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Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian Influenza Viruses with Allele A and B Nonstructural Gene in Northern Pintail (Anas acuta) Ducks Wintering in Japan

Identifieur interne : 000987 ( Pmc/Corpus ); précédent : 000986; suivant : 000988

Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian Influenza Viruses with Allele A and B Nonstructural Gene in Northern Pintail (Anas acuta) Ducks Wintering in Japan

Auteurs : Alam Jahangir ; Sakchai Ruenphet ; Nadia Sultana ; Dany Shoham ; Kazuaki Takehara

Source :

RBID : PMC:3540751

Abstract

The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in pintail wintering in Japan.


Url:
DOI: 10.1155/2012/847505
PubMed: 23320157
PubMed Central: 3540751

Links to Exploration step

PMC:3540751

Le document en format XML

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<italic>Anas acuta</italic>
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<div1 type="bibliography">
<listBibl>
<biblStruct>
<analytic>
<author>
<name sortKey="Campitelli, L" uniqKey="Campitelli L">L Campitelli</name>
</author>
<author>
<name sortKey="Fabiani, C" uniqKey="Fabiani C">C Fabiani</name>
</author>
<author>
<name sortKey="Puzelli, S" uniqKey="Puzelli S">S Puzelli</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y Kawaoka</name>
</author>
<author>
<name sortKey="Krauss, S" uniqKey="Krauss S">S Krauss</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Claas, Ecj" uniqKey="Claas E">ECJ Claas</name>
</author>
<author>
<name sortKey="Osterhaus, Adme" uniqKey="Osterhaus A">ADME Osterhaus</name>
</author>
<author>
<name sortKey="Van Beek, R" uniqKey="Van Beek R">R Van Beek</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Lin, Yp" uniqKey="Lin Y">YP Lin</name>
</author>
<author>
<name sortKey="Shaw, M" uniqKey="Shaw M">M Shaw</name>
</author>
<author>
<name sortKey="Gregory, V" uniqKey="Gregory V">V Gregory</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Guan, Y" uniqKey="Guan Y">Y Guan</name>
</author>
<author>
<name sortKey="Shortridge, Kf" uniqKey="Shortridge K">KF Shortridge</name>
</author>
<author>
<name sortKey="Krauss, S" uniqKey="Krauss S">S Krauss</name>
</author>
<author>
<name sortKey="Li, Ph" uniqKey="Li P">PH Li</name>
</author>
<author>
<name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y Kawaoka</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Karasin, Ai" uniqKey="Karasin A">AI Karasin</name>
</author>
<author>
<name sortKey="West, K" uniqKey="West K">K West</name>
</author>
<author>
<name sortKey="Carman, S" uniqKey="Carman S">S Carman</name>
</author>
<author>
<name sortKey="Olsen, Cw" uniqKey="Olsen C">CW Olsen</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Peiris, Jsm" uniqKey="Peiris J">JSM Peiris</name>
</author>
<author>
<name sortKey="Guan, Y" uniqKey="Guan Y">Y Guan</name>
</author>
<author>
<name sortKey="Markwell, D" uniqKey="Markwell D">D Markwell</name>
</author>
<author>
<name sortKey="Ghose, P" uniqKey="Ghose P">P Ghose</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
<author>
<name sortKey="Shortridge, Kf" uniqKey="Shortridge K">KF Shortridge</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Ma, W" uniqKey="Ma W">W Ma</name>
</author>
<author>
<name sortKey="Vincent, Al" uniqKey="Vincent A">AL Vincent</name>
</author>
<author>
<name sortKey="Gramer, Mr" uniqKey="Gramer M">MR Gramer</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Shoham, D" uniqKey="Shoham D">D Shoham</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Tong, S" uniqKey="Tong S">S Tong</name>
</author>
<author>
<name sortKey="Li, Y" uniqKey="Li Y">Y Li</name>
</author>
<author>
<name sortKey="Rivailler, P" uniqKey="Rivailler P">P Rivailler</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y Kawaoka</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Hatta, H" uniqKey="Hatta H">H Hatta</name>
</author>
<author>
<name sortKey="Gao, P" uniqKey="Gao P">P Gao</name>
</author>
<author>
<name sortKey="Halfmann, P" uniqKey="Halfmann P">P Halfmann</name>
</author>
<author>
<name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y Kawaoka</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Li, Z" uniqKey="Li Z">Z Li</name>
</author>
<author>
<name sortKey="Chen, H" uniqKey="Chen H">H Chen</name>
</author>
<author>
<name sortKey="Jiao, P" uniqKey="Jiao P">P Jiao</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Li, Z" uniqKey="Li Z">Z Li</name>
</author>
<author>
<name sortKey="Jiang, Y" uniqKey="Jiang Y">Y Jiang</name>
</author>
<author>
<name sortKey="Jiao, P" uniqKey="Jiao P">P Jiao</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Noah, Dl" uniqKey="Noah D">DL Noah</name>
</author>
<author>
<name sortKey="Twu, Ky" uniqKey="Twu K">KY Twu</name>
</author>
<author>
<name sortKey="Krug, Rm" uniqKey="Krug R">RM Krug</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Seo, Sh" uniqKey="Seo S">SH Seo</name>
</author>
<author>
<name sortKey="Hoffmann, E" uniqKey="Hoffmann E">E Hoffmann</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Jahangir, A" uniqKey="Jahangir A">A Jahangir</name>
</author>
<author>
<name sortKey="Watanabe, Y" uniqKey="Watanabe Y">Y Watanabe</name>
</author>
<author>
<name sortKey="Chinen, O" uniqKey="Chinen O">O Chinen</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Jahangir, A" uniqKey="Jahangir A">A Jahangir</name>
</author>
<author>
<name sortKey="Ruenphet, S" uniqKey="Ruenphet S">S Ruenphet</name>
</author>
<author>
<name sortKey="Ueda, S" uniqKey="Ueda S">S Ueda</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Jahangir, A" uniqKey="Jahangir A">A Jahangir</name>
</author>
<author>
<name sortKey="Ruenphet, S" uniqKey="Ruenphet S">S Ruenphet</name>
</author>
<author>
<name sortKey="Shoham, D" uniqKey="Shoham D">D Shoham</name>
</author>
<author>
<name sortKey="Okamura, M" uniqKey="Okamura M">M Okamura</name>
</author>
<author>
<name sortKey="Nakamaura, M" uniqKey="Nakamaura M">M Nakamaura</name>
</author>
<author>
<name sortKey="Takehara, K" uniqKey="Takehara K">K Takehara</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Hoffmann, E" uniqKey="Hoffmann E">E Hoffmann</name>
</author>
<author>
<name sortKey="Stech, J" uniqKey="Stech J">J Stech</name>
</author>
<author>
<name sortKey="Guan, Y" uniqKey="Guan Y">Y Guan</name>
</author>
<author>
<name sortKey="Webster, Rg" uniqKey="Webster R">RG Webster</name>
</author>
<author>
<name sortKey="Perez, Dr" uniqKey="Perez D">DR Perez</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Tamura, K" uniqKey="Tamura K">K Tamura</name>
</author>
<author>
<name sortKey="Dudley, J" uniqKey="Dudley J">J Dudley</name>
</author>
<author>
<name sortKey="Nei, M" uniqKey="Nei M">M Nei</name>
</author>
<author>
<name sortKey="Kumar, S" uniqKey="Kumar S">S Kumar</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Liu, S" uniqKey="Liu S">S Liu</name>
</author>
<author>
<name sortKey="Ji, K" uniqKey="Ji K">K Ji</name>
</author>
<author>
<name sortKey="Chen, J" uniqKey="Chen J">J Chen</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Ludwig, S" uniqKey="Ludwig S">S Ludwig</name>
</author>
<author>
<name sortKey="Schultz, U" uniqKey="Schultz U">U Schultz</name>
</author>
<author>
<name sortKey="Mandler, J" uniqKey="Mandler J">J Mandler</name>
</author>
<author>
<name sortKey="Fitch, Wm" uniqKey="Fitch W">WM Fitch</name>
</author>
<author>
<name sortKey="Scholtissek, C" uniqKey="Scholtissek C">C Scholtissek</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Zohari, S" uniqKey="Zohari S">S Zohari</name>
</author>
<author>
<name sortKey="Gyarmati, P" uniqKey="Gyarmati P">P Gyarmati</name>
</author>
<author>
<name sortKey="Thoren, P" uniqKey="Thoren P">P Thorén</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Li, Y" uniqKey="Li Y">Y Li</name>
</author>
<author>
<name sortKey="Lin, Z" uniqKey="Lin Z">Z Lin</name>
</author>
<author>
<name sortKey="Shi, J" uniqKey="Shi J">J Shi</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Jahangir, A" uniqKey="Jahangir A">A Jahangir</name>
</author>
<author>
<name sortKey="Ruenphet, S" uniqKey="Ruenphet S">S Ruenphet</name>
</author>
<author>
<name sortKey="Shoham, D" uniqKey="Shoham D">D Shoham</name>
</author>
<author>
<name sortKey="Okamura, M" uniqKey="Okamura M">M Okamura</name>
</author>
<author>
<name sortKey="Nakamaura, M" uniqKey="Nakamaura M">M Nakamaura</name>
</author>
<author>
<name sortKey="Takehara, K" uniqKey="Takehara K">K Takehara</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Kawaoka, Y" uniqKey="Kawaoka Y">Y Kawaoka</name>
</author>
<author>
<name sortKey="Gorman, Ot" uniqKey="Gorman O">OT Gorman</name>
</author>
<author>
<name sortKey="Ito, T" uniqKey="Ito T">T Ito</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Chen, R" uniqKey="Chen R">R Chen</name>
</author>
<author>
<name sortKey="Holmes, Ec" uniqKey="Holmes E">EC Holmes</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Duan, L" uniqKey="Duan L">L Duan</name>
</author>
<author>
<name sortKey="Campitelli, L" uniqKey="Campitelli L">L Campitelli</name>
</author>
<author>
<name sortKey="Fan, Xh" uniqKey="Fan X">XH Fan</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Shoham, D" uniqKey="Shoham D">D Shoham</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Zohari, S" uniqKey="Zohari S">S Zohari</name>
</author>
<author>
<name sortKey="Gyarmati, P" uniqKey="Gyarmati P">P Gyarmati</name>
</author>
<author>
<name sortKey="Ejdersund, A" uniqKey="Ejdersund A">A Ejdersund</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Spackman, E" uniqKey="Spackman E">E Spackman</name>
</author>
<author>
<name sortKey="Stallknecht, De" uniqKey="Stallknecht D">DE Stallknecht</name>
</author>
<author>
<name sortKey="Slemons, Rd" uniqKey="Slemons R">RD Slemons</name>
</author>
</analytic>
</biblStruct>
<biblStruct></biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Bianki, Vv" uniqKey="Bianki V">VV Bianki</name>
</author>
<author>
<name sortKey="Dobrynina, In" uniqKey="Dobrynina I">IN Dobrynina</name>
</author>
</analytic>
</biblStruct>
<biblStruct></biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Nicolai, Ca" uniqKey="Nicolai C">CA Nicolai</name>
</author>
<author>
<name sortKey="Flint, Pl" uniqKey="Flint P">PL Flint</name>
</author>
<author>
<name sortKey="Wege, Ml" uniqKey="Wege M">ML Wege</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Miller, Mr" uniqKey="Miller M">MR Miller</name>
</author>
<author>
<name sortKey="Takekawa, Jy" uniqKey="Takekawa J">JY Takekawa</name>
</author>
<author>
<name sortKey="Fleskes, Jp" uniqKey="Fleskes J">JP Fleskes</name>
</author>
<author>
<name sortKey="Orthmeyer, Dl" uniqKey="Orthmeyer D">DL Orthmeyer</name>
</author>
<author>
<name sortKey="Casazza, Ml" uniqKey="Casazza M">ML Casazza</name>
</author>
<author>
<name sortKey="Perry, Wm" uniqKey="Perry W">WM Perry</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Wahlgren, J" uniqKey="Wahlgren J">J Wahlgren</name>
</author>
<author>
<name sortKey="Waldenstrom, J" uniqKey="Waldenstrom J">J Waldenström</name>
</author>
<author>
