Phylogenetic Analysis of the Entire Genome of Influenza A (H3N2) Viruses from Japan: Evidence for Genetic Reassortment of the Six Internal Genes

摘要: Nucleotide sequences of all eight RNA segments 10 human H3N2 influenza viruses isolated during a 5-year period from 1993 to 1997 were determined and analyzed phylogenetically in order define the evolutionary pathways genes parallel fashion. It was evident that hemagglutinin neuraminidase these evolved essentially single lineage amino acid changes accumulated sequentially with respect time. In contrast, differences internal proteins erratic did not accumulate over Parallel analysis phylogenetic patterns revealed six linked surface glycoproteins. Genes coding for basic polymerase-1, nucleoprotein, matrix isolates closest those earlier 1994. Furthermore, four 1995 epidemic season consistently divided into two distinct branch clusters, contained PB2 apparently originating before 1993. apparent lack correlation between topologies trees glycoproteins reflection genetic reassortment among viruses. This is first evidence demonstrating occurrence involving protein variability coincided marked increases activity 1997.