Sequence and phylogenetic analysis of nucleoprotein gene in Iranian H۹N۲ avian influenza viruses

Objective: Survey of molecular characterization of nucleoprotein gene of H۹N۲ avian influenza viruses and determination of the genetic relationship of Iranian H۹N۲ viruses and other Asian viruses. Materials and Methods: The nucleoprotein (NP) genes from ۴ isolates of H۹N۲ viruses isolated from commercial chickens in Iran during ۲۰۰۸-۲۰۰۹ were amplified by RT-PCR method and sequenced. Nucleotide sequences (orf) of the NP genes were used for phylogenetic tree construction. Results: Nucleotide sequence analysis of the NP gene showed that the Iranian virus isolates did not exhibit insertions or deletions within nucleoprotein (NP) gene as compare with their prototype A/turkey/winconsin/۶۶; however numerous point mutations were occurred in the gene length of these viruses similar to the previous Iranian strains. Nucleotide sequence analysis showed that these isolates are very closely related (۹۶/۷-۹۹/۶) and shared a homology of ۹۱/۹-۹۲/۳% and ۹۱/۵-۹۲% with ۲ human isolates A/HK/۱۰۷۳/۹۹ and A/Hk/۲۱۰۸/۲۰۰۳, respectively. Phylogenetic analysis of the NP gene showed that all the NP genes of the Iranian H۹N۲ viruses fall into a single group within a G۱-like sublineage which had contributed as donor of six internal genes to H۵N۱ a highly pathogenic avian influenza. Conclusions: The current study indicated that the NP gene of H۹N۲ influenza viruses circulating in Iran during the past years were well conserved. It seems that the differences between these Iranian virus isolates are the result of accumulation of point mutations among them.

کلیدواژه ها:

Iran ، Phylogenetic Analysis ، Nucleoprotein Gene ، Avian Influenza Viruses ، ایران ، آنالیز فیلوژنیتک ، ژن نوکلئوپروتئین ، آنفولانزای پرندگان H۹N۲