禽流感病毒N8亚型神经氨酸酶基因的克隆和全序列分析

Cloning and sequencing of full-length neuraminidase gene of avian influenza virus N8 subtype

用SPF鸡胚增殖禽流感病毒A/Duck/Australia/341/83(H15N8),通过RT-PCR获得了NA基因全长,连接并转化,增菌培养后,提取阳性质粒进行序列测定,获得了禽流感病毒N8亚型的NA基因序列,分析了NA8基因与其他流感病毒神经氨酸酶基因的相互关系。结果显示,所获得的NA基因片段全长1459bp,最大开放阅读框编码457个氨基酸残基,经Blast分析,该基因与GenBank中其他13株N8亚型毒株的NA基因核苷酸序列同源性为91.6%～73.3%。与其他8个N1～N9亚型NA基因进行遗传演化分析,N8亚型与N5亚型NA基因的亲缘关系最近,与N3亚型NA基因的亲缘关系最远。结果表明,禽流感病毒N8亚型NA基因序列的测定对N8亚型流感病毒的诊断和预防具有重要意义。

The avian influenza virus（AIV） A/Duck/Australia/341/83（H15N8） was propagated in 9-day-old embryonated SPF chicken eggs. The complete NA gene of influenza virus A/Duck/Australia/341/ 83（H15N8） was amplified by RT-PCR,and then cloned and sequenced. The N8 NA gene was 1 459 bp,en-coding 457 amino acids. The amino acid sequence from N8 NA gene possessed 7 potential glycosylation sites and 17 cysteines in the NA protein. The N8 NA gene sequence shared from 91.6% to 73.3% homology rates with that of 13 AIV strains available in GenBank. The phylogenetic tree based on NA gene of N1 to N9 subtypes showed that the NA gene of N8 subtype was closed with that of N5 subtype and was farthest with that of N3 subtype. The results showed that sequencing of N8 NA gene of AIV was very important for the diagnosis and control of the virus.