鸭Ⅰ型禽副粘病毒YH99V株HN基因的克隆和序列分析

在浙江地区进行鸭病病因的调查过程中，从患病鸭群中分离到一株引起鸭产蛋锐减而不死亡的病毒，经鉴定该病毒属于禽副粘病毒Ⅰ型，命名为YH99V株。以YH99V株的基因组RNA为模板，通过RT—PCR一步法扩增出其HN基因的cDNA片段，然后将其克隆至pMD18-T载体中，对其进行序列测定。测序后拼接出HN基因的序列长度为1785bp，该基因的ORF总长为1734bp，编码577个氨基酸。将YH99V株HN基因序列和推导的氨基酸序列与新城疫毒株的HN基因相应序列比较后发现，它们的核苷酸序列同源性分别在82．1％～99．7％，氨基酸序列同源性为87．2％～99．5％。在同源性比较的基础上，进一步绘制了Ⅰ型禽副粘病毒株HN基因的系统发育树。这对于Ⅰ型禽副粘病毒毒力基因的功能分析和该病的分子流行病调查有着重要的意义。

Cloning and sequencing of HN gene of avian paramyxovirus type 1 strain YH99V isolated from duck

The natural outbreaks of the enzootic disease in the duck have been recorded in Zhejiang province, and one virus, which caused duck egg laying drop was isolated from duck. The virus was identified as avian paramyxovirus - 1 and designated as strain YH99V. Using the viral genome RNA as template, cDNA fragments of HN gene of strain YH99V was amplified by one-step RT-PCR which was cloned into pMD18-T vector and sequenced.The complete sequence of HN gene was obtained finally and the nucleotide sequence of HN gene was 1 785 bp, a single open reading frame encodes a polypeptide of 577 amino acids. The nucleotide sequence of HN gene and the deduced amino acid sequence of HN protein of strain YH99V were compared with the published sequences of HN gene of NDV strains, and the homology was between 82.1%-99.7 % in nucleotide sequence, 87.2 %-99.5 % in deduced amino acid sequence. Based on alignments of nucleotide sequences of F gene the phylogenetic tree was constructed. The data are important for working over the function of F gene encoding protein and the investigation of molecular epidemiology of avian paramyxovirus published sequences of NDV strains.