我国与韩国禽流感H9N2病毒血凝素分子特性的区别

The Difference of the Hemagglutinin of H9N2 Chicken Influenza Viruses Isolated in China and Korea

中国与韩国都发生了H9N2亚型禽流感,且都对养禽业造成了严重损失。国际上有不少学者认为韩国的H9N2亚型流感是由中国通过禽肉及其相关产品的输入而引起。本研究针对这一情况对从中国大陆分离的H9N2病毒和自GeneBank读取的韩国H9N2病毒的血凝素核苷酸序列进行了比较分析,结果表明两者属于不同的进化分支。所有中国H9N2病毒的血凝素裂解位点都为-RSSR/G-,而韩国H9N2病毒的血凝素裂解位点为-ASVR/G-、-ASYR/G-或-ASGR/G-。韩国H9N2病毒血凝素的受体结合位点的氨基酸在第183、190和226位点分别H、E和Q;而中国毒株的变异较大,在第183位点全部为N,190位点为A、T或V,第226位点为L或Q。因此,中韩两国的H9N2病毒血凝素分子特性显著不同。

The phylogenetic relationships among the hemagglutinin(HA)genes of China isolates and those of Korea H9N2 viruses from the database were analyzed.The results showed that China H9N2 isolates and Korea isolates fell into a different lineage.Amino acid sequence at the cleavage site of the HA of China H9N2 viruses possessed a -RSSR/G-motif.However,Korea isolates possessed -ASVR/G,-ASYR/G- or ASGR/G-.Amino acids at positions 183,190,and 226 in the receptor-binding sites of Korea isolates had H,E and Q respectively.These contrast with those of China isolates that had N-183,A,T,or V at position at 190,L or Q at position 226.The present results indicate that the molecular characters of hemagglutinin of Korea H9N2 viruses are different from those of China isolates.