<name sortKey="Sahlin, S" uniqKey="Sahlin S">S Sahlin</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Campitelli, L" uniqKey="Campitelli L">L Campitelli</name>
</author>
<author>
<name sortKey="Di Martino, A" uniqKey="Di Martino A">A Di Martino</name>
</author>
<author>
<name sortKey="Spagnolo, D" uniqKey="Spagnolo D">D Spagnolo</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="De Jong, Md" uniqKey="De Jong M">MD De Jong</name>
</author>
<author>
<name sortKey="Thanh, Tt" uniqKey="Thanh T">TT Thanh</name>
</author>
<author>
<name sortKey="Khanh, Th" uniqKey="Khanh T">TH Khanh</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Colman, Pm" uniqKey="Colman P">PM Colman</name>
</author>
<author>
<name sortKey="Hoyne, Pa" uniqKey="Hoyne P">PA Hoyne</name>
</author>
<author>
<name sortKey="Lawrence, Mc" uniqKey="Lawrence M">MC Lawrence</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Ward, P" uniqKey="Ward P">P Ward</name>
</author>
<author>
<name sortKey="Small, I" uniqKey="Small I">I Small</name>
</author>
<author>
<name sortKey="Smith, J" uniqKey="Smith J">J Smith</name>
</author>
<author>
<name sortKey="Suter, P" uniqKey="Suter P">P Suter</name>
</author>
<author>
<name sortKey="Dutkowski, R" uniqKey="Dutkowski R">R Dutkowski</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Zhu, Q" uniqKey="Zhu Q">Q Zhu</name>
</author>
<author>
<name sortKey="Yang, H" uniqKey="Yang H">H Yang</name>
</author>
<author>
<name sortKey="Chen, W" uniqKey="Chen W">W Chen</name>
</author>
</analytic>
</biblStruct>
<biblStruct>
<analytic>
<author>
<name sortKey="Obenauar, Jc" uniqKey="Obenauar J">JC Obenauar</name>
</author>
<author>
<name sortKey="Denson, J" uniqKey="Denson J">J Denson</name>
</author>
<author>
<name sortKey="Mehta, Pk" uniqKey="Mehta P">PK Mehta</name>
</author>
</analytic>
</biblStruct>
</listBibl>
</div1>
</back>
</TEI>
<pmc article-type="research-article">
<pmc-dir>properties open_access</pmc-dir>
<front>
<journal-meta>
<journal-id journal-id-type="nlm-ta">Influenza Res Treat</journal-id>
<journal-id journal-id-type="iso-abbrev">Influenza Res Treat</journal-id>
<journal-id journal-id-type="publisher-id">IRT</journal-id>
<journal-title-group>
<journal-title>Influenza Research and Treatment</journal-title>
</journal-title-group>
<issn pub-type="ppub">2090-1380</issn>
<issn pub-type="epub">2090-1399</issn>
<publisher>
<publisher-name>Hindawi Publishing Corporation</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="pmid">23320157</article-id>
<article-id pub-id-type="pmc">3540751</article-id>
<article-id pub-id-type="doi">10.1155/2012/847505</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Research Article</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian Influenza Viruses with Allele A and B Nonstructural Gene in Northern Pintail (
<italic>Anas acuta</italic>
) Ducks Wintering in Japan</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Jahangir</surname>
<given-names>Alam</given-names>
</name>
<xref ref-type="aff" rid="I1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="I2">
<sup>2</sup>
</xref>
<xref ref-type="corresp" rid="cor1">*</xref>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Ruenphet</surname>
<given-names>Sakchai</given-names>
</name>
<xref ref-type="aff" rid="I1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="I3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Sultana</surname>
<given-names>Nadia</given-names>
</name>
<xref ref-type="aff" rid="I1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Shoham</surname>
<given-names>Dany</given-names>
</name>
<xref ref-type="aff" rid="I1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="I4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Takehara</surname>
<given-names>Kazuaki</given-names>
</name>
<xref ref-type="aff" rid="I1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="I3">
<sup>3</sup>
</xref>
</contrib>
</contrib-group>
<aff id="I1">
<sup>1</sup>
Laboratory of Zoonoses, School of Veterinary Medicine, Kitasato University, Towada 034-8628, Japan</aff>
<aff id="I2">
<sup>2</sup>
Animal Health Research Division, Bangladesh Livestock Research Institute, Savar, Dhaka 1341, Bangladesh</aff>
<aff id="I3">
<sup>3</sup>
Tokyo University of Agriculture and Technology, Tokyo 183-0057, Japan</aff>
<aff id="I4">
<sup>4</sup>
Begin-Sadat Center for Strategic Studies, Bar-Ilan University 52900, Ramat Gan, Israel</aff>
<author-notes>
<corresp id="cor1">*Alam Jahangir:
<email>alamjahan2003@yahoo.com</email>
</corresp>
<fn fn-type="other">
<p>Academic Editor: Zichria Zakay-Rones</p>
</fn>
</author-notes>
<pub-date pub-type="ppub">
<year>2012</year>
</pub-date>
<pub-date pub-type="epub">
<day>25</day>
<month>12</month>
<year>2012</year>
</pub-date>
<volume>2012</volume>
<elocation-id>847505</elocation-id>
<history>
<date date-type="received">
<day>21</day>
<month>9</month>
<year>2012</year>
</date>
<date date-type="rev-recd">
<day>2</day>
<month>12</month>
<year>2012</year>
</date>
<date date-type="accepted">
<day>6</day>
<month>12</month>
<year>2012</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright © 2012 Alam Jahangir et al.</copyright-statement>
<copyright-year>2012</copyright-year>
<license xlink:href="https://creativecommons.org/licenses/by/3.0/">
<license-p>This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</license-p>
</license>
</permissions>
<abstract>
<p>The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern pintail (
<italic>Anas acuta</italic>
) ducks wintering in Japan. This study describes characteristics of pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in pintail wintering in Japan.</p>
</abstract>
</article-meta>
</front>
<body>
<sec id="sec1">
<title>1. Introduction</title>
<p>Influenza A virus infections in birds account for important inputs into the evolutionary porcine-human complex of this prominent anthropozoonotic pathogen. Among influenza A viruses, which broadly exhibit 17 HA and 9 NA antigenic subtypes, only three haemagglutinin (HA) subtypes (H1, H2, and H3) and two neuraminidase (NA) subtypes (N1 and N2) have circulated widely in swine and human populations since the 20th century [
<xref rid="B1" ref-type="bibr">1</xref>
]. Viruses from waterfowl reassorted with existing human and/or porcine influenza viruses to generate the 1957, 1968 [
<xref rid="B2" ref-type="bibr">2</xref>
], and 2009 (Novel swine-origin influenza A (H1N1) virus investigation team, 2009) pandemic influenza viruses and may expectably play a similar role in the creation of future pandemic viruses. In addition, on multiple occasions, it has been evident that avian influenza viruses (AIVs), chiefly the subtypes H5N1, H7N7, and H9N2, directly transmitted from birds to humans [
<xref rid="B3" ref-type="bibr">3</xref>
,
<xref rid="B4" ref-type="bibr">4</xref>
]. Avian-originated H1N1, H3N2, H5N1, and H9N2 viruses have been recovered from pigs in Asia, Europe, and Canada [
<xref rid="B5" ref-type="bibr">5</xref>
<xref rid="B7" ref-type="bibr">7</xref>
]. Furthermore, H2N3 avian virus reassortants were isolated from pigs in the United States [
<xref rid="B8" ref-type="bibr">8</xref>
].</p>
<p>Pigs have been postulated, hence, to be the ultimate “mixing vessels” for mammalian influenza viruses and AIVs and can play an important role in the genetic reassortment of influenza viruses. Therefore, detection and characterization of AIVs, especially those subtypes having the potential to transmit to mammals, including pigs and humans, are significant. Avian H7N7 and H3N8 strains are contracted and circulated by horses, as well, and an equine H3N8 virus apparently was involved in the formation of the pandemic H3N2 virus, and perhaps the H3N8 pandemic virus of 1889 [
<xref rid="B9" ref-type="bibr">9</xref>
]. </p>
<p>The genome of influenza A viruses consists of eight different segments of single-stranded negative-sense RNA. Most gene segments encode for one protein; whereas the gene segments 2 (polymerase basic1—PB1), 7 (matrix—M), and 8 (nonstructural—NS gene), each encodes one additional protein from alternatively spliced mRNA. Among the proteins, 9 are structural, while the rest two, namely PB1-F2 and NS1, are nonstructural. Thirteen genes have already been identified all over. Aquatic birds are the primary reservoir of type A influenza viruses and are classified into various antigenic subtypes, based on their two surface glycoproteins, the HA, and the NA. So far, seventeen HA (H1–H17) and nine NA subtypes (N1–N9) have been identified from avian species [
<xref rid="B10" ref-type="bibr">10</xref>
], representing the entire pool of influenza A viruses known today. Most of them are not found or uncommon within mammalian hosts. Although largely shaped by the HA, the virulence of influenza A viruses is polygenic in nature. H5 and H7 influenza viruses with multiple basic amino acids nearby to the cleavage site of the HA glycoprotein exhibit a wide range of tissue tropism and lead to systemic disease in chickens with fatality [
<xref rid="B11" ref-type="bibr">11</xref>
].</p>
<p>It has been demonstrated that the amino acids at positions 627 and 701 of the polymerase basic 2 (PB2) protein influence the outcome of infection in mice [
<xref rid="B12" ref-type="bibr">12</xref>
,
<xref rid="B13" ref-type="bibr">13</xref>
]. Several studies have reported that the NS1 protein is also associated with the virulence of influenza viruses [
<xref rid="B14" ref-type="bibr">14</xref>
,
<xref rid="B15" ref-type="bibr">15</xref>
]. The glutamic acid at position 92 of NS1 of H5N1 influenza virus confers virulence and resistance to antiviral cytokines in pigs [
<xref rid="B16" ref-type="bibr">16</xref>
]. In spite of those well-known, meaningful functions of the NS gene concerning virulence and escape from host cytokine response, the degree of variation in the NS gene pool of AIVs in their natural reservoirs, particularly in the Northern pintail (
<italic>Anas acuta</italic>
) (thereafter referred to as pintail (s)) ducks, a globally major influenza host wintering in Japan, is poorly studied. In this paper, we focused on genetic analysis of H1N1, H1N2, and H1N3 strains of AIVs that we isolated from apparently healthy migratory pintails wintering in Japan [
<xref rid="B17" ref-type="bibr">17</xref>
,
<xref rid="B18" ref-type="bibr">18</xref>
]. Also, we analyzed the NS genes of H5 and H7 subtypes, in addition to the above-mentioned AIVs. Moreover, polymerase acid (PA), nucleoprotein (NP), M, and NS genes of H5N9 strain, an uncommon antigenic combination which we isolate for the first time in Asia [
<xref rid="B19" ref-type="bibr">19</xref>
], were further looked into in the present study.</p>
</sec>
<sec id="sec2">
<title>2. Material and Methods</title>
<sec id="sec2.1">
<title>2.1. Viruses</title>
<p>Viruses used in this study (
<xref ref-type="table" rid="tab1">Table 1</xref>
) were of low pathogenicity and isolated in embryonated chicken eggs (ECE) from fecal materials of migratory, apparently healthy pintails wintering in Japan [
<xref rid="B17" ref-type="bibr">17</xref>
,
<xref rid="B18" ref-type="bibr">18</xref>
]. Working stocks of viruses were prepared by 3rd passage in ECE, and allantoic fluid was harvested at 3 days after inoculation (dpi) and stored at −80°C.</p>
