title: Molecular mechanisms of reversion to the ts+ (non-temperature-sensitive) phenotype of influenza A cold-adapted (ca) virus strains.
abstract: A ts+ ca- (non-temperature-sensitive, non-cold-adapted) revertant of the A/Leningrad/134/47/57 ca strain influenza virus [A/Leningrad/134/47/ts+18/1957(H2N2)], obtained in our previous study, lost phenotypic manifestation of ts mutations by the PB2, NP and NS genes, although, according to sequencing data, it acquired only two true reversions of a mutation in the PB2 and PB1 genes. Direct sequencing showed the appearance of 27 additional mutations (13 coding) in the genes encoding the PB2, PB1, PA, NP, M and NS proteins of the revertant, along with the above-mentioned two true reversions. We conjecture that some of these mutations suppressed phenotypic manifestation of ts mutations in the NS and NP genes.
authors.affiliation: Mechnikov Research Institute for Vaccines and Sera, 115088, 1st Dubrovskaja Str. 15, Moscow, Russia.
authors.forename: T M
authors.initials: TM
authors.lastname: Tsfasman
authors.affiliation: Mechnikov Research Institute for Vaccines and Sera, 115088, 1st Dubrovskaja Str. 15, Moscow, Russia.
authors.forename: S G
authors.initials: SG
authors.lastname: Markushin
authors.affiliation: Mechnikov Research Institute for Vaccines and Sera, 115088, 1st Dubrovskaja Str. 15, Moscow, Russia.
authors.forename: I I
authors.initials: II
authors.lastname: Akopova
authors.affiliation: Mechnikov Research Institute for Vaccines and Sera, 115088, 1st Dubrovskaja Str. 15, Moscow, Russia.
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Ghendon
mesh_terms: D000064:Acclimatization; D003080:Cold Temperature; D005816:Genetic Complementation Test; D005838:Genotype; D006801:Humans; D053121:Influenza A Virus, H2N2 Subtype / Q000235:genetics / Q000502:physiology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control; D009154:Mutation; D010641:Phenotype; D018807:Polymorphism, Single-Stranded Conformational; D011995:Recombination, Genetic; D017361:Viral Nonstructural Proteins / Q000235:genetics
chemical_list: D017361:Viral Nonstructural Proteins