Zatsepina O V, Polyakov V Y, Chentsov Y S
A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, USSR.
Chromosoma. 1989 Aug;98(2):109-116. doi: 10.1007/BF00291046.
The chromosomal ultrastructure of Chinese hamster cells treated with 0.075 M KCl - a solution ordinarily used for making preparations of spread chromosomes - was studied. The hypotonic treatment was shown to result in differential decondensation of chromosomes which consists in the uneven distribution of deoxyribonucleoprotein (DNP) fibrils along chromatids. Fixation of cells with methanol acetic acid causes an abrupt restructuring of chromosomes. However, the DNP preserves its uneven distribution along chromatids. As seen on ultra-thin sections of marker nucleolus organizer chromosomes, the densely packed regions may correspond to G-bands detected in the selfsame chromosomes by standard methods of differential staining. The results suggest that the capacity of chromosomes for differential staining is based on the different resistance of G- and R-bands to the decondensing action of hypotonic solutions on living cells.
研究了用0.075M KCl（一种通常用于制备伸展染色体标本的溶液）处理的中国仓鼠细胞的染色体超微结构。结果表明，低渗处理导致染色体的差异性解聚，其表现为脱氧核糖核蛋白（DNP）纤维沿染色单体分布不均。用甲醇乙酸固定细胞会导致染色体的突然重组。然而，DNP沿染色单体仍保持其不均匀分布。在标记核仁组织区染色体的超薄切片上可以看到，紧密堆积的区域可能对应于用标准差异染色方法在同一染色体上检测到的G带。结果表明，染色体进行差异染色的能力基于G带和R带对低渗溶液对活细胞解聚作用的不同抗性。
