【摘要】 对分离自北方地区发病鸡群中的四株H9N2亚型禽流感病毒(AIV)进行了血凝素(HA)基因的全长扩增和序列测定。将其核苷酸序列及推定的氨基酸序列与GenBank中已有的参考序列进行比较并绘制了系统进化树。结果表明基于HA基因多个不同的核苷酸区段所做的系统发育分析结果基本一致。尽管分离时间不同,但这四株AIV的HA基因同源性很高,均属于A/DK/HK/Y280/97-like病毒。四株病毒在HA裂解位点、受体结合位点以及推测的糖基化位点的氨基酸序列均与上述亚系相似,但是其中的两株病毒由于一个核苷酸的变异,缺失了HA上298~300位的一个潜在的糖基化位点。更多还原

【Abstract】 Four H9N2 avian influenza viruses were isolated from sick chickens in Northern China.The sequences of the hemagglutinin genes of these isolates were determined by RT-PCR and sequencing.The homology of these nucleotide sequences and putative amino acid sequences were compared with H9N2 in GenBank.Phylogenetic tree based on different regions in nucleotide sequences of HA gene cDNA was also analyzed.Although the isolating time of four viruses was different,they were highly homologous and all belong to the same sublineage of H9N2 Eurasian lineage,A/CK/HK/G9/97-like group. Their amino acid sequences that involved in HA cleavage sites,receptor binding sites and potential glycosylation sites were also similar to the above sublineage.However,two of the four isolated viruses,CK SD B1 98 and CK BJ L1 05 had a deletion of potential glycosylation site because of a single nucleotide variation on HA gene.更多还原