Mougneau E, Birg F, Rassoulzadegan M, Cuzin F
Cell. 1980 Dec;22(3):917-27. doi: 10.1016/0092-8674(80)90569-3.
The state and organization of viral DNA sequences present in independently isolated rat cell lines transformed with SV40 were investigated using restriction-enzyme cleavage of the cellular DNA and blot hybridization with a viral probe. The transformed lines were established under conditions as identical as possible, except for a limited number of variables (multiplicity of infection, physiological state of the cells after infection and procedures used for selecting the transformed derivatives). They were characterized after a limited number of generations in culture. Two distinct types of organization were found: covalently integrated viral genomes were present either as single inserts or as head-to-tail oligomeric structures. The latter was observed among transformants derived from cells maintained after infection under growth-inhibiting conditions (suspension in agarose medium, confluency on a solid substrate). Single inserts were observed only among cell lines isolated after an initial period of active growth. Recurrent patterns of hybridizaton were observed in independently isolated lines, indicating that the sites of the integrative recombinations were close enough, both in the viral and the cellular sequences, not to be distinguished at the level of sensitivity of the technique (more than +/- 100 bp). Among cell lines with multiple integration sites, only part of the inserts were found in several instances to be identical to inserts observed in other transformed lines.
利用细胞DNA的限制性酶切和病毒探针的印迹杂交技术，对用SV40转化的独立分离的大鼠细胞系中存在的病毒DNA序列的状态和组织进行了研究。除了有限数量的变量（感染复数、感染后细胞的生理状态以及用于选择转化衍生物的程序）外，在尽可能相同的条件下建立了转化细胞系。在培养有限代数后对它们进行了表征。发现了两种不同类型的组织：共价整合的病毒基因组以单插入片段或头对头寡聚结构的形式存在。在源自感染后在生长抑制条件下维持的细胞（琼脂糖培养基中的悬浮液、固体底物上的汇合）的转化体中观察到了后者。仅在活跃生长的初始阶段后分离的细胞系中观察到单插入片段。在独立分离的细胞系中观察到了重复的杂交模式，这表明在病毒和细胞序列中，整合重组的位点足够接近，以至于在该技术的灵敏度水平（超过+/-100 bp）上无法区分。在具有多个整合位点的细胞系中，在某些情况下仅发现部分插入片段与在其他转化细胞系中观察到的插入片段相同。
