5株野生鸟类Ⅸ型NDV分离株HN基因的分子特征分析

Molecular characteristic analysis of five Newcastle disease virus isolates' HN gene originated from wild birds

探讨新城疫病毒（Newcastle disease virus,NDV）血凝素-神经氨酸酶基因（HN基因）的分子进化特点,为科学防控新城疫（Newcastle disease,ND）提供依据。【方法】对2008年从陕西省周至县楼观台及其周边地区分离的5个野生鸟类NDV毒株的HN基因进行扩增与测序,与8个国内外不同时期已发表的NDV毒株HN基因进行核苷酸和推导的氨基酸序列的遗传变异分析及分子特性研究。【结果】所有分离株与国内参考强毒株F48E9和国外参考强毒株Herts-33在HN基因C末端终止密码子的位置相同,符合强毒株的特征。从核苷酸和氨基酸同源性来看,分离株与F48E9的核苷酸和氨基酸同源性分别为99.6%~99.8%和99.1%~99.7%,与LaSota、B1和clone-30的同源性分别为90.2%~91.8%和87.9%~88.5%,与ZJ1的同源性为84.8%~85.0%和89.3%~89.7%;从系谱进化分析来看,这5个毒株与F48E9关系较近,同属一支,与LaSota、ZJ1、Herts-33等疫苗株和参考毒株关系较远。【结论】该生态区NDV野生鸟类分离株与目前流行的基因Ⅶ型毒株和传统疫苗毒株的关系较远,且具有强毒株的分子特征,因此必须加强该地区野生鸟类新城疫病毒的监测。

[Objective] To scientifically control and prevent Newcastle disease （ND）, this study researched the molecular evolution characteristics of HN gene of Newcastle disease viruses（NDV）. [Method] The nucleotide sequences and deduced amino acid sequences were analyzed for HN gene of five field isolates of NDV. The HN gene sequences of fifteen NDV reference strains in GenBank were also used in this study. [Result] The nucleotide and amino acid homology of NDV isolates and F48E9 were 99.6%- 99.8% and 99.1%--99.7% respectively,but 90.2%--91.8% and 87.9%--88.5% compared with LaSota, clone-30 and B1 ,and 84. 8%--85. 0% and 89.3%--89.7% to ZJ1 strains. The phylogenetic tree based on the nucleotide sequences of HN gene revealed that the 5 isolates of NDV and F48E9 were of the same subgenotype. [Conclusion] The wild birds in the area of Louguantai carry Virulent NDVs, HN gene of the five NDV isolates had a distant genetic relationship with the vaccine strain e. g. LaSota, clone-30,and epidemical strain in poultry. Thus,epidemiological studies should be carried out constantly to monitor wild bird populations in general.