福建省H9N2亚型禽流感病毒HA和NA基因的进化分析

摘要

Haemagglutinin（HA） and neuraminidase（NA） genes of two H9N2 subtype viruses（FZ-04 and FZ-11） isolated from different broiler flocks in Fujian in 2011 were amplified and sequenced in order to determine their genetic relationship with other Avian influenza virus strains that were either isolated from the same area during 2000-2011 or deposited in GenBank.The nucleotide sequences of haemagglutinin genes of both strains had the highest identity with CK/FJ/G9/09,indicating these strains belonged to the same major genetic CK/BJ/1/94 like sublineage.The FZ-04 and FZ-11 strains had-PSRSSR/GL-sequence at HA proteolytic cleavage sites,a characteristic of low pathogenic Avian influenza virus（LPAIV）.The neuraminidase gene of FZ-04 and FZ-11 strains encoded 469 amino acid sequences and had no nucleotides deletion.Phylogenetic analysis of NA genes showed that both strains had the highest homology with CK/FJ/10954/05 and belonged to genetic CK/HK/G9/97 like sublineage.On the basis of phylogenetic analysis of HA and NA genes,we concluded that H9N2 subtype Influenza viruses circulating in chicken flocks in Fujian during 2000-2011 might have a stable evolution and common origin.%为进一步了解福建省H9N2亚型禽流感病毒的基因遗传进化关系,本研究将福建省2011年分离的毒株FZ-04、FZ-11与GenBank上登录的2000～2011年福建省分离的H9N2毒株及国内外典型代表株进行HA、NA基因的序列比对和遗传进化分析。结果表明,分离株FZ-04和FZ-11的HA基因与CK/FJ/G9/09株核苷酸同源性最高,属于国内常见的CK/BJ/1/94亚系。HA裂解位点处的氨基酸序列为-PSRSSR/GL-,符合低致病性禽流感病毒的分子特征。NA基因在遗传进化关系上呈现独立的分支,与CK/FJ/10954/05毒株核苷酸序列同源性最高,属于CK/HK/G9/97亚系,且NA基因推导的469个氨基酸序列中没有缺失。同时,从HA和NA基因的遗传进化树上可知,2000～2011年福建省H9N2禽流感病毒进化相对比较稳定,可能有一个共同的起源。