title: The relationship between genomic RNAs of polycythaemic forms of spleen focus-forming Friend virus and its helper virus.
abstract: We have studied the relationship between Friend spleen focus-forming virus (SFFV) and its helper lymphoid leukaemia virus (LLV) by comparing RNase T1 fingerprints of genomic RNAs. Our data indicate that about 70% of the SFFV sequence is a perfect copy of parts of the helper genome. We conclude that our SFFV and LLV isolates have co-evolved very closely and that SFFV-specific sequences are not identical in different Friend virus isolates.
mesh_terms: D001483:Base Sequence; D005622:Friend murine leukemia virus / Q000235:genetics* / Q000472:pathogenicity; D005814:Genes, Viral; D006378:Helper Viruses / Q000235:genetics*; D009052:Leukemia Virus, Murine / Q000235:genetics*; D009843:Oligoribonucleotides / Q000235:genetics; D011086:Polycythemia / Q000382:microbiology; D012367:RNA, Viral / Q000235:genetics*
chemical_list: D009843:Oligoribonucleotides; D012367:RNA, Viral