Razin S V, Mantieva V L, Georgiev G P
Nucleic Acids Res. 1979 Nov 24;7(6):1713-35. doi: 10.1093/nar/7.6.1713.
The fragments of DNA attached to protein skeleton of interphase nuclei or metaphase chromosomes were obtained. Both the method involving restriction endonuclease treatment/1,2/and a novel procedure based on mild staphylococcal nuclease digestion were used. In the latter case, DNA fragments remaining bound to nuclei or chromosomes are not enriched in satellite but only in abundant middle repetitive DNA. The shorter the fragments of attached DNA, the higher the content of middle repetitive DNA in the fraction. It has a slightly higher density in a CsCl gradient comparing to the main DNA. The yield of attached DNA, its distribution in a CsCl density gradient, and its renaturation properties are essentially the same for interphase and metaphase chromosomes. The average size of DNA loops was found to be equal to approximately 60 kb for both metaphase chromosomes and interphase nuclei. The conclusion has been drawn that the bulk of attachment sites of DNP fibrils to axial chromosomal structures remains unchanged during the cell cycle.
获得了附着于间期核或中期染色体蛋白质骨架上的DNA片段。使用了涉及限制性内切酶处理的方法[1,2]以及基于温和葡萄球菌核酸酶消化的新方法。在后一种情况下,仍与核或染色体结合的DNA片段中卫星DNA不富集,仅富含丰富的中度重复DNA。附着DNA片段越短,该组分中中度重复DNA的含量越高。与主要DNA相比,其在CsCl梯度中的密度略高。间期染色体和中期染色体的附着DNA产量、其在CsCl密度梯度中的分布及其复性特性基本相同。发现中期染色体和间期核的DNA环平均大小约为60 kb。得出的结论是,在细胞周期中,DNP纤维与轴向染色体结构的大部分附着位点保持不变。