期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：15
页码：4645-4649
DOI：10.1073/pnas.79.15.4645
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The recombinant plasmid p102 based on pBR322 carrying approximately equal to 50% of the replicator proximal early region of simian virus 40 (SV40) DNA, including the viral origin of replication, has been constructed. It lacks a major part of the large tumor (T) antigen 3'-coding region, the T-antigen termination codon, and the polyadenylylation site. The plasmid was transferred together with the herpes simplex virus thymidine kinase (TK) gene as a selectable marker to mouse LTK- cells. TK+ cell clones were isolated and their high molecular weight DNAs were shown by DNA blotting and hybridization experiments to contain the SV40 DNA fragment from the recombinant. In some of these clones, heterogeneous expression of the SV40 DNA fragment could be detected by immunofluorescence while, in control experiments in which a plasmid containing the complete SV40 early DNA region was used, this extensive heterogeneity of T-antigen expression was not observed. RNA . DNA hybridization experiments showed that the SV40-specific RNA of those clones is polyadenylylated. The molecular weight of the T-antigen-related protein coded by p102 corresponded well to the expected coding capacity of the SV40 DNA fragment. Small tumor antigen was not expressed.
