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:1980
卷号:77
期号:8
页码:4674-4678
DOI:10.1073/pnas.77.8.4674
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Circular DNA intermediates of Harvey murine sarcoma virus (Ha-MuSV) have been cloned in lambda gtWES . lambda B and shown to be capable of transforming mouse NIH 3T3 cells [Hager, G. L., Chang, E. H., Chan, H. W., Garon, C. F., Israel, M. A., Martin, M. A., Scolnick, E. M. & Lowy, D. R. (1979) J. Virol. 31, 795-809]. By using the cloned Ha-MuSV DNA insert as a parental genome, we have constructed a series of insertion-deletion mutants by inserting an octomer containing the Sal I linker sequence (G-G-T-C-G-A-C-C) into various regions of the Ha-MuSV genome after partial digestion with Hae III. After ligation into lambda gtWES . lambda B-Sal I vector molecules, the mutant Ha-MuSV DNAs were cloned. Fourteen insertion-deletion mutants have been mapped by restriction enzyme digestion, and their biological activities have been correlated with the locations of mutations. The mutants whose lesion mapped within 3.0 kilobases (kb) frm the 3'-end of the Ha-MuSV genome retained full transforming ability. The mutants containing the Sal I linker insertion at 0.4 or 1.5 kb from the 5'-end also retained transforming ability, but the number of foci induced by the DNAs in transfection assays was greatly reduced. However, a mutant containing a deletion of 1.5 kb at the 5'-end and a mutant with a deletion of the sequences between 1.0 and 1.5 kb from the 5'-end completely lost their transforming potential. A model for the transforming region of Ha-MuSV is discussed. Furthermore, because Ha-MuSV sequences can be rescued from the mouse cells transformed by these mutants using Moloney murine leukemia virus as a helper virus, it implies that the in vitro modified DNAs may be converted into genuine mutant viruses.