title: Influenza B virus evolution: co-circulating lineages and comparison of evolutionary pattern with those of influenza A and C viruses.
abstract: Sequence analyses and comparison of the genes coding for the nonstructural (NS) and hemagglutinin (HA) proteins of different influenza B viruses isolated between 1940 and 1987 reveal that the number of substitutions is not always proportional to the time between isolates. Examination of 14 influenza B virus NS gene and 10 HA gene sequences by the maximum parsimony method suggested that--as with influenza C viruses--there are multiple evolutionary lineages which can coexist for considerable periods of time. Comparison of the sequence divergence among genes of viruses belonging to type A, B, and C virus suggests that, in man, influenza B viruses evolve slower than A viruses and faster than C viruses. We propose an evolutionary model for influenza B viruses that is intermediate between the pattern for human influenza A viruses and that for influenza C viruses.
authors.affiliation: Department of Microbiology, Mount Sinai School of Medicine, City University of New York, New York 10029.
authors.forename: M
authors.initials: M
authors.lastname: Yamashita
authors.forename: M
authors.initials: M
authors.lastname: Krystal
authors.forename: W M
authors.initials: WM
authors.lastname: Fitch
authors.forename: P
authors.initials: P
authors.lastname: Palese
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D005814:Genes, Viral; D006389:Hemagglutinins, Viral / Q000235:genetics*; D006801:Humans; D009980:Influenza A virus / Q000235:genetics; D009981:Influenza B virus / Q000235:genetics*; D009982:Gammainfluenzavirus / Q000235:genetics; D008969:Molecular Sequence Data; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D006389:Hemagglutinins, Viral; D014764:Viral Proteins