title: The endogenous proviral mouse mammary tumor virus genes of the GR mouse are not identical and only one corresponds to the exogenous virus.
abstract: The endogenous proviral copies of mouse mammary tumor virus (MMTV) were selected from a gene library of GR mouse DNA. We obtained five different lambda. MMTV recombinant clones. Four of them correspond to the 3' Eco RI fragments of the endogenous proviruses an one comprises an intact MMTV provirus with 2 to 3 kb of flanking mouse genomic DNA. Heteroduplex formation followed by S1 digestion under stringent conditions shows that there is nucleotide sequence heterology among the cloned endogenous proviral copies. Only one endogenous proviral copy, associated with the mtv-2 locus, was found to be totally homologous to the exogenous proviral DNA.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis*; D015246:Deoxyribonuclease EcoRI; D004587:Electrophoresis, Agar Gel; D004720:Endonucleases / Q000378:metabolism; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D051379:Mice; D015719:Single-Strand Specific DNA and RNA Endonucleases
chemical_list: D004279:DNA, Viral; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; D015719:Single-Strand Specific DNA and RNA Endonucleases