鹅源禽副粘病毒NA-1株HN蛋白基因的遗传变异研究

鹅副粘病毒分离株NA-1株经11日龄鸡胚增殖后纯化。提取病毒的基因组RNA，采用RT-PCR扩增出与预期设计的1．7kb大小相符合的特异条带。将扩增产物提纯后克隆入pMD18-T载体，经纯化、筛选及酶切鉴定后，初步获得了含鹅副粘病毒HN基因的阳性克隆，并对阳性克隆进行了测序。测序后拼接得出HN基因的全序列长度为1740bp，该基因的ORF总长为1716bp，编码571个氨基酸。与GenBank下载的15株参考毒株比较HN基因编码区全核苷酸序列，发现所测NA-1株与国内标准强毒株F48E9核苷酸的同源性为84．5％，氨基酸的同源性为89．5％；与传统的疫苗株La Sota核苷酸的同源性为82．2％，氨基酸的同源性为88．5％；与鹅源禽副粘病毒SF02株核苷酸的同源性为97．1％，氨基酸的同源性为97．4％；与鹅源禽副粘病毒YG97株核苷酸的同源性为97．3％，氨基酸的同源性97．4％。说明NA-1株和SF02株、YG97株亲缘关系较近，它们三者可能有着共同的来源。根据基因树分析，NA-1株应属于基因VII型新城疫病毒。由此更进一步证实新城疫可以感染水禽，且对鹅具有高度的致死性。

HN gene's genetic variation of avain paramyxovirus-I strain NA-1 isolated from goose

Avian paramyxovirus strain NA-1 isolated from goose was propagated in 11-day-old chicken embryos.The genomic RNA of NA-1 were extracted.The HN gene of the virus has been successfully amplified by RT-PCR,and further cloned into pMD 18-T vector,and a positive recombinant plasmid was obtained by restriction enzyme analysis.The complete sequence of HN gene was obtained finally and the nucleotide sequence of the HN gene was 1 740 bp.The sequence analysis demonstrated that 15 reference strains loaded down from GenBank,the result of ORF sequence analysis indicated that NA-1 strain exhibited 97.3 % homology of the nucleotide and 97.4 % homology of the amino acid with reference strain YG97,97.1 % homology of the nucleotide and 97.4 % homology of the amino acid with reference strain SF02,which indicated they probably had a common origin.84.5 % homology of the nucleotide with strain F48E9 and 82.2 % homology of the nucleotide with strain LaSota.The results indicated the mutation of the HN gene between the goose's,paramyxovirus and NDV varied to a great extent.A phylogenetic tree based on the published sequences of NDV reference strains was constructed and showed the isolated NA-1 belonged to the genotype VII NDV,a novel genotype NDV.It is proved that NDV can infect goose and have a higher mortality.