Analyses of variability of eight gene fragments of influenza A (H1N1) virus A/New York/1669/2009 (H1N1) and its pandemicity.

In order to explore the internus reasons of the recent pandemic influenza and the variability of eight gene fragments of influenza A(H1N1) virus,a typical influenza A(H1N1) virus A/NewYork/1669/2009(H1N1) broke out recently was analyzed and compared on its eight gene fragments of PA,NP,M,PB1,PB2,NA,HA,and NS by BLAST and CLUSTAL X bioinformatics softwares.The results showed that PB1 and NP genes derived from human influenza virus,and HA,NA,NS,and M genes derived from swine influenza virus,while PB2 and PA genes derived from avian influenza virus.A new glycosylation site-NTT-was found in position site 249 of HA gene,and another new glycosylation site-NFSI-was found in position site 386 of NA gene,too.Meanwhile,the changes of 3 amino acids on HA gene led to the changes of 6 potential antigenic determinants,and 5 of 12 potential antigenic determinants of NA gene changed.The recombination and high-frequency variability of these antigenic determinants might be the primary cause of the pandemic influenza outbreak.