Correlation analysis of type A influenza virus genetic variation characteristic with survival selective pressure / 中华传染病杂志

ABSTRACT

Objective Study the relationship between type A influenza virus genetic variation with survival selective pressure, help for the finding of possible vaccine conserved antigen target. Methods Select seven strains of same HA (Hemagglutinin) serotype, regional and isolation time closely related type A influenza virus with full HA gene coding sequence; use Blast2 program to calculate the parameter of nucleotide conservative, amino acid conservative, mutation ratio of codon 3rd (over) non 3rd locus, survival selective pressure indicator of these virus strains; analysis the parameters relationship with survival selective pressure indicator. Results Nucleotide conservative of HA gene is significantly lower than that of other genes; amino acid conservative of HA gene is similar with NS gene, all lower than that of other genes; genetic variation of HA gene is under survival selective pressure; selective pressure toward NS, PB1 gene is relatively lower than that toward NA, NP gene; survival selective pressure indicator is strongly correlated with mutation frequency upon codon 3rd locus. Conclusions Genetic variation of influenza virus is determined both by mechanism of relax replication model and survival selective pressure; genetic conservative of each gene is different, NA, NP gene could be selected as possible vaccine target for their relative high conservative, HA gene possesses medium genetic conservative with prospective of finding more conserved epitope region within its full sequence, NS, PB1 are not recommended as vaccine candidate for their relative low genetic conservative.