</sec>
<sec id="sec2.2">
<title>2.2. RNA Extraction and RT-PCR</title>
<p>Total viral RNA was extracted from infected allantoic fluid using the Isogen-LS (Nippongene, Tokyo, Japan), in accordance with the manufacturer's instructions. Reverse transcription was carried out with the Uni12 primer (5′-AGC AAA AGC AAG G-3′) and MMLV reverse transcriptase (GeneAmp RNA PCR Kit, Applied Biosystems, Tokyo, Japan), followed by full length amplification of each gene segment, as described earlier [
<xref rid="B20" ref-type="bibr">20</xref>
]. The PCR product was purified using QIAquick Gel Extraction Kit (Qiagen, Valencia, CA), according to the manufacturer's instructions.</p>
</sec>
<sec id="sec2.3">
<title>2.3. Gene Sequencing</title>
<p>The PCR product was sequenced by dideoxy chain terminating method, using Dye Terminator Cycle Sequencing FS Ready Reaction Kit (Perkin-Elmer Applied Biosystems, Japan). Sequencing was carried out with the same primers used to amplify the gene and continued with subsequently designed sequence-specific primers. Nucleotide sequences were determined using an automated DNA sequencer (ABI 310 DNA sequencer, Applied Biosystems, Foster City, CA), edited and assembled with GENETYX-Mac (version 10.0; Software Development Corp., Tokyo, Japan).</p>
</sec>
<sec id="sec2.4">
<title>2.4. Sequence and Phylogenetic Analysis</title>
<p>Multiple sequence alignments and processing were performed with the Molecular Evolutionary Genetics Analysis (MEGA) version 4.1.0 software, with an engine based on the ClustalW algorithm [
<xref rid="B21" ref-type="bibr">21</xref>
]. Blast searches were used to retrieve the homologous sequences from the GenBank database. The phylogenetic analyses were performed using neighbor joining tree inference analysis, with the 1000 bootstrap replications, to assign confidence levels to branches. Nucleotide sequences of entire open reading frame (ORF) of each gene segment (except PB1 gene of A/northern pintail/Aomori/1130/08 H1N3 (Aomori/1130/08 H1N3)) were used in the phylogenetic analysis. The PB1 gene of Aomori/1130/08 H1N3 was partially 1350 base pair (1-1350 bp) sequenced and used in the phylogenetic analysis. Furthermore, the HA gene of A/northern pintail/Akita/1364/08 H1N2 (Akita/1364/08 H1N2) was sequenced partially 765 bp (760-1524) and was not included in the phylogenetic analysis.</p>
</sec>
<sec id="sec2.5">
<title>2.5. GenBank Accession Number</title>
<p>The nucleotide sequences generated in this study have been deposited in GenBank and are available under accession number AB546149–AB546193.</p>
</sec>
</sec>
<sec id="sec3">
<title>3. Results and Discussion</title>
<p>As a part of longitudinal virological studies, we have isolated various subtypes of AIVs from fecal materials of migratory, apparently healthy pintails wintering in Tohoku district, Japan [
<xref rid="B17" ref-type="bibr">17</xref>
,
<xref rid="B18" ref-type="bibr">18</xref>
]. Of these, H1N1, H1N2, and H1N3 viruses were characterized genetically. For phylogenetic relationships of NS gene, the latter from viruses bearing H1, H5, and H7 HA was sequenced and compared with viruses from GenBank.</p>
<sec id="sec3.1">
<title>3.1. Genetic and Phylogenetic Analysis of HA Genes</title>
<p>The sequenced HA genes (
<italic>n</italic>
= 6) of H1 subtype with different NA subtype combinations (N1, N2, and N3) isolated from pintails during 2007-2008 were closely related to each other (
<xref ref-type="fig" rid="fig1">Figure 1(a)</xref>
;
<xref ref-type="table" rid="tab2">Table 2</xref>
). The nucleotide and amino acid sequence identities were found to range from 96.5 to 100% and 98.0 to 100%, respectively. Phylogenetically, the viruses were clustered with the viruses from Eurasian countries, mostly with viruses from China, namely A/duck/Hebei/843/05 H1N2 and A/wild duck/JX/12416/05 H1N1 (>97% nucleotide homology) (
<xref ref-type="fig" rid="fig1">Figure 1(a)</xref>
). The HA genes of sequenced viruses were grouped into the h1.1.2 (subtype H1) [
<xref rid="B22" ref-type="bibr">22</xref>
]. Viruses of the present study had a sister group relationship with the Japanese H1 viruses including A/pintail/Shimane/324/98 H1N9 isolated earlier. North American strains, and swine, human seasonal and pandemic H1 strains integrated sharply in different branches. It means that although bearing the same antigenic subtype (H1N1) and obtained during 2007-2008, our isolates were unrelated to the porcine-derived 2009 pandemic and seasonal flu strains.</p>
</sec>
<sec id="sec3.2">
<title>3.2. Genetic and Phylogenetic Analysis of NA Genes</title>
<p>Like HA genes, the nucleotide homologies of the NA genes of the isolates with each other were 96.8–99.8% and 99.7–99.9% for N1 (
<italic>n</italic>
= 3) and N2 (
<italic>n</italic>
= 3), respectively, for each subtype. On the other hand, the amino acid sequence identities were found to range from 97.4 to 99.8% (N1) and 99.4–99.8% (N2). A duck-originated Japanese strain obtained 2 years earlier, A/duck/Tsukuba/67/05 H1N1 (Tsukuba/67/05 H1N1) was found most closely related to one of the isolates—A/northern pintail/Aomori/422/07 H1N1 (Aomori/422/07 H1N1) (>98% homology at both nucleotide and amino acid sequences)—of the present study, while two other viruses have maximum homology to a Mongolian strain, A/duck/Mongolia/116/02 H1N1 (Mongolia/116/02 H1N1), isolated in 2002 (>98% homology at both nucleotide and amino acid sequences). For N2 NAs, a Chinese strain, namely A/goose/Gui Yang/3799/05 H5N2 (Gui Yang/3799/05 H5N2) isolated from goose in 2005 was found rather closely related (>98% nucleotide and amino acid identity). The N3 NA gene of Aomori/1130/08 H1N3 has >99% nucleotide and amino acid homology to a duck strain, namely A/duck/Niigata/514/06 H5N3 (Niigata/514/06 H5N3) isolated in 2006 in Japan (
<xref ref-type="table" rid="tab3">Table 3</xref>
). Principally, the NA genes of the sequenced viruses were clustered with viruses of Eurasian origin (Figures
<xref ref-type="fig" rid="fig1">1(b)</xref>
and
<xref ref-type="fig" rid="fig1">1(c)</xref>
). More specifically they can be grouped into sublineages n1.1.8 (N1 subtype) and n2.1.6 (subtype N2) [
<xref rid="B22" ref-type="bibr">22</xref>
]. NA gene of Aomori/422/07 H1N1 strain branched separately from other strains isolated by us in 2008 (
<xref ref-type="fig" rid="fig1">Figure 1(b)</xref>
), the N2 NA genes of which were all integrated into a single branch represented by a H5N2 strain, Gui Yang/3799/05, which was isolated in China in 2005 (
<xref ref-type="fig" rid="fig1">Figure 1(c)</xref>
). Like H1 HA genes, the N1 NA genes were distinctly separated from pandemic strains (
<xref ref-type="fig" rid="fig1">Figure 1(b)</xref>
).</p>
</sec>
<sec id="sec3.3">
<title>3.3. Genetic and Phylogenetic Analysis of NS Genes</title>
<p>A remarkably diverse variation in the nucleotide sequence identities (50–100%) was found among the NS genes of the sequenced viruses (
<xref ref-type="table" rid="tab4">Table 4</xref>
). When analyzed phylogenetically, they were distinctly branched into two branches, allele A and B [
<xref rid="B23" ref-type="bibr">23</xref>
], and clustered with Eurasian origin viruses (
<xref ref-type="fig" rid="fig1">Figure 1(d)</xref>
and
<xref ref-type="table" rid="tab4">Table 4</xref>
). Nucleotide sequence identities of NS genes within allele A and within allele B were 97.7–100% and 94.4–100%, respectively. However, the divergence between the two alleles was approximately 50%, regardless of their isolation time and geographical location. The majority of the viruses of the present study were branched with allele A viruses represented with/by A/mallard/Sweden/2724/06 H5N1 and A/duck/Hong Kong/Y439/97 H9N2 (Hong Kong/Y439/97 H9N2). In contrast, A/northern pintail/Aomori/372/08 H7N7 (Aomori/372/08 H7N7), Aomori/385/08 H5N3, and A/northern pintail/Miyagi/674/08 H7N7 (Miyagi/674/08 H7N7) viruses were clustered with allele B viruses represented with/by A/goose/Guangdong/1/96 H5N1 (Guangdong/1/96 H5N1). As for allele A, two pairs—Akita/1256/07 H5N2 and Akita/1355/07 H5N2, alongside with Akita/1353/08 H1N2 and Akita/1364/08 H1N2 viruses—were found 100% homologous, while in allele B Aomori/372/08 H7N7 and Miyagi/674/08 H7N7 viruses were found to be entirely identical.</p>
<p>Significantly, the NS1 genes of influenza viruses in general have been divided into two alleles: A and B [
<xref rid="B23" ref-type="bibr">23</xref>
]. Regardless of some exceptions, all influenza viruses circulating in mammalian species and many viruses from avian species comprise the allele A, while allele B is found within only AIVs. The NS1 gene of the majority of highly pathogenic avian influenza (HPAI) H5N1 viruses isolated from humans since 1997 is affiliated with allele A. In contrast, the NS1 gene of the Guangdong/1/96 virus, which was the source of the initial HPAI H5N1/1997 HA gene, belonged to allele B [
<xref rid="B24" ref-type="bibr">24</xref>
]. The NS1 genes of viruses of the present study—all LPAI—belong either to allele A or allele B. Curiously, it was pointed out that some strains of the HPAI H5N1 virus were preserved genetically unchanged from 1997 up to 2005 [
<xref rid="B25" ref-type="bibr">25</xref>
]. In that connection, perhaps, it is of note that the NS gene of some viruses, for example Aomori/372/08 H7N7 and Miyagi/674/08 H7N7 of this study have only <3% nucleotide disparity from that of a Russian strain, namely A/duck/Chabarovsk/1610/72 H3N8 (Chabarovsk/1610/72 H3N8), isolated in 1972. The NS gene of one of the viruses we had isolated from pintail ducks, namely Akita/714/06 H5N2, has 98.3% nucleotide homology to the same Russian isolate Chabarovsk/1610/72 H3N8 [
<xref rid="B26" ref-type="bibr">26</xref>
]. It means that the ongoing mutation rate during about 35 years was only about 1.7%, which is markedly less than the expected one. This may imply that throughout about a third of that 35 years period the NS gene has been somehow conserved, considering that the estimated NS gene evolutionary rates for avian, classic swine, and equine lineages are 0.84–1.27 nucleotide changes per site per year [
<xref rid="B27" ref-type="bibr">27</xref>
], and even higher, within both wild and domestic avian host species [
<xref rid="B28" ref-type="bibr">28</xref>
]. Basically, the two reasons thought to possibly account for unexplained genetic conservation in influenza A viruses are cross contamination, or interference with vaccine strains [
<xref rid="B29" ref-type="bibr">29</xref>
]. The strain Chabarovsk/1610/72 or related strains are not held in our laboratory, and interference with a vaccine strain seems unlikely, in that case. Abiotic environmental virus preservation has been suggested as an alternative explanation [
<xref rid="B30" ref-type="bibr">30</xref>
]. These, together with the location of Chabarovsk being close to the regular migration route of pintails between Japan and Siberia, have to further be looked into. </p>
