Nucleic Acids Research, 1980, Vol. 8, No. 23 5715-5723
© 1980
MOLECULAR BIOLOGY |
Identification and partial characterization of an endogenous form of mouse mammary tumor virus that is transcribed into the virion-associated RNA genome
Department of Pathology, School of Medicine, University of California Davis, CA 95616, USA
Received July 31, 1980. Restriction mapping demonstrated the presence of several distinct proviral forms of mouse mammary tumor virus in the genome of GR mice. One of these proviruses (GR-MTV-2) was highly amplified in GR 3A cells, a cell line derived from a GR mammary tumor. By the criterion of restriction mapping, the amplified GR-MTV-2 provirus found in GR 3A cells was identical to the provirus found in Ml.19 cells, a rat cell line infected with virions obtained from GR 3A culture fluid. This result clearly implies that the GR-MTV-2 provirus in GR 3A cells was transcribed into the virion-associated viral RNA genome. Cleavage of either GR 3A or Ml.19 cell DNAs with the restriction enzyme Bgl II gave rise to a 2.6x106 dalton GR-MTV-2 proviral fragment (ca. 45% of the viral genome). This fragment was isolated and mapped with thirteen restriction enzymes.