Transfer of Murine Leukaemia and Murine Sarcoma Virus Genetic Information by Transfection with Isolated Metaphase Chromosomes

Abstract

SUMMARYChromosome-mediated transfer of murine leukaemia (MuLV) and murine sarcoma (MuSV) virus genetic information to uninfected recipient cells was investigated. Metaphase chromosomes from AKR MuLV-infected SC-1 mouse cells were incubated with NIH/3T3 cells. After several passages (1 to 3 weeks), infectious virions exhibiting reverse transcriptase activity and the characteristic host range of ecotropic, N-tropic AKR virus appeared in the supernatant fluids of the treated cells. Restriction endonuclease analysis of genomic DNA from transfected cells indicated that AKR proviral DNA was associated with the high molecular weight DNA of the host. These results demonstrate that the AKR MuLV genome can be stably transferred to uninfected recipient cells via isolated metaphase chromosomes. Although AKR virions are not able to infect heterologous cells, chromosomemediated transfection resulted in the establishment of productive AKR MuLV infection in mink cells. Thus, the use of chromosomes to transfer virus genes can circumvent the natural host restriction barrier. In other experiments, it was shown that normal NIH/3T3 cells were transformed after exposure to metaphase chromosomes isolated from an MuSV-infected, non-producer line. Foci were detected 14 to 21 days after chromosome treatment and were shown to contain true viral transformants since transforming virus was produced after superinfection with MuLV.

Murine leukemia virus mutant with a frameshift in the reverse transcriptase coding region: implications for pol gene structure

“…Cells and viruses. Conditions for growth of the SC-1i NIH-3T3, mink (CCL64), 3T3FL (17), and clone 23 (16) cell lines have been described previously (16,31,32). AKR-L1 MuLV was obtained from Marilyn Lander and was propagated in SC-1 cells (32).…”

“…Cell clones were first selected for their ability to grow in the presence of the neomycin analog G418, E(oRI and Psul. High-molecular-weight cellular DNA was isolated from clone 23 virus-infected mink cells (CL 23) and from AKR MuLV-infected SC-1 cells (AKR) as described previously (31). DNA samples were digested with EcoRI (clone 23) and Pstl (AKR and clone 23), subjected to electrophoresis in a 0.6% agarose gel (25 V. 24 h).…”