Characterization of a highly oncogenic murine leukemia virus from wild mice.

We have isolated a highly lymphomagenic wild mouse virus by passage of a weakly oncogenic amphotropic murine leukaemia virus (MuLV-A) in NIH Swiss mice. This virus is similar in host range, interference and neutralization properties to that of the inoculated amphotropic virus but is distinct from it biochemically and causes lymphomas in 90-100% of mice within 1-2 months. Our results indicate that this highly oncogenic virus is a recombinant of wild mouse MuLV-A and sequences related to env gene region of the endogenous xenotropic virus of NIH Swiss mice.