title: Sequence changes in the live attenuated, cold-adapted variants of influenza A/Leningrad/134/57 (H2N2) virus.
abstract: Nucleotide sequences were determined for the RNA segments coding for proteins other than the hemagglutinin and neuraminidase of the A/Leningrad/134/57 (H2N2) wild-type (A/Len/wt) virus and its two cold-adapted (ca) and attenuated variants, A/Leningrad/134/17/57 (A/Len/17/ca) and A/Leningrad/134/47/57 (A/Len/47/ca) that are used in the U.S.S.R. in the preparation of reassortant live attenuated vaccines. Ten nucleotide differences were detected between the sequences of the A/Len/wt and A/Len/17/ca viruses; of these, eight were deduced to encode amino acid (aa) substitutions. One aa substitution each was predicted for the PB2, M1, M2, and NS2 proteins, whereas two aa substitutions each were predicted for the PB1, and PA proteins of the A/Len/17/ca virus. Four additional nucleotide changes were found in the genome of the A/Len/47/ca virus; three of these were detected to code for one additional aa substitution each for the PB2, PB1, and NP proteins.
authors.affiliation: Research Institute for Viral Preparations, Academy of Medical Sciences of the USSR, Moscow.
authors.forename: A I
authors.initials: AI
authors.lastname: Klimov
authors.forename: N J
authors.initials: NJ
authors.lastname: Cox
authors.forename: W V
authors.initials: WV
authors.lastname: Yotov
authors.forename: E
authors.initials: E
authors.lastname: Rocha
authors.forename: G I
authors.initials: GI
authors.lastname: Alexandrova
authors.forename: A P
authors.initials: AP
authors.lastname: Kendal
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003080:Cold Temperature; D004279:DNA, Viral; D053121:Influenza A Virus, H2N2 Subtype; D009980:Influenza A virus / Q000235:genetics*; D007252:Influenza Vaccines / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D012367:RNA, Viral / Q000235:genetics; D014613:Vaccines, Attenuated / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D007252:Influenza Vaccines; D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014764:Viral Proteins