在中期板上按大小进行某种分类。这些结果可能是分裂细胞类型的典型特征。在一些非分裂细胞类型（如哺乳动物脑细胞）中发现了不同的染色体排列。不同细胞类型中染色体的不同分布可被视为“核分化”的形式。据推测，核分化可能与细胞分化有关。
