Isolation of two novel envelope recombinant leukemogenic viruses from Moloney leukemia virus stocks

Two dual recombinant murine leukemia viruses were isolated from Moloney leukemia virus passed in France for 17 years. These new isolates share most of the biological properties of previously described HIX virus isolated from a line of Moloney virus maintained in the United States. However, they differ from the HIX virus and from other recombinant viruses by the absence of a xenotropic oligopeptide thought to have been characteristic of all xenotropic and recombinant virus envelope glycoprotein.