7株广西鸭源NDV分离株全基因序列测定及遗传进化分析

Sequencing and phylogenetic analysis of the genomes of seven Newcastle disease viruses isolated from duck of Guangxi

根据GenBank公布的B1毒株(AF375823.1)全基因组序列,使用软件Primer Premier 5.0进行引物设计及引用已发表引物,经过筛选,最终用于扩增鸭源新城疫病毒(NDV)全基因组序列的引物为15对,运用RT-PCR方法获取了7株鸭源NDV毒株结果表明7株鸭源NDV毒株GX16/2008、GX17/2009、GX18/2009、GX19/2009、GX20/2010、GX21/2010和GX22/2010的全基因组序列,并对其进行了比较分析。此7株病毒的全基因组序列均由15 186个碱基组成,GenBank登录号为JX193077-JX193083。F蛋白裂解位点的氨基酸序列表明所有的分离株都是无致病性的序列。7分离株中5株氨基酸顺序为112 G-K-Q-G-R-L117,2株为112 G-R-Q-G-R-L117,绘制的进化树分析表明其中5株属于NDVs基因Ⅰ型,2株属于基因Ⅱ型。它们在全基因组核苷酸和氨基酸水平上,发现与HM125898WDK/JX株相似性较接近,而与F48E8、Mukteswar等毒株的同源性较低。

Fifteen pairs of specific primers were designed and synthesized based on the entire genomic sequence data of Newcastle disease virus（NDV）present in GenBank.Complete nucleotide sequences of GX16/2008,GX17/2009,GX18/2009,GX19/2009,GX20/2010,GX21/2010 and GX22/2010were acquired by reverse transcription-polymerase reaction.The entire genomic sequences of seven NDV strains consisted of 15/86 nt,their GenBank accession numbers were from JX193077 to JX193083.Deduced amino acid sequence of the cleavage site of fusion（F）protein revealed that all isolates had avirulent motifs.Of the 7 isolates,5 exhibited sequence motif of 112 GK-Q-G-R-L117 at the cleavage site,2 exhibited 112 G-R-Q-G-R-L117.Phylogenetic analysis based on comparison with different NDV sraines revealed that 5 isolates were phylogenetically close to genotypeⅠ NDVs while 2 were close to genotypeⅡ.The results of identity analysis of nucleotide and amido acid sequences showed that the identities of these strains between HM125898 WDK/ JX,were higher than of F48E8,Mukteswar strains.