4个H9N2亚型禽流感病毒毒株HA基因序列比较与分析

Sequence Comparison and Analysis of HA Gene of Four H9N2 Avian Influenza Virus Isolates

[目的]测定H9N2 AIV4个毒株血凝素基因序列,并进行比较分析,从分子生物学角度了解各毒株间的差异和变异规律,进而了解该亚型禽流感的分布及流行规律。[方法]参照H9N2亚型禽流感HA基因序列设计1对引物,对禽流感A/Chicken/Hebei/WD/98(H9N2)、A/Chiken/Hebei/ZD/04(H9N2)、A/Chicken/Beijing/MY/06(H9N2)和A/Chicken/Beijing/PG/08(H9N2)4个毒株HA基因进行扩增、克隆和测序,并将这4个毒株的HA基因序列分别与GenBank登录的10个H9N2亚型禽流感毒株进行比较分析。[结果]获得了4个毒株HA基因(ORF)全长1 683 bp,编码561个氨基酸;4个毒株之间的核苷酸和氨基酸同源性分别为92.5%～95.6%和95.2%～96.8%;WD株、MY株、PG株和ZD株与其他10个毒株的核苷酸和氨基酸序列同源性分别为82.6%～95.1%、83.0%～99.0%、82.7%～95.5%、81.30%～95.7%、86.6%～96.3%、86.6%～97.9%、87.0%～97.1%、86.9%～97.3。[结论]HA基因在不同毒株间具有很高的同源性。

[ Objective ] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the angle of molecular biology and to know the distribution and epidemic law of H9N2 AIV. [ Method] One pair of primers was designed referring to HA gene sequences of H9N2 AIV. The HA genes of A/Chicken/Hebei/WD/98 （ H9N2 ; WD98 for short ）, A/Chicken/Hebei/ZD/04 （ H9N2 ; ZD04 for short ） , A/Chicken/Beijing/MY/06 （H9N2; MY06 for short）, and A/Chicketr/Beijing/PG/08 （H9N2; PGO8 for short） were amplified, cloned and sequenced. Then the HA gene sequences of these strains were compared with that of 10 H9N2 AIV stains in GenBank. [ Result ] The ORF of HA genes of the four strains was 1683 bp in size, encoding 516 amino acids. The HA gene sequences of the four strains, WD98, MY06, PG08, and ZDO4, were 82.6% - 95.1%, 83.0% - 99.0%, 82.7% - 95.5% , and 81.3% 95.7% homologous to that of the 10 H9N2 AIV stains, respectively. And the honmlogy of amino acid was respectively 86.6% - 96.3%, 86.6% - 97.9%, 87.0% - 97. 1%, and 86.9% 97.3%. [ Conclusion] The HA gene HAs greatly high homology among different strains.