Objective:To determine the molecular characterization of Polymerase complex(PA,PB1 and PB2) genes of H9N2 avian influenza viruses and the genetic relalionsliip of Iranian H9N2 viruses and other Asian viruses.Methods:T...Objective:To determine the molecular characterization of Polymerase complex(PA,PB1 and PB2) genes of H9N2 avian influenza viruses and the genetic relalionsliip of Iranian H9N2 viruses and other Asian viruses.Methods:The Polymerase complex(PA,PBl and PB2) genes from seven isolates of H9N2 viruses isolated from commercial chickens in Iran during 2008-2009 were amplified(by RT-PCR method) and sequenced.Nucleotide sequences(Open Reading Frame: orf) of the PA,PBl and PB2 genes were used for phylogenetic tree construction.Results:Most PB2 and PA genes of the H9N2 viruses isolated in 2008-2009 belonged to the unknown avian sublineage which grouped with the 2004 Pakistani H7N3 viruses.The PBl genes of Iranian viruses indicated greater genetic diversity and shared a high level of similarity to PBl genes from either HS or H7 subtypes with compared to established H9N2 Eurasian sublineages.Condusions:Our findings demonstrated that the H9N2 viruses in Iran exhibit striking reassortment which has led to the generation of new genotypes.展开更多
基金Supported by The Islamic Azad University,Shoushtar Branch(grantNo.8254)
文摘Objective:To determine the molecular characterization of Polymerase complex(PA,PB1 and PB2) genes of H9N2 avian influenza viruses and the genetic relalionsliip of Iranian H9N2 viruses and other Asian viruses.Methods:The Polymerase complex(PA,PBl and PB2) genes from seven isolates of H9N2 viruses isolated from commercial chickens in Iran during 2008-2009 were amplified(by RT-PCR method) and sequenced.Nucleotide sequences(Open Reading Frame: orf) of the PA,PBl and PB2 genes were used for phylogenetic tree construction.Results:Most PB2 and PA genes of the H9N2 viruses isolated in 2008-2009 belonged to the unknown avian sublineage which grouped with the 2004 Pakistani H7N3 viruses.The PBl genes of Iranian viruses indicated greater genetic diversity and shared a high level of similarity to PBl genes from either HS or H7 subtypes with compared to established H9N2 Eurasian sublineages.Condusions:Our findings demonstrated that the H9N2 viruses in Iran exhibit striking reassortment which has led to the generation of new genotypes.
