禽流感病毒分离株A/Goose/Guangdong/3/96(H5N1)HA基因序列分析

采用RT_PCR技术,以A/Goose/Guangdong/3/96(H5N1)RNA为模板,扩增了1.73kb 的HA 全基因cDNA。将HAcDNA克隆后进行了序列测定,测序结果表明所扩增的1728 个核苷酸片段包含了完整的HA基因的开放阅读框架和上下游引物序列、蛋白质合成的起始密码子和终止密码子。核苷酸序列比较分析结果表明:A/Goose/Guangdong/3/96(H5N1) 与A/Goose/Guangdong/1/96(H5N1)有11 个核苷酸差异,同源率99.4% ;与A/HongKong/156/97(H5N1) 有25 个核苷酸差异,同源率98.6 % ;与A/Chicken/HongKong/258/97 (H5N1) 有30 个核苷酸差异,同源率98.3% ;它们的氨基酸序列同源率依次分别为99 .2 % 、98.6% 和98.1% 。受体结合位点的氨基酸序列完全一致;HA裂解位点氨基酸序列也完全一致,各有5 个碱性氨基酸插入。这说明上述4 个流感病毒分离株可能来自同一个祖先,具有相同的毒力和相似的生物学特性。

Analysis of Hemagglutinin Gene of Avian Influenza Virus Isolate A/Goose/Guangdong/3/96(H5N1)

In this study, full-length cDNA of HA gene of A/G oo se/Guangdong/3/96(H5N1)(GD/3) was amplified using RT-PCR method. The cDNA was cl oned into Sma I site of pUC18 plasmid and then sequenced. The result of sequenci n g shows that the cDNA contains whole open reading frame of HA gene, initiation c odon and termination codon. The results of comparative sequence analysis indicat ed that the sequence of the cDNA had 11 nucleotide differences and 99.4% of homo logy with A/Goose/Guangdong/1/96(H5N1)(GD/1),25 nucleotide differences and 98.6% of homology with A/HongKong/156/97(H5N1)(HK/156),and 30 nucleotide differences and 98.3% of homology with A/Chicken/HongKong/258/97(H5N1)(HK/258). Furthermore, the HA of GD/3 had the homology of 99.2% with GD/1,98.6% with HK/156, and 98.1% with HK/258 at amino acid level. They shared the same basic amino acid insert a t the cleavage site, which indicates that all 4 influenza virus isolates are pro bably evolved from same ancestor and have similar virulence and biological prop erties.