<p>Prevalence of allele A and B viruses in their natural hosts has been reported to vary spatially, as well. Generally, allele B viruses were reported to be less common in their natural hosts than allele A. Out of 11 NS genes sequenced in this study, 72.7% (8/11) were classified as allele A, and 27.3% (3/11) as allele B. In Asia, the prevalence of allele B viruses in all avian species has been reported to be only 15% [
<xref rid="B31" ref-type="bibr">31</xref>
], which is markedly lower than found in this study. However, the prevalence rate of allele B viruses in North American free flying birds has been documented to be 30%, similar to that observed in pintails in our study [
<xref rid="B32" ref-type="bibr">32</xref>
], but higher than found in Northern European mallards (13%; 6 out of 45) [
<xref rid="B31" ref-type="bibr">31</xref>
]. This might be due to the migration pattern of pintails sampled in our study. Most pintails which winter in Japan originate from eastern Russia [
<xref rid="B33" ref-type="bibr">33</xref>
,
<xref rid="B34" ref-type="bibr">34</xref>
]. Besides, pintails marked in North America have been recovered during winter in Japan and vice versa [
<xref rid="B35" ref-type="bibr">35</xref>
,
<xref rid="B36" ref-type="bibr">36</xref>
]. Moreover, some pintails migrate from North America to eastern Russia [
<xref rid="B37" ref-type="bibr">37</xref>
], where they could come into contact with birds that migrate from six continents, including Asian wintering sites [
<xref rid="B38" ref-type="bibr">38</xref>
]. Furthermore, from the recent satellite telemetry data, provided by the United States Geological Survey (USGS) and the US Fish and Wildlife Service, it is evident that pintails marked during winter in Japan move to Alaska through Russia and return to Japan, following the same route (Alaska Science Center, Movements of Northern Pintail ducks and Whooper Swans marked with satellite transmitters in Japan
<ext-link ext-link-type="uri" xlink:href="http://alaska.usgs.gov/science/biology/avian_influenza/pintail_movements_virus.php">http://alaska.usgs.gov/science/biology/avian_influenza/pintail_movements_virus.php</ext-link>
. Thus, inter- and intra continental exchange of genes and genomes of AIV could occur through congregation of North American and Asian migrants at shared summer habitats in eastern Russia, or by means of pintails that migrate between North American nesting grounds and Japanese wintering grounds (assessment of virus movement across continents: using Northern Pintails (Anas acuta) as a test.
<ext-link ext-link-type="uri" xlink:href="http://alaska.usgs.gov/science/biology/avian_influenza/migration_ecology.php">http://alaska.usgs.gov/science/biology/avian_influenza/migration_ecology.php</ext-link>
. Also the number of samples may possibly have effect on the results found in this study.</p>
</sec>
<sec id="sec3.4">
<title>3.4. Genetic and Phylogenetic Analysis of NP Genes</title>
<p>The NP genes of the sequenced viruses have 90.4–99.9% nucleotide homologies among each other, regardless of their temporal and spatial differences in isolation (
<xref ref-type="table" rid="tab5">Table 5</xref>
). Broadly, viruses isolated from Eastern Hemisphere have high homologies to the NP genes of the viruses of this study (97.2 to 99.5% nucleotide identity). It is noteworthy that the NP gene of the majority of viruses (75% of 8 viruses) investigated in this study had a high homology to a porcine strain, namely A/swine/Korea/C12/08 H5N2 (Korea/C12/08 H5N2) isolated in 2008, suggesting that the NP genes of these viruses and the Korea isolate might have a common ancestral origin. Similar to NP gene of H1 viruses, the HA genes of some H5N2 viruses isolated by us during 2006-2007 were found to be closely related to this Korean virus [
<xref rid="B19" ref-type="bibr">19</xref>
,
<xref rid="B26" ref-type="bibr">26</xref>
]. In conjunction, biogeographically and phylogenetically, other related strains, namely A/garganey/San Jiang/160/06 H5N2, A/baikal teal/Hongze/14/05 H11N9, and A/duck/Hong Kong/MPS180/03 H4N6 originated from China, and one strain, A/mallard/Hokkaido/24/09 H5N1, from Japan. For NP gene viruses from both Eurasian countries and North America were clustered with the viruses of the present study (
<xref ref-type="fig" rid="fig1">Figure 1(e)</xref>
). The nucleotide sequence disparity between viruses of this study and North American viruses clustered together ranged from 1.4 to 9.3%. Especially, and not by chance, in all likelihood, Aomori/422/07 H1N1 has 98.6% nucleotide identity to the strain A/pintail/Alaska/1/07 H3N8, meaning isolated from the same host in the same year. In that case, viruses of North American lineage integrated distinctly from those of Eurasian lineage, suggesting, in light of the mentioned high NP gene homology, intercontinental gene exchange through reassortment, rather than whole genome intercontinental conveyance. Such interfaces are at any rate significant, evolutionarily and epidemiologically.</p>
</sec>
<sec id="sec3.5">
<title>3.5. Molecular Features of HA and NA</title>
<p>The HA amino acid sequences deduced from nucleotide sequences analysis revealed that all the viruses contain seven potential N-linked glycosylation sites (5 in HA1 and 2 in HA2) throughout the HA molecule. Except for Aomori/422/07 H1N1, the amino acid motif of the HA0 cleavage site of all the sequenced H1 viruses was PSIQSR*GLF (*cleavage point), which is common in all avian, porcine, and human viruses. Aomori/422/07 H1N1 contains a rare amino acid motif, PSVQSR*GLF. Among the H1 avian strains isolated globally and sequences reported in GenBank during 1980–2009, only one strain, namely A/mallard/New York/170/82 H1N2 has identical (PSVQSR*GLF) amino acids. However, Aomori/422/07 H1N1 solely clustered with the Eurasian viruses (
<xref ref-type="fig" rid="fig1">Figure 1(a)</xref>
), implying, ostensibly that it has no relation with the mallard-originated New York strain and evolves individually. Still, the extreme rareness of the mentioned motif might possibly be supportive of genetic recombination event that perhaps took place within collocated ducks from North America and Asia. The HA molecules of all of the sequenced H1 viruses contain residues Gln (Q) and Gly (G) at positions 240 and 242 (H1 numbering), respectively, which indicate the avian receptor specificity.</p>
<p>On the other hand, the amino acid sequence analysis of NAs revealed that all the viruses contain full length NA protein with seven potential N-linked glycosylation sites in N1 and N2 known to be conserved in wild ducks [
<xref rid="B39" ref-type="bibr">39</xref>
]. In all NA molecules, a residue His (H) was found at position 274 (N2 numbering), thereby indicating sensitivity to Oseltamivir or Zamamivir [
<xref rid="B40" ref-type="bibr">40</xref>
]. Besides, typical catalytic sites, framework sites as well as other specific regions were found completely conserved as described previously [
<xref rid="B41" ref-type="bibr">41</xref>
]. Residue position 198 in N3 NA contains Asn (N) instead of Asp (D) and is also shown to be conserved [
<xref rid="B41" ref-type="bibr">41</xref>
]. The N1 and N2 NA of the sequenced viruses possessed E119 and R292 amino acid residues, indicating that the commonly mutated residues in NA inhibitor-resistant viruses were not present [
<xref rid="B42" ref-type="bibr">42</xref>
].</p>
</sec>
<sec id="sec3.6">
<title>3.6. Molecular Features of NS1</title>
<p>Deletion of several amino acids in the NS1 gene has been observed more frequently in AIVs in recent years, a feature of possible adaptation of these viruses to poultry [
<xref rid="B24" ref-type="bibr">24</xref>
,
<xref rid="B43" ref-type="bibr">43</xref>
]. The viruses sequenced in our study contained full length NS genes, indicating basically wild bird strains. Nevertheless, all isolates possessed residue Ala (A) position 149, which is important for replication of viruses in chickens [
<xref rid="B24" ref-type="bibr">24</xref>
]. Also, residue Asp (D) instead of Glu (E) was found at position 92 of the NS1, which is reported to be involved in modulation of cytokine response, and has been associated with the high virulence exhibited by HPAI H5N1 viruses in pigs [
<xref rid="B16" ref-type="bibr">16</xref>
]. All the sequenced viruses contain a PDZ (postsynaptic density,
<underline>P</underline>
SD-95; discs large, Dlg; zonula occludens-1,
<underline>Z</underline>
O-1) domain ligand at the C terminus of NS1 (ESEV-COOH), which plays an important role in many key signaling pathways of viral replication [
<xref rid="B44" ref-type="bibr">44</xref>
].</p>
</sec>
<sec id="sec3.7">
<title>3.7. Relation between Avian H1N1 Strains and Pandemic and Seasonal Influenza Strains</title>
<p>When compared to pandemic and seasonal influenza viruses, the HA genes' nucleotide identity of viruses of the present study was found to range from 67.1 to 76.4%, while amino acid sequence homology was found 81.8–92.1% (
<xref ref-type="table" rid="tab6">Table 6</xref>
). In difference, for NA gene, a somewhat higher nucleotide and amino acid identity was found (79.3–86.5% nucleotide and 84.9–92.5% amino acid sequence identities). Not only the HA and NA genes but also other internal genes of pandemic and seasonal flu strains were clustered distinctly from those of our isolates, suggesting no relation between these viruses. Basically, genomic analyses of the last four pandemic strains showed that the genes contributed by avian strains are those that encode for the polymerases and surface antigens, as follows:1918—PB1 and PA; 1957—PB1, HA, and NA; 1968—PB1 and HA; 2009—PB2 and PA. This means that among the presently prevailing pandemic and seasonal strains, only the seasonal H3N2 has past affinity to avian HA, when it originally formed as a then pandemic strain in 1968, thereafter considerably drifting genetically for already 43 years. Independent drift probably took place during that period of time within the precursor avian H3 HA gene in bird populations.</p>
</sec>
</sec>
<sec id="sec4">
<title>4. Conclusion</title>
<p>In conclusion, our genetic analysis suggests that the sequenced viruses were to an appreciable degree characteristic of the pintail populations we sampled, which typically winter in Japan. Except in one strain, the HA0 cleavage site of H1 was found as usually found in all avian, porcine, and human viruses. The residues that compose the catalytic and framework sites of the NA enzyme were completely conserved in the studied viruses. The NP gene of the majority of the strains sequenced in this study (5/8) was related to that of the porcine strain Korea/C12/08 H5N2. Thus, it may be presumed that our isolates evolved through reassortment process during the cocirculation of these strains. Our findings clearly demonstrate that two distinct gene pools, corresponding to both NS allele A and B, were present within the pintail populations wintering in Japan. It is noteworthy that some strains contain NS gene highly related to a duck isolate obtained in Russian in 1972, about 35 years prior to our isolate, indicating significant gene conservation. It is also concluded that although bearing the same antigenic subtype (H1N1) and obtained during 2007-2008, our isolates were unrelated to 2009 pandemic and seasonal flu strains. </p>
