1株鸭源Ⅰ类新城疫病毒分离株F和HN基因的分子特性分析

采用RT-PCR技术对Ⅰ类新城疫病毒(NDV)09-014分离株完整的融合蛋白(F)基因和血凝素-神经氨酸酶(HN)基因进行了扩增和遗传进化分析。F基因的序列测定结果表明:该分离株F基因全长为1 792 bp,可编码553个氨基酸,裂解位点的氨基酸组成为112E-R-Q-E-R-L117,具有典型的新城疫弱毒株特征。同源性分析表明本分离株的F基因与Ⅰ类新城疫病毒代表毒株之间核苷酸的同源性为93%～95.2%,而与Ⅱ类新城疫病毒代表毒株的同源性较低,介于70.6%～72.4%。HN基因的序列测定结果表明:HN基因全长2 001 bp,可编码616个氨基酸,同源性分析表明本分离株的HN基因与Ⅰ类新城疫病毒代表毒株之间核苷酸的同源性在92.7%～94.7%之间,而与Ⅱ类新城疫病毒同源性较低,为70.7%～71.5%。根据完整的F基因和HN基因构建的遗传进化树均表明:本分离株在分类地位上属于Ⅰ类新城疫病毒基因3型,因此Ⅰ类新城疫病毒的F基因和HN基因具有相似的进化速率。

Molecular characterization of F and HN genes of class I Newcastle disease virus in China

The F and HN genes of Newcastle disease virus(NDV) strain NDV09-014,isolated from domestic duck in China,were amplified by RT-PCR and sequenced.The complete F gene was composed of 1 792 nucleotides,encoding 553 amino acids.The motif of the cleavage site of the fusion protein was 112E-R-Q-E-R-L117,which is typical of lentogenic NDV strains.Homology analysis of F gene revealed that sequence similarities among classⅠ NDV isolates varied from 93% and 95.2%,and showed relative lower identities between this isolate and classⅡ NDV strains,70.6% to 72.4%.The full length of HN gene comprised of 2001 nucleotides,encoding 616 amino acids.Homology analysis of HN gene revealed that sequence similarities among classⅠ NDV isolates varied from 92.7% to 94.7%,and 70.7% to 71.5% of identities between this isolate and classⅡ NDV strains.Phylogenetic analysis based on the complete F and HN gene sequences showed that the NDV09-014 isolate was grouped into genotype 3 in classⅠ.It suggested that the evolutionary rates in F and HN genes of classⅠ were similar.