Effect of Fv-1 gene product on proviral DNA formation and integration in cells infected with murine leukemia viruses
The amounts of unintegrated murine leukemia virus-specific DNA detected by molecular hybridization in extracts of Fv-1n/n (strains NIH/3T3, SIM) or Fv-1b/b (strains JLS-V9, SIM.R) mouse cells after infection with N- or B-tropic viruses were found to be the same in both permissive and resistant cells. Therefore, formation of DNA products from the viral RNA template does not appear to be grossly affected by the Fv-1 gene product. Integration of virus-specific DNA into chromosomal cellular DNA was assayed by hybridization of radioactive complementary DNA to DNA from infected cells. With either NIH/3T3 or SIM.R cells infected with N- or B-tropic viruses, integration of proviral DNA could be detected in permissive cells but not in nonpermissive cells. The Fv-1 gene product therefore appears to prevent integration of proviral DNA.
© 1976 by the National Academy of Sciences. Contributed by David Baltimore, April 12, 1976. We thank Drs. Robert Weinberg and Philip Sharp for helpful discussions, and Ms. Anne Cotellessa for her excellent technical assistance. This work was supported by Grant VC-4G from the American Cancer Society and U.S. Public Health Service Grant CA-14051 from the National Cancer Institute. P.J. is a recipient of a Centennial Fellowship of the Medical Research Council of Canada. D.B. is a Research Professor of the American Cancer Society.