</sec>
</body>
<back>
<ref-list>
<ref id="B1">
<label>1</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Campitelli</surname>
<given-names>L</given-names>
</name>
<name>
<surname>Fabiani</surname>
<given-names>C</given-names>
</name>
<name>
<surname>Puzelli</surname>
<given-names>S</given-names>
</name>
<etal></etal>
</person-group>
<article-title>H3N2 influenza viruses from domestic chickens in Italy: an increasing role for chickens in the ecology of influenza?</article-title>
<source>
<italic>Journal of General Virology</italic>
</source>
<year>2002</year>
<volume>83</volume>
<issue>2</issue>
<fpage>413</fpage>
<lpage>420</lpage>
<pub-id pub-id-type="other">2-s2.0-0036171472</pub-id>
<pub-id pub-id-type="pmid">11807234</pub-id>
</element-citation>
</ref>
<ref id="B2">
<label>2</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Kawaoka</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Krauss</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
</person-group>
<article-title>Avian-to-human transmission of the PB1 gene of influenza A viruses in the 1957 and 1968 pandemics</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>1989</year>
<volume>63</volume>
<issue>11</issue>
<fpage>4603</fpage>
<lpage>4608</lpage>
<pub-id pub-id-type="other">2-s2.0-0024439330</pub-id>
<pub-id pub-id-type="pmid">2795713</pub-id>
</element-citation>
</ref>
<ref id="B3">
<label>3</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Claas</surname>
<given-names>ECJ</given-names>
</name>
<name>
<surname>Osterhaus</surname>
<given-names>ADME</given-names>
</name>
<name>
<surname>Van Beek</surname>
<given-names>R</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Human influenza A H5N1 virus related to a highly pathogenic avian influenza virus</article-title>
<source>
<italic>Lancet</italic>
</source>
<year>1998</year>
<volume>351</volume>
<issue>9101</issue>
<fpage>472</fpage>
<lpage>477</lpage>
<pub-id pub-id-type="other">2-s2.0-0032515638</pub-id>
<pub-id pub-id-type="pmid">9482438</pub-id>
</element-citation>
</ref>
<ref id="B4">
<label>4</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Lin</surname>
<given-names>YP</given-names>
</name>
<name>
<surname>Shaw</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Gregory</surname>
<given-names>V</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Avian-to-human transmission of H9N2 subtype influenza A viruses: relationship between H9N2 and H5N1 human isolates</article-title>
<source>
<italic>Proceedings of the National Academy of Sciences of the United States of America</italic>
</source>
<year>2000</year>
<volume>97</volume>
<issue>17</issue>
<fpage>9654</fpage>
<lpage>9658</lpage>
<pub-id pub-id-type="other">2-s2.0-12944270582</pub-id>
<pub-id pub-id-type="pmid">10920197</pub-id>
</element-citation>
</ref>
<ref id="B5">
<label>5</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Guan</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Shortridge</surname>
<given-names>KF</given-names>
</name>
<name>
<surname>Krauss</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Li</surname>
<given-names>PH</given-names>
</name>
<name>
<surname>Kawaoka</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
</person-group>
<article-title>Emergence of avian H1N1 influenza viruses in pigs in China</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>1996</year>
<volume>70</volume>
<issue>11</issue>
<fpage>8041</fpage>
<lpage>8046</lpage>
<pub-id pub-id-type="other">2-s2.0-0029846229</pub-id>
<pub-id pub-id-type="pmid">8892928</pub-id>
</element-citation>
</ref>
<ref id="B6">
<label>6</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Karasin</surname>
<given-names>AI</given-names>
</name>
<name>
<surname>West</surname>
<given-names>K</given-names>
</name>
<name>
<surname>Carman</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Olsen</surname>
<given-names>CW</given-names>
</name>
</person-group>
<article-title>Characterization of avian H3N3 and H1N1 influenza A viruses isolated from pigs in Canada</article-title>
<source>
<italic>Journal of Clinical Microbiology</italic>
</source>
<year>2004</year>
<volume>42</volume>
<issue>9</issue>
<fpage>4349</fpage>
<lpage>4354</lpage>
<pub-id pub-id-type="other">2-s2.0-4644324869</pub-id>
<pub-id pub-id-type="pmid">15365042</pub-id>
</element-citation>
</ref>
<ref id="B7">
<label>7</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Peiris</surname>
<given-names>JSM</given-names>
</name>
<name>
<surname>Guan</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Markwell</surname>
<given-names>D</given-names>
</name>
<name>
<surname>Ghose</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
<name>
<surname>Shortridge</surname>
<given-names>KF</given-names>
</name>
</person-group>
<article-title>Cocirculation of avian H9N2 and contemporary “human” H3N2 influenza A viruses in pigs in southeastern China: potential for genetic reassortment?</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>2001</year>
<volume>75</volume>
<issue>20</issue>
<fpage>9679</fpage>
<lpage>9686</lpage>
<pub-id pub-id-type="other">2-s2.0-0034815075</pub-id>
<pub-id pub-id-type="pmid">11559800</pub-id>
</element-citation>
</ref>
<ref id="B8">
<label>8</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Ma</surname>
<given-names>W</given-names>
</name>
<name>
<surname>Vincent</surname>
<given-names>AL</given-names>
</name>
<name>
<surname>Gramer</surname>
<given-names>MR</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Identification of H2N3 influenza A viruses from swine in the United States</article-title>
<source>
<italic>Proceedings of the National Academy of Sciences of the United States of America</italic>
</source>
<year>2007</year>
<volume>104</volume>
<issue>52</issue>
<fpage>20949</fpage>
<lpage>20954</lpage>
<pub-id pub-id-type="other">2-s2.0-38049173100</pub-id>
<pub-id pub-id-type="pmid">18093945</pub-id>
</element-citation>
</ref>
<ref id="B9">
<label>9</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Shoham</surname>
<given-names>D</given-names>
</name>
</person-group>
<article-title>The modes of evolutionary emergence of primal and late pandemic influenza virus strains from viral reservoir in animals: an interdisciplinary analysis</article-title>
<source>
<italic>Influenza Research and Treatment</italic>
</source>
<year>2011</year>
<volume>2011</volume>
<fpage>27 pages</fpage>
<pub-id pub-id-type="publisher-id">861792</pub-id>
</element-citation>
</ref>
<ref id="B10">
<label>10</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Tong</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Li</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Rivailler</surname>
<given-names>P</given-names>
</name>
<etal></etal>
</person-group>
<article-title>A distinct lineage of influenza A virus from bats</article-title>
<source>
<italic>Proceedings of the National Academy of Sciences of the United States of America</italic>
</source>
<year>2012</year>
<volume>109</volume>
<fpage>4269</fpage>
<lpage>4274</lpage>
<pub-id pub-id-type="pmid">22371588</pub-id>
</element-citation>
</ref>
<ref id="B11">
<label>11</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Kawaoka</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
</person-group>
<article-title>Sequence requirements for cleavage activation of influenza virus hemagglutinin expressed in mammalian cells</article-title>
<source>
<italic>Proceedings of the National Academy of Sciences of the United States of America</italic>
</source>
<year>1988</year>
<volume>85</volume>
<issue>2</issue>
<fpage>324</fpage>
<lpage>328</lpage>
<pub-id pub-id-type="other">2-s2.0-0023736676</pub-id>
<pub-id pub-id-type="pmid">2829180</pub-id>
</element-citation>
</ref>
<ref id="B12">
<label>12</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Hatta</surname>
<given-names>H</given-names>
</name>
<name>
<surname>Gao</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Halfmann</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Kawaoka</surname>
<given-names>Y</given-names>
</name>
</person-group>
<article-title>Molecular basis for high virulence of Hong Kong H5N1 influenza a viruses</article-title>
<source>
<italic>Science</italic>
</source>
<year>2001</year>
<volume>293</volume>
<issue>5536</issue>
<fpage>1840</fpage>
<lpage>1842</lpage>
<pub-id pub-id-type="other">2-s2.0-0035823083</pub-id>
<pub-id pub-id-type="pmid">11546875</pub-id>
</element-citation>
</ref>
<ref id="B13">
<label>13</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Li</surname>
<given-names>Z</given-names>
</name>
<name>
<surname>Chen</surname>
<given-names>H</given-names>
</name>
<name>
<surname>Jiao</surname>
<given-names>P</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Molecular basis of replication of duck H5N1 influenza viruses in a mammalian mouse model</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>2005</year>
<volume>79</volume>
<issue>18</issue>
<fpage>12058</fpage>
<lpage>12064</lpage>
<pub-id pub-id-type="other">2-s2.0-24644484686</pub-id>
<pub-id pub-id-type="pmid">16140781</pub-id>
</element-citation>
</ref>
<ref id="B14">
<label>14</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Li</surname>
<given-names>Z</given-names>
</name>
<name>
<surname>Jiang</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Jiao</surname>
<given-names>P</given-names>
</name>
<etal></etal>
</person-group>
<article-title>The NS1 gene contributes to the virulence of H5N1 avian influenza viruses</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>2006</year>
<volume>80</volume>
<issue>22</issue>
<fpage>11115</fpage>
<lpage>11123</lpage>
<pub-id pub-id-type="other">2-s2.0-33750719489</pub-id>
<pub-id pub-id-type="pmid">16971424</pub-id>
</element-citation>
</ref>
<ref id="B15">
<label>15</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Noah</surname>
<given-names>DL</given-names>
</name>
<name>
<surname>Twu</surname>
<given-names>KY</given-names>
</name>
<name>
<surname>Krug</surname>
<given-names>RM</given-names>
</name>
</person-group>
<article-title>Cellular antiviral responses against influenza A virus are countered at the posttranscriptional level by the viral NS1A protein via its binding to a cellular protein required for the 3′ end processing of cellular pre-mRNAS</article-title>
<source>
<italic>Virology</italic>
</source>
<year>2003</year>
<volume>307</volume>
<issue>2</issue>
<fpage>386</fpage>
<lpage>395</lpage>
<pub-id pub-id-type="other">2-s2.0-0037444193</pub-id>
<pub-id pub-id-type="pmid">12667806</pub-id>
</element-citation>
</ref>
<ref id="B16">
<label>16</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Seo</surname>
<given-names>SH</given-names>
</name>
<name>
<surname>Hoffmann</surname>
<given-names>E</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
</person-group>
<article-title>Lethal H5N1 influenza viruses escape host anti-viral cytokine responses</article-title>
<source>
<italic>Nature Medicine</italic>
</source>
<year>2002</year>
<volume>8</volume>
