小反刍兽疫病毒FY株全基因组序列的测定及其分子特征的研究

Genome sequencing and analysis of peste des petits ruminants virus FY strain

根据小反刍兽疫病毒(PPRV)参考序列设计了11对特异性引物,然后用RT-PCR方法分段扩增出PPRV富阳分离株(PPRV-FY)的全基因组序列,用DNAstar软件和Mega软件对PPRV-FY株及参考毒株的基因序列进行了比对和分析,并根据N基因核苷酸序列绘制了系统进化树。结果,PPRV-FY株全长15 948 bp,编码6种结构蛋白(N、P、L、M、F和H),2种非结构蛋白(C和V),PPRV各毒株转录起始序列和转录终止序列都高度保守。同源性分析结果表明,PPRV-FY株与PPRV-Coted′Ⅰvoire89同源性最低,为89.0%,与PPRV/Tibet/30/2007株和PPRV/Tibet/2007株的同源性最高,为97.3%,其基因间隔区N-P长度一致,相似度最高,而M-F相似度最低。通过比较PPRV-FY株与参考毒株基因组末端调控序列,可以看出整个麻疹病毒属GP区和AGP区保守性较高,且存在不同程度的互补。氨基酸序列分析结果表明,PPRV-FY株在保守区域出现21处氨基酸突变,这些突变对其所编码蛋白的结构和功能有何影响尚需要进一步研究。此外,本文还基于N基因序列,对PPRV-FY株及参考毒株进行了系统进化分析。结果表明,PPRV-FY株与其它亚洲源PPRV野毒株共同形成一个拓扑群,属于第IV谱系。

The peste des petits ruminants virus isolated from FuYang（PPRV-FY strain） was subcloned and sequenced. Firstly,ll pairs of specific primers were designed according to the PPRVreference se- quences. Secondly the complete genome of PPRV-FY strain was amplified by RT-PCR method. Finally,the DNAstar and Mega softwares were used to compare and analyze the gene sequences of PPRV-FY strain with reference strains, and to construct the phylogenetic trees, In this paper,the results showed that the total length of PPRV-FY was 15948nt,encoding 6 structural proteins（N, P, L, M, F and H） and two nonstru- ctural proteins（C and V）.The transcription initiation and termination sequences of all the PPRV stra- ins were highly conservative. In the aspect of gene sequence homology,the homology with the PPRV- Coted＇Ivoire89 strain was the lowest, which was 89~,and the homology with the PPRV-ribet/30/2007 strain and the PPRV-Tibet/2007 strain was the highest, which was97.3%.In the aspect of interval se- quence,the N-P was identical in length and had the highest similarity,while the M-F region was the low- est. Then by comparing the PPRV-FY strain with the reference strains,the GP region and AGP region were conservative, and there were different degrees of complementarity. The amino acid sequence analysis showed that there were 21amino acid mutations in the conserved region of PPRV-FY strain, but the effect of these mutations on the structure and function of the protein encoded by these mutants need to be studied further. In addition,phylogenetic analysis of the PPRV-FY strain was carried out based on the N gene sequence with the reference strains. The results showed that PPRV-FY strains and other PPRV wild strains isolated from Asia together come from a topological group,belonging to the IV spectrum.