Memorandum from Robert J. Huebner, National Institutes of Health to Harold Varmus [regarding Varmus' manuscript on the
detection of new and additional virus-specific DNA sequences in chick embryo fibroblasts after infection by RSV]
Number of Image Pages:
1 (42,247 Bytes)
1974-05-20 (May 20, 1974)
Huebner, Robert J.
National Institutes of Health (U.S.)
Original Repository: University of California, San Francisco. Archives and Special Collections. Harold E. Varmus Papers
This item is in the public domain. It may be used without permission.
Medical Subject Headings (MeSH):
Avian Sarcoma Viruses
Retroviruses and the Genetic Origins of Cancer, 1970-1993
SUBJECT: MS. -- Detection of new and additional virus-specific DNA sequences in chick embryo fibroblasts after infection by
This is a very interesting, useful and significant contribution. I think what most needs to be determined is, what is RSV?
It's been around 50+ years, is certainly a recombinant, and like AMV according to Rubin, a mixture of several ALV phenotypes
(RIF-1, 2, etc.). I would suggest making DNA probes from natural ALV's isolated from RIF-free colonies. Both ecotropic
and xenotropic viruses are certainly present and/or activatable. RSV and MSV have not turned up in large numbers of sarcomas
in chickens and mice in my 10 years of extensive surveys for natural sarcoma viruses. There has never been one epidemic of
sarcoma in any species. Existing RSV and MSV lab strains are laboratory-created artifacts and could not represent faithfully
natural virus or viral genomes in natural host cells. There are almost as many variants of RSV and MSV as there are investigators
working with them.