<issue>9</issue>
<fpage>950</fpage>
<lpage>954</lpage>
<pub-id pub-id-type="other">2-s2.0-0036734038</pub-id>
</element-citation>
</ref>
<ref id="B17">
<label>17</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Jahangir</surname>
<given-names>A</given-names>
</name>
<name>
<surname>Watanabe</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Chinen</surname>
<given-names>O</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Surveillance of avian influenza viruses in Northern pintails (
<italic>Anas acuta</italic>
) in Tohoku District, Japan</article-title>
<source>
<italic>Avian Diseases</italic>
</source>
<year>2008</year>
<volume>52</volume>
<issue>1</issue>
<fpage>49</fpage>
<lpage>53</lpage>
<pub-id pub-id-type="other">2-s2.0-41849108032</pub-id>
<pub-id pub-id-type="pmid">18459295</pub-id>
</element-citation>
</ref>
<ref id="B18">
<label>18</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Jahangir</surname>
<given-names>A</given-names>
</name>
<name>
<surname>Ruenphet</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Ueda</surname>
<given-names>S</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Avian influenza and Newcastle disease viruses from northern pintail in Japan: isolation, characterization and inter-annual comparisons during 2006–2008</article-title>
<source>
<italic>Virus Research</italic>
</source>
<year>2009</year>
<volume>143</volume>
<issue>1</issue>
<fpage>44</fpage>
<lpage>52</lpage>
<pub-id pub-id-type="other">2-s2.0-67349264570</pub-id>
<pub-id pub-id-type="pmid">19463720</pub-id>
</element-citation>
</ref>
<ref id="B19">
<label>19</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Jahangir</surname>
<given-names>A</given-names>
</name>
<name>
<surname>Ruenphet</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Shoham</surname>
<given-names>D</given-names>
</name>
<name>
<surname>Okamura</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Nakamaura</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Takehara</surname>
<given-names>K</given-names>
</name>
</person-group>
<article-title>Haemagglutinin and neuraminidase characterization of low pathogenic H5 and H7 avian influenza viruses isolated from Northern pintails (
<italic>Anas acuta</italic>
) in Japan, with special reference to genomic and biogeographical aspects</article-title>
<source>
<italic>Virus Genes</italic>
</source>
<year>2010</year>
<volume>40</volume>
<issue>1</issue>
<fpage>94</fpage>
<lpage>105</lpage>
<pub-id pub-id-type="other">2-s2.0-77149165091</pub-id>
<pub-id pub-id-type="pmid">19916042</pub-id>
</element-citation>
</ref>
<ref id="B20">
<label>20</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Hoffmann</surname>
<given-names>E</given-names>
</name>
<name>
<surname>Stech</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Guan</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Webster</surname>
<given-names>RG</given-names>
</name>
<name>
<surname>Perez</surname>
<given-names>DR</given-names>
</name>
</person-group>
<article-title>Universal primer set for the full-length amplification of all influenza A viruses</article-title>
<source>
<italic>Archives of Virology</italic>
</source>
<year>2001</year>
<volume>146</volume>
<issue>12</issue>
<fpage>2275</fpage>
<lpage>2289</lpage>
<pub-id pub-id-type="other">2-s2.0-0035559445</pub-id>
<pub-id pub-id-type="pmid">11811679</pub-id>
</element-citation>
</ref>
<ref id="B21">
<label>21</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Tamura</surname>
<given-names>K</given-names>
</name>
<name>
<surname>Dudley</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Nei</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Kumar</surname>
<given-names>S</given-names>
</name>
</person-group>
<article-title>MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0</article-title>
<source>
<italic>Molecular Biology and Evolution</italic>
</source>
<year>2007</year>
<volume>24</volume>
<issue>8</issue>
<fpage>1596</fpage>
<lpage>1599</lpage>
<pub-id pub-id-type="other">2-s2.0-34547781750</pub-id>
<pub-id pub-id-type="pmid">17488738</pub-id>
</element-citation>
</ref>
<ref id="B22">
<label>22</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Liu</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Ji</surname>
<given-names>K</given-names>
</name>
<name>
<surname>Chen</surname>
<given-names>J</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Panorama phylogenetic diversity and distribution of type A influenza virus</article-title>
<source>
<italic>PLoS ONE</italic>
</source>
<year>2009</year>
<volume>4</volume>
<issue>3</issue>
<pub-id pub-id-type="other">2-s2.0-63449119902</pub-id>
<pub-id pub-id-type="publisher-id">e5022</pub-id>
</element-citation>
</ref>
<ref id="B23">
<label>23</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Ludwig</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Schultz</surname>
<given-names>U</given-names>
</name>
<name>
<surname>Mandler</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Fitch</surname>
<given-names>WM</given-names>
</name>
<name>
<surname>Scholtissek</surname>
<given-names>C</given-names>
</name>
</person-group>
<article-title>Phylogenetic relationship of the nonstructural (NS) genes of influenza A viruses</article-title>
<source>
<italic>Virology</italic>
</source>
<year>1991</year>
<volume>183</volume>
<issue>2</issue>
<fpage>566</fpage>
<lpage>577</lpage>
<pub-id pub-id-type="other">2-s2.0-0025914886</pub-id>
<pub-id pub-id-type="pmid">1830182</pub-id>
</element-citation>
</ref>
<ref id="B24">
<label>24</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Zohari</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Gyarmati</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Thorén</surname>
<given-names>P</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Genetic characterization of the NS gene indicates co-circulation of two sub-lineages of highly pathogenic avian influenza virus of H5N1 subtype in Northern Europe in 2006</article-title>
<source>
<italic>Virus Genes</italic>
</source>
<year>2008</year>
<volume>36</volume>
<issue>1</issue>
<fpage>117</fpage>
<lpage>125</lpage>
<pub-id pub-id-type="other">2-s2.0-39049146010</pub-id>
<pub-id pub-id-type="pmid">18172752</pub-id>
</element-citation>
</ref>
<ref id="B25">
<label>25</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Li</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Lin</surname>
<given-names>Z</given-names>
</name>
<name>
<surname>Shi</surname>
<given-names>J</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Detection of Hong Kong 97-like H5N1 influenza viruses from eggs of Vietnamese waterfowl</article-title>
<source>
<italic>Archives of Virology</italic>
</source>
<year>2006</year>
<volume>151</volume>
<issue>8</issue>
<fpage>1615</fpage>
<lpage>1624</lpage>
<pub-id pub-id-type="other">2-s2.0-33746167756</pub-id>
<pub-id pub-id-type="pmid">16532371</pub-id>
</element-citation>
</ref>
<ref id="B26">
<label>26</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Jahangir</surname>
<given-names>A</given-names>
</name>
<name>
<surname>Ruenphet</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Shoham</surname>
<given-names>D</given-names>
</name>
<name>
<surname>Okamura</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Nakamaura</surname>
<given-names>M</given-names>
</name>
<name>
<surname>Takehara</surname>
<given-names>K</given-names>
</name>
</person-group>
<article-title>Phenotypic, genetic, and phylogeographical characterization of avian influenza virus subtype H5N2 isolated from northern pintail (
<italic>Anas acuta</italic>
) in Japan</article-title>
<source>
<italic>Virus Research</italic>
</source>
<year>2009</year>
<volume>145</volume>
<issue>2</issue>
<fpage>329</fpage>
<lpage>333</lpage>
<pub-id pub-id-type="other">2-s2.0-70349233768</pub-id>
<pub-id pub-id-type="pmid">19635509</pub-id>
</element-citation>
</ref>
<ref id="B27">
<label>27</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Kawaoka</surname>
<given-names>Y</given-names>
</name>
<name>
<surname>Gorman</surname>
<given-names>OT</given-names>
</name>
<name>
<surname>Ito</surname>
<given-names>T</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Influence of host species on the evolution of the nonstructural (NS) gene of influenza A viruses</article-title>
<source>
<italic>Virus Research</italic>
</source>
<year>1998</year>
<volume>55</volume>
<issue>2</issue>
<fpage>143</fpage>
<lpage>156</lpage>
<pub-id pub-id-type="other">2-s2.0-0032104647</pub-id>
<pub-id pub-id-type="pmid">9725667</pub-id>
</element-citation>
</ref>
<ref id="B28">
<label>28</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Chen</surname>
<given-names>R</given-names>
</name>
<name>
<surname>Holmes</surname>
<given-names>EC</given-names>
</name>
</person-group>
<article-title>Avian influenza virus exhibits rapid evolutionary dynamics</article-title>
<source>
<italic>Molecular Biology and Evolution</italic>
</source>
<year>2006</year>
<volume>23</volume>
<fpage>2336</fpage>
<lpage>2341</lpage>
<pub-id pub-id-type="pmid">16945980</pub-id>
</element-citation>
</ref>
<ref id="B29">
<label>29</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Duan</surname>
<given-names>L</given-names>
</name>
<name>
<surname>Campitelli</surname>
<given-names>L</given-names>
</name>
<name>
<surname>Fan</surname>
<given-names>XH</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Characterization of low-pathogenic H5 subtype influenza viruses from Eurasia: implications for the origin of highly pathogenic H5N1 viruses</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>2007</year>
<volume>81</volume>
<issue>14</issue>
<fpage>7529</fpage>
<lpage>7539</lpage>
<pub-id pub-id-type="other">2-s2.0-34447272239</pub-id>
<pub-id pub-id-type="pmid">17507485</pub-id>
</element-citation>
</ref>
<ref id="B30">
<label>30</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Shoham</surname>
<given-names>D</given-names>
</name>
</person-group>
<article-title>Biotic-abiotic mechanisms for long-term preservation and reemergence of influenza type A virus genes</article-title>
<source>
<italic>Progress in Medical Virology</italic>
</source>
<year>1993</year>
<volume>40</volume>
<fpage>178</fpage>
<lpage>192</lpage>
<pub-id pub-id-type="other">2-s2.0-0027345386</pub-id>
</element-citation>
</ref>
<ref id="B31">
<label>31</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Zohari</surname>
<given-names>S</given-names>
</name>
<name>
<surname>Gyarmati</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Ejdersund</surname>
<given-names>A</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Phylogenetic analysis of the non-structural (NS) gene of influenza A viruses isolated from mallards in Northern Europe in 2005</article-title>
<source>
<italic>Virology Journal</italic>
</source>
<year>2008</year>
<volume>5, article 147</volume>
</element-citation>
</ref>
<ref id="B32">
<label>32</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Spackman</surname>
<given-names>E</given-names>
</name>
<name>
<surname>Stallknecht</surname>
<given-names>DE</given-names>
</name>
<name>
<surname>Slemons</surname>
