title: Evolution of the hemagglutinin gene of influenza B virus was driven by both positive and negative selection pressures.
abstract: Nucleotide sequences of the hemagglutinin (HA) gene of twelve influenza B strains and their deduced amino acid sequences were extracted from the GenBank and compared to those of early isolates. Separate analyses of nonsynonymous and synonymous substitutions for the HA1 and HA2 regions individually indicate that the percentage of nonsynonymous substitutions in the HA1 ranges from 44.4-56.0% but in the HA2 from 0.0-6.5%. The results suggest that positive selection as well as negative selection played a role in the evolution of the influenza B HA gene with the former acting on the HA1 and the latter on the HA2.
authors.affiliation: Surveillance, Influenza and Viral Exanthemata, Laboratory Centre for Disease Control, Ottawa, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Zou
authors.forename: I
authors.initials: I
authors.lastname: Prud'homme
authors.forename: J M
authors.initials: JM
authors.lastname: Weber
mesh_terms: D000595:Amino Acid Sequence; D000940:Antigenic Variation / Q000235:genetics; D001483:Base Sequence; D016208:Databases, Factual; D019143:Evolution, Molecular; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D009981:Influenza B virus / Q000235:genetics*; D008969:Molecular Sequence Data; D012641:Selection, Genetic; D016415:Sequence Alignment
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus