title: On the origin of the H1N1 (A/USSR/90/77) influenza virus.
abstract: The influenza virus H1N1 (the A/USSR/90/77 strain) that reappeared in 1977 after the H1N1 influenza viruses had disappeared from the human population, is compared with the A/FM/1/47 and the A/FW/1/50 influenza viruses by the method of oligonucleotide mapping of individual segments of the viral RNAs. Seven genes of the A/USSR/90/77 virus appear to be very similar to the corresponding genes of the A/FW/1/50 virus, whereas the gene coding for the M protein displays considerable homology to the corresponding gene of the A/FM/1/47 virus. The data demonstrate that the A/USSR/90/77 strain is a recombinant virus.
mesh_terms: D005814:Genes, Viral; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000235:genetics*; D009698:Nucleoproteins / Q000235:genetics; D009843:Oligoribonucleotides / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis; D011995:Recombination, Genetic; D014763:Viral Matrix Proteins; D014764:Viral Proteins / Q000235:genetics
chemical_list: D009698:Nucleoproteins; D009843:Oligoribonucleotides; D012367:RNA, Viral; D014763:Viral Matrix Proteins; D014764:Viral Proteins