<given-names>RD</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Phylogenetic analyses of type A influenza genes in natural reservoir species in North America reveals genetic variation</article-title>
<source>
<italic>Virus Research</italic>
</source>
<year>2005</year>
<volume>114</volume>
<issue>1-2</issue>
<fpage>89</fpage>
<lpage>100</lpage>
<pub-id pub-id-type="other">2-s2.0-27744502707</pub-id>
<pub-id pub-id-type="pmid">16039745</pub-id>
</element-citation>
</ref>
<ref id="B33">
<label>33</label>
<element-citation publication-type="book">
<collab>Yamashina Institute for Ornithology</collab>
<source>
<italic>Japanese Bird Banding in Recent Years (1961–1985)</italic>
</source>
<year>1985</year>
<publisher-loc>Abiko, Chiba, Japan</publisher-loc>
<publisher-name>Bird Migration Research Center</publisher-name>
</element-citation>
</ref>
<ref id="B34">
<label>34</label>
<element-citation publication-type="book">
<person-group person-group-type="author">
<name>
<surname>Bianki</surname>
<given-names>VV</given-names>
</name>
<name>
<surname>Dobrynina</surname>
<given-names>IN</given-names>
</name>
</person-group>
<source>
<italic>Migrations of Birds in Eastern Europe and Northern Asia</italic>
</source>
<year>1997</year>
<publisher-loc>Moscow, Russia</publisher-loc>
<publisher-name>Nauka Press</publisher-name>
</element-citation>
</ref>
<ref id="B35">
<label>35</label>
<element-citation publication-type="book">
<collab>Yamashina Institute for Ornithology</collab>
<source>
<italic>Japanese Bird Banding in Recent Years (1961–2004)</italic>
</source>
<year>2004</year>
<publisher-loc>Abiko, Chiba, Japan</publisher-loc>
<publisher-name>Bird Migration Research Center</publisher-name>
</element-citation>
</ref>
<ref id="B36">
<label>36</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Nicolai</surname>
<given-names>CA</given-names>
</name>
<name>
<surname>Flint</surname>
<given-names>PL</given-names>
</name>
<name>
<surname>Wege</surname>
<given-names>ML</given-names>
</name>
</person-group>
<article-title>Annual survival and site fidelity of northern pintails banded on the Yukon-Kuskokwim Delta, Alaska</article-title>
<source>
<italic>Journal of Wildlife Management</italic>
</source>
<year>2005</year>
<volume>69</volume>
<issue>3</issue>
<fpage>1202</fpage>
<lpage>1210</lpage>
<pub-id pub-id-type="other">2-s2.0-27944457222</pub-id>
</element-citation>
</ref>
<ref id="B37">
<label>37</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Miller</surname>
<given-names>MR</given-names>
</name>
<name>
<surname>Takekawa</surname>
<given-names>JY</given-names>
</name>
<name>
<surname>Fleskes</surname>
<given-names>JP</given-names>
</name>
<name>
<surname>Orthmeyer</surname>
<given-names>DL</given-names>
</name>
<name>
<surname>Casazza</surname>
<given-names>ML</given-names>
</name>
<name>
<surname>Perry</surname>
<given-names>WM</given-names>
</name>
</person-group>
<article-title>Spring migration of Northern Pintails from California’s Central Valley wintering area tracked with satellite telemetry: routes, timing, and destinations</article-title>
<source>
<italic>Canadian Journal of Zoology</italic>
</source>
<year>2005</year>
<volume>83</volume>
<issue>10</issue>
<fpage>1314</fpage>
<lpage>1332</lpage>
<pub-id pub-id-type="other">2-s2.0-29244437558</pub-id>
</element-citation>
</ref>
<ref id="B38">
<label>38</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Wahlgren</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Waldenström</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Sahlin</surname>
<given-names>S</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Gene segment reassortment between American and asian lineages of avian influenza virus from waterfowl in the Beringia area</article-title>
<source>
<italic>Vector-Borne and Zoonotic Diseases</italic>
</source>
<year>2008</year>
<volume>8</volume>
<issue>6</issue>
<fpage>783</fpage>
<lpage>790</lpage>
<pub-id pub-id-type="other">2-s2.0-57749114559</pub-id>
<pub-id pub-id-type="pmid">18637721</pub-id>
</element-citation>
</ref>
<ref id="B39">
<label>39</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Campitelli</surname>
<given-names>L</given-names>
</name>
<name>
<surname>Di Martino</surname>
<given-names>A</given-names>
</name>
<name>
<surname>Spagnolo</surname>
<given-names>D</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Molecular analysis of avian H7 influenza viruses circulating in Eurasia in 1999–2005: detection of multiple reassortant virus genotypes</article-title>
<source>
<italic>Journal of General Virology</italic>
</source>
<year>2008</year>
<volume>89</volume>
<issue>1</issue>
<fpage>48</fpage>
<lpage>59</lpage>
<pub-id pub-id-type="other">2-s2.0-38349094190</pub-id>
<pub-id pub-id-type="pmid">18089728</pub-id>
</element-citation>
</ref>
<ref id="B40">
<label>40</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>De Jong</surname>
<given-names>MD</given-names>
</name>
<name>
<surname>Thanh</surname>
<given-names>TT</given-names>
</name>
<name>
<surname>Khanh</surname>
<given-names>TH</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Oseltamivir resistance during treatment of influenza A (H5N1) infection</article-title>
<source>
<italic>New England Journal of Medicine</italic>
</source>
<year>2005</year>
<volume>353</volume>
<issue>25</issue>
<fpage>2667</fpage>
<lpage>2672</lpage>
<pub-id pub-id-type="other">2-s2.0-29144528757</pub-id>
<pub-id pub-id-type="pmid">16371632</pub-id>
</element-citation>
</ref>
<ref id="B41">
<label>41</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Colman</surname>
<given-names>PM</given-names>
</name>
<name>
<surname>Hoyne</surname>
<given-names>PA</given-names>
</name>
<name>
<surname>Lawrence</surname>
<given-names>MC</given-names>
</name>
</person-group>
<article-title>Sequence and structure alignment of paramyxovirus hemagglutinin- neuraminidase with influenza virus neuraminidase</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>1993</year>
<volume>67</volume>
<issue>6</issue>
<fpage>2972</fpage>
<lpage>2980</lpage>
<pub-id pub-id-type="other">2-s2.0-0027243201</pub-id>
<pub-id pub-id-type="pmid">8497041</pub-id>
</element-citation>
</ref>
<ref id="B42">
<label>42</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Ward</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Small</surname>
<given-names>I</given-names>
</name>
<name>
<surname>Smith</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Suter</surname>
<given-names>P</given-names>
</name>
<name>
<surname>Dutkowski</surname>
<given-names>R</given-names>
</name>
</person-group>
<article-title>Oseltamivir (Tamiflu) and its potential for use in the event of an influenza pandemic</article-title>
<source>
<italic>Journal of Antimicrobial Chemotherapy</italic>
</source>
<year>2005</year>
<volume>55</volume>
<issue>1</issue>
<fpage>i5</fpage>
<lpage>i21</lpage>
<pub-id pub-id-type="other">2-s2.0-14744293108</pub-id>
<pub-id pub-id-type="pmid">15709056</pub-id>
</element-citation>
</ref>
<ref id="B43">
<label>43</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Zhu</surname>
<given-names>Q</given-names>
</name>
<name>
<surname>Yang</surname>
<given-names>H</given-names>
</name>
<name>
<surname>Chen</surname>
<given-names>W</given-names>
</name>
<etal></etal>
</person-group>
<article-title>A naturally occurring deletion in its NS gene contributes to the attenuation of an H5N1 swine influenza virus in chickens</article-title>
<source>
<italic>Journal of Virology</italic>
</source>
<year>2008</year>
<volume>82</volume>
<issue>1</issue>
<fpage>220</fpage>
<lpage>228</lpage>
<pub-id pub-id-type="other">2-s2.0-37349127838</pub-id>
<pub-id pub-id-type="pmid">17942562</pub-id>
</element-citation>
</ref>
<ref id="B44">
<label>44</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name>
<surname>Obenauar</surname>
<given-names>JC</given-names>
</name>
<name>
<surname>Denson</surname>
<given-names>J</given-names>
</name>
<name>
<surname>Mehta</surname>
<given-names>PK</given-names>
</name>
<etal></etal>
</person-group>
<article-title>Large-scale sequence analysis of avian influenza isolates</article-title>
<source>
<italic>Science</italic>
</source>
<year>2006</year>
<volume>311</volume>
<issue>5767</issue>
<fpage>1576</fpage>
<lpage>1580</lpage>
<pub-id pub-id-type="other">2-s2.0-33645067624</pub-id>
<pub-id pub-id-type="pmid">16439620</pub-id>
</element-citation>
</ref>
</ref-list>
</back>
<floats-group>
<fig id="fig1" orientation="portrait" position="float">
<label>Figure 1</label>
<caption>
<p>Phylogenetic analysis of avian influenza viruses isolated from Northern pintails in Tohoku district, Japan. Included are different segment of AIVs. Individual tree was generated using neighbor-joining method and 1,000 replications of bootstrap resampling. The number at each branch point indicates percentage probability that the resultant topology is correct. The ORF of each gene segment (a) H1 (1701 bp), (b) N1 (1410 bp), (c) N2 (1410 bp), (d) NS (838 bp), and (e) NP (1497 bp) was employed to generate phylogram. Viruses of the present study were marked by black circle (●) in the tree. Strains with no host were assumed to human isolates.</p>
</caption>
<graphic xlink:href="IRT2012-847505.001"></graphic>
</fig>
<table-wrap id="tab1" orientation="portrait" position="float">
<label>Table 1</label>
<caption>
<p>Avian influenza viruses used in the present study
<sup>a</sup>
.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="1" colspan="1">Virus</th>
<th align="left" rowspan="1" colspan="1">Gene segment sequenced</th>
<th align="center" rowspan="1" colspan="1">HA0 cleavage site
<break></break>
(*cleavage point)
<sup>b</sup>
</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/422/07 H1N1</td>
<td align="left" rowspan="1" colspan="1">HA, NP, NA, and M</td>
<td align="center" rowspan="1" colspan="1">PSVQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/794/08 H1N1</td>
<td align="left" rowspan="1" colspan="1">HA, NP, NA, and M</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Miyagi/1472/08 H1N1</td>
<td align="left" rowspan="1" colspan="1">HA, NP, NA, M, and NS</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Akita/1265/08 H1N2</td>
<td align="left" rowspan="1" colspan="1">HA, NP, NA, M, and NS</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Akita/1353/08 H1N2</td>
<td align="left" rowspan="1" colspan="1">HA, NP, NA, M, and NS</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Akita/1364/08 H1N2</td>
<td align="left" rowspan="1" colspan="1">HA
<sup>c</sup>
, NP, NA, M, and NS</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/1130/08 H1N3</td>
<td align="left" rowspan="1" colspan="1">PB2, PB1
<sup>c</sup>
, PA, HA, NP, NA, M, and NS</td>
<td align="center" rowspan="1" colspan="1">PSIQSR*GLF</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/1192/08 H5N9</td>
<td align="left" rowspan="1" colspan="1">PA, NP, M, and NS</td>
<td align="center" rowspan="1" colspan="1">
<sup>d</sup>
</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Akita/1256/07 H5N2</td>
