title: Molecular changes associated with adaptation of equine influenza H3N8 virus in embryonated chicken eggs.
abstract: Embryonated chicken eggs (ECEs) are routinely used to isolate equine influenza virus. Propagation of the virus in ECEs results in selection of variants. In the present study, we determined nucleotide sequences of entire coding regions of parent A/equine/Tottori/1/07 (H3N8) and its derivatives that have different passage histories in ECE. After 12 passages, nucleotide sequence analysis predicted 3 amino acid substitutions in hemagglutinin (HA; 2 in HA1 and 1 in HA2). The two amino acid substitutions in HA1 were located in the vicinity of the cell receptor-binding site. Three other amino acid substitutions were predicted in internal proteins, 1 in the M1, 1 in the NP and 1 in the PA. This is the first report showing mutations in the internal protein genes of equine influenza virus associated with adaptation to ECE.
authors.affiliation: Laboratory of Veterinary Hygiene, Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan.
authors.forename: Awlad Wadair Ali
authors.initials: AW
authors.lastname: Said
authors.forename: Michiko
authors.initials: M
authors.lastname: Kodani
authors.forename: Tatsufumi
authors.initials: T
authors.lastname: Usui
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ito
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo / Q000821:virology*; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D053123:Influenza A Virus, H3N8 Subtype / Q000502:physiology*; D009154:Mutation; D012367:RNA, Viral / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014776:Virus Cultivation / Q000662:veterinary*
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins