Katinka M
Biochimie. 1984 Nov-Dec;66(11-12):681-91. doi: 10.1016/0300-9084(84)90257-8.
Two defective polyoma virus genomes, deleted in the nucleotide sequences coding the N-termini of the tumor antigens, were introduced into Fisher 3T3 rat cells by DNA-mediated gene transfer (transfection). The resulting integrated genomes were incapable of conferring a transformed phenotype to the cells. However, after transfection of these lines with small polyoma fragments overlapping the deleted sequences, transformed clones were isolated. These clones were analyzed by Southern genomic blot hybridization and by isolation in E. coli of plasmids containing viral sequences excised following fusion with mouse polyoma growth-permissive cells. In all cases at least one intact copy of the early region of the polyoma genome was found. Furthermore, restriction sites adjacent to the initial inactive insertion remained unchanged in many of the transformed lines. These results show that functional restoration of the defective polyoma early region involves homologous recombination between the deleted viral genomes integrated in the cellular DNA and the transfecting viral fragments.
通过DNA介导的基因转移（转染），将两个在编码肿瘤抗原N端的核苷酸序列中缺失的有缺陷的多瘤病毒基因组导入Fisher 3T3大鼠细胞。所得的整合基因组无法赋予细胞转化表型。然而，在用与缺失序列重叠的小多瘤片段转染这些细胞系后，分离出了转化克隆。通过Southern基因组印迹杂交以及在大肠杆菌中分离含有与小鼠多瘤生长允许细胞融合后切除的病毒序列的质粒，对这些克隆进行了分析。在所有情况下，都发现了至少一个完整的多瘤病毒基因组早期区域拷贝。此外，在许多转化细胞系中，与最初无活性插入相邻的限制性酶切位点保持不变。这些结果表明，有缺陷的多瘤病毒早期区域的功能恢复涉及整合在细胞DNA中的缺失病毒基因组与转染的病毒片段之间的同源重组。