<td align="left" rowspan="1" colspan="1">NS</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Akita/1355/07 H5N2</td>
<td align="left" rowspan="1" colspan="1">NS</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/385/08 H5N3</td>
<td align="left" rowspan="1" colspan="1">NS</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Aomori/372/08 H7N7</td>
<td align="left" rowspan="1" colspan="1">NS</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/pintail/Miyagi/674/08 H7N7</td>
<td align="left" rowspan="1" colspan="1">NS</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>
<sup>a</sup>
The viruses were isolated from apparently healthy migratory pintails wintering in Japan. Viruses were isolated in embryonated chicken eggs. The entire open reading frame (until otherwise mentioned) of each gene segment was sequenced from PCR product;
<sup>b</sup>
the amino acid sequences were deduced from nucleotide sequences;
<sup>c</sup>
partial sequences—for H1 HA 765 base pair (760-1524) and for PB1 1350 base pair (1-1350);
<sup>d</sup>
not applicable.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tab2" orientation="portrait" position="float">
<label>Table 2</label>
<caption>
<p>Percentage identity (%) of nucleotide sequences of the HA genes of avian influenza viruses: intrahomology and interhomology with interrelated sequences from GenBank.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="1" colspan="1">Virus</th>
<th align="center" rowspan="1" colspan="1">Identity
<sup>a</sup>
(%)</th>
<th align="left" rowspan="1" colspan="1">Highest identity
<sup>b</sup>
(%)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">Subtype H1</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/422/07 H1N1</td>
<td align="center" rowspan="6" colspan="1">96.5–100</td>
<td align="left" rowspan="1" colspan="1">A/duck/Hebei/843/05 H1N2 (97.2)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/794/08 H1N1</td>
<td align="left" rowspan="5" colspan="1">A/wild duck/JX/12416/05 H1N1 (>97.3)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Miyagi/1472/08 H1N1</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1265/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1353/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1130/08 H1N3</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>
<sup>a</sup>
Nucleotide sequence identity among the isolates;
<sup>b</sup>
identity with genes of viruses from GenBank.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tab3" orientation="portrait" position="float">
<label>Table 3</label>
<caption>
<p>Percentage identity (%) of nucleotide sequences of the NA genes of avian influenza viruses: intrahomology and interhomology with interrelated sequences from GenBank.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="1" colspan="1">Virus</th>
<th align="center" rowspan="1" colspan="1">Identity
<sup>a</sup>
(%)</th>
<th align="left" rowspan="1" colspan="1">Highest identity
<sup>b</sup>
(%)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">Subtype N1</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/422/07 H1N1</td>
<td align="center" rowspan="3" colspan="1">96.8–99.8</td>
<td align="left" rowspan="1" colspan="1">A/duck/Tsukuba/67/05 H1N1 (98.8)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/794/08 H1N1</td>
<td align="left" rowspan="2" colspan="1">A/duck/Mongolia/116/02 H1N1 (>98.6)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Miyagi/1472/08 H1N1</td>
</tr>
<tr>
<td align="left" colspan="3" rowspan="1">
<hr></hr>
</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">Subtype N2</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1265/08 H1N2</td>
<td align="center" rowspan="3" colspan="1">99.7–99.9</td>
<td align="left" rowspan="3" colspan="1">A/goose/Gui Yang/3799/05 H5N2 (>98.2)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1353/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1364/08 H1N2</td>
</tr>
<tr>
<td align="left" colspan="3" rowspan="1">
<hr></hr>
</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">Subtype N3</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1130/08 H1N3</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1">A/duck/Niigata/514/06 H5N3 (99.6)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>
<sup>a</sup>
Nucleotide sequence identity within each gene segment of our isolates;
<sup>b</sup>
identity with genes of viruses from GenBank.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tab4" orientation="portrait" position="float">
<label>Table 4</label>
<caption>
<p>Percentage identity (%) of nucleotide sequences of the NS genes of avian influenza viruses: intrahomology and interhomology with interrelated sequences from GenBank.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="1" colspan="1">Virus</th>
<th align="center" rowspan="1" colspan="1">Identity
<sup>a</sup>
(%)</th>
<th align="left" rowspan="1" colspan="1">Highest identity
<sup>b</sup>
(%)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">Segment 8 (NS)</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1256/07 H5N2</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="2" colspan="1">A/mallard/Xuyi/8/04 H11N? (99.4)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1355/07 H5N2</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/372/08 H7N7</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="2" colspan="1">A/duck/Chabarovsk/1610/72 H3N8 (97.4)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Miyagi/674/08 H7N7</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/385/08 H5N3</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1">A/duck/Denmark/65047/04 H5N2 (98.3)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1130/08 H1N3</td>
<td align="center" rowspan="2" colspan="1">50–100</td>
<td align="left" rowspan="2" colspan="1">A/mallard/Italy/4223-2/06H5N2 (>99.3)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1192/08 H5N9</td>
</tr>
<tr>
<td align="left" rowspan="2" colspan="1"> A/pintail/Akita/1265/08 H1N2</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1">A/mallard/Italy/4223-2/06H5N2</td>
</tr>
<tr>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1">A/duck/Primorie/2633/01 H5N3 (both viruses 98.9)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1353/08 H1N2</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="3" colspan="1">A/duck/Primorie/2633/01 H5N3 (>98.9)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1364/08 H1N2</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Miyagi/1472/08 H1N1</td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>
<sup>a</sup>
Nucleotide sequence identity within each gene segment of our isolates;
<sup>b</sup>
identity with genes of viruses from GenBank.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tab5" orientation="portrait" position="float">
<label>Table 5</label>
<caption>
<p>Percentage identity (%) of nucleotide sequences of nucleoprotein (NP) coding genes of avian influenza viruses: intrahomology and interhomology with interrelated sequences from GenBank.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="1" colspan="1">Virus</th>
<th align="center" rowspan="1" colspan="1">Identity
<sup>a</sup>
(%)</th>
<th align="left" rowspan="1" colspan="1">Highest identity
<sup>b</sup>
(%)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">Segment 5 (NP)</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="left" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="2" colspan="1"> A/pintail/Aomori/422/07 H1N1</td>
<td align="center" rowspan="9" colspan="1">90.4–99.9</td>
<td align="left" rowspan="1" colspan="1">A/garganey/SanJiang/160/06 H5N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">A/mallard/Hokkaido/24/09 H5N1 (both viruses 99.5)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/794/08 H1N1</td>
<td align="left" rowspan="5" colspan="1">A/swine/Korea/C12/08 H5N2 (>98.8)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1265/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1353/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Akita/1364/08 H1N2</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Miyagi/1472/08 H1N1</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1130/08 H1N3</td>
<td align="left" rowspan="1" colspan="1">A/garganey/SanJiang/160/06 H5N2 (97.7)</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/pintail/Aomori/1192/08 H5N9</td>
<td align="left" rowspan="1" colspan="1">A/baikal teal/Hongze/14/05 H11N9 A/duck/Hong Kong/MPS180/03 H4N6 (both viruses 97.2)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>
<sup>a</sup>
Nucleotide sequence identity within each gene segment of our isolates;
<sup>b</sup>
identity with genes of viruses from GenBank.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tab6" orientation="portrait" position="float">
<label>Table 6</label>
<caption>
<p>Comparison of avian H1N1 strain with pandemic and seasonal flu strains.</p>
</caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" rowspan="2" colspan="1">Virus</th>
<th align="center" colspan="3" rowspan="1">Aomori/422/07 H1N1 identity (%)</th>
</tr>
<tr>
<th align="center" rowspan="1" colspan="1">Nucleotide</th>
<th align="center" rowspan="1" colspan="1">Amino acid</th>
<th align="center" rowspan="1" colspan="1">Nucleotide</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" rowspan="1" colspan="1">Segment 4 (HA)</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Brevig Mission/1/18 H1N1</td>
<td align="center" rowspan="1" colspan="1">67.8</td>
<td align="center" rowspan="1" colspan="1">92.1</td>
<td align="center" rowspan="1" colspan="1">67.1</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Mexico city/001/09 H1N1</td>
<td align="center" rowspan="1" colspan="1">75.3</td>
<td align="center" rowspan="1" colspan="1">82.5</td>
<td align="center" rowspan="1" colspan="1">74.7</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Japan/AF07/08 H1N1</td>
<td align="center" rowspan="1" colspan="1">76.4</td>
<td align="center" rowspan="1" colspan="1">83.6</td>
<td align="center" rowspan="1" colspan="1">76.4</td>
</tr>
<tr>
<td align="left" colspan="4" rowspan="1">
<hr></hr>
</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1">Segment 6 (NA)</td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="center" rowspan="1" colspan="1"></td>
<td align="center" rowspan="1" colspan="1"></td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Brevig Mission/1/18 H1N1</td>
<td align="center" rowspan="1" colspan="1">84.5</td>
<td align="center" rowspan="1" colspan="1">92.3</td>
<td align="center" rowspan="1" colspan="1">84.5</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Mexico city/001/09 H1N1</td>
<td align="center" rowspan="1" colspan="1">86.5</td>
<td align="center" rowspan="1" colspan="1">90.0</td>
<td align="center" rowspan="1" colspan="1">86.5</td>
</tr>
<tr>
<td align="left" rowspan="1" colspan="1"> A/Japan/AF07/08 H1N1</td>
<td align="center" rowspan="1" colspan="1">79.3</td>
<td align="center" rowspan="1" colspan="1">84.9</td>
<td align="center" rowspan="1" colspan="1">79.5</td>
</tr>
</tbody>
</table>
</table-wrap>
</floats-group>
</pmc>
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