title: Genome organisation of the FBR-osteosarcoma virus complex: identification of a subgenomic fos-specific message.
abstract: The FBR murine virus complex together with the FBJ murine virus complex are known to be bone tumor inducers in newborn mice. Both transforming viruses have transduced c-proto-fos-derived sequences in their genome. FBR-MuSV was molecularly cloned as a biologically active 10-kbp EcoRI fragment from non-productively transformed rat embryo fibroblasts into Charon phage 4A (lambda MOL503) and subsequently subcloned in plasmid pBR322 (pMOL503). Its natural associated helper FBR-MuLV, excized as an internal 8.2-kbp PstI proviral DNA fragment from chronically infected NIH/3T3 cells, was cloned into the unique PstI site of pBR322. Comparative analysis of the restriction maps of FBR-MuSV and FBR-MuLV together with the electron microscopic analysis of heteroduplex DNA molecules formed between both molecular clones suggested that FBR-MuLV is the parental virus of FBR-MuSV. fos- and fox-specific DNA hybridisation probes identified a genomic sized 3.3-kb mRNA and a subgenomic 2.2-kb messenger RNA. Using a 5'-gag hybridisation probe, only the genomic 3.3-kb RNA molecule was detected, demonstrating that a donor splice site is present upstream of the gag sequences and used to generate the fos-specific 2.2-kb subgenomic mRNA.
mesh_terms: D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005814:Genes, Viral; D009052:Leukemia Virus, Murine / Q000235:genetics; D051379:Mice; D008854:Microscopy, Electron; D009693:Nucleic Acid Hybridization; D009857:Oncogenes; D012516:Osteosarcoma; D010957:Plasmids; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics*; D051381:Rats; D009053:Sarcoma Viruses, Murine / Q000235:genetics*; D014779:Virus Replication
chemical_list: D004274:DNA, Recombinant; D004279:DNA, Viral; D012333:RNA, Messenger; D012367:RNA, Viral; D004262:DNA Restriction Enzymes