【摘要】 运用RT-PCR方法扩增A/Chicken/Zhejiang/HJ/2007(H9N2)毒株8基因片段,序列比较及遗传进化分析结果表明,所克隆的8个基因片段均有HJ毒株完整的开放阅读框,其血凝素基因(HA)(FJ581431)蛋白裂解位点的氨基酸组成为-PSKSSR*G-,为不连续的碱性氨基酸,符合低致病性AIVHA基因裂解位点的序列特征;与QA/HK/G1/97的进化关系较近。其神经氨酸酶基因(NA)(FJ581434)在遗传进化上属于常见的CK/BJ/1/94群系。核蛋白基因(NP)(FJ581428)整合有同地分离的H5N1亚型流感病毒NP基因片段,进化关系较近。基质蛋白基因(M)(FJ581432)与1999年香港感染儿童的两株流感病毒在进化关系属于同一分支。非结构蛋白基因(NS)(FJ581433)和1998年首次报道的猪源H9N2亚型流感病毒处在同一进化分支。聚合酶蛋白基因PB1(PB1)(FJ581435)从33～47位存在15个连续碱基缺失,是首次报道该基因ORF内存在缺失,且和聚合酶蛋白基因PA(PA)(FJ581430)在遗传进化上类似,均与近年来分离的H5N1亚型流感病毒处在同一分支;聚合酶蛋白基因PB2(PB2)(FJ581429)与常见的流感病毒毒株的遗传进化关系较远。因此,A/Chicken/Zhejiang/HJ/2007(H9N2)是由不同流感病毒基因亚系间发生自然重排的产物。更多还原

【Abstract】 The eight full-length genes of H9N2 Subtype avian influenza virus A/Chicken/Zhejiang/HJ/2007(H9N2) were amplified by reverse transcription-polymerase chain reaction(RT-PCR), and cloned to pMD18-T vector and sequenced.The sequenced results revealed that the hemagglutinin(HA) gene’s(FJ581431) deduced amino acid sequence at the cleavage site of the HA protein was-PSKSSRG-, which was match to the characteristic of low pathogentic avian influenza(LPAI), and also belongs to the A/Quail/Hong Kong/G1/97(H9N2) sublineage, not the same as most of the H9N2 Subtype avian influenza virus belong to the A/Chicken/Beijing/1/94(H9N2) sublineage.The neuraminidase(NA) gene(FJ581434) had deletions at 63, 64 and 65 amino acids derived from the A/Chicken/Beijing/1/94(H9N2) sublineage.The nucleoprotein(NP)(FJ581428) was similar with some H5N1 Subtype influenza virus which were also isolated in Zhejiang Province;they all had near phylogenetic relationship.The matrix protein(M)(FJ581432) was at one sublineage with A/Hong Kong/1073/99(H9N2) and A/Hong Kong/1074/99(H9N2), and the two viruses infected two children in Hong Kong at 1999.The nonstructural proteins(NS)(FJ581433) had near relationship with H9N2 Subtype swine influenza virus isolated during the past few years in China, which at one sublineage with A/Swine/Hong Kong/9/98(H9N2).However, the polymerase proteins PB1 gene(FJ581435) had 15 nucleotides(caatccgactttact)deletions from 33 to 47, which first reported that there were 5 amino acids deletion in its ORF.The polymerase PA gene(FJ581430) and the polymerase PB1 gene had familiar phylogenetic, which were near to the H5N1 subtype influenza virus.However, the polymerase PB2 gene(FJ581429) had not shown any immediate ancestor with the different avian influenza viruses used in the paper.Therefore, A/Chicken/Zhejiang/HJ/2007(H9N2) is the product of natural reassortment from different influenza virus sublineages.更多还原