猪瘟病毒3′非编码区的多态性及其二级结构分析  

Heterogeneity and Secondary Structure Analysis of 3'Untranslated Region in Attenuated Classical Swine Fever Viruses

作　　者：范运峰[1,2] 赵启祖[1] 赵耘[1] 邹兴启[1] 张仲秋[1,2] 王琴[1] 宁宜宝[1] 

机构地区：[1]中国兽医药品监察所,北京100081 [2]中国动物疫病预防控制中心,北京100125

出　　处：《中国农业科学》2010年第4期828-834,共7页Scientia Agricultura Sinica

基　　金：国家自然科学基金资助项目(30571377);国家"863"计划项目(2006AA10A204)

摘　　要：【目的】分析CSFV3′-UTR一级序列和二级结构,为研究其对病毒复制、增殖和毒力的关系奠定良好的基础。【方法】利用RT-PCR技术扩增CSFV Thiverval株、HCLV株和Shimen株的3′-UTR并测序,使用DNAstar、Sequencher和RNAstructure软件进行CSFV3′-UTR基因组序列的比对分析和二级结构模拟。【结果】Thiverval株3′-UTR最长可达259个碱基,与母源株Alfort相比,含有32nt的插入,最短只有233个碱基,含有6nt的插入。HCLV株最长有244个碱基,含有17nt的插入;最短有233个碱基,含有8nt的插入。同时,疫苗株的插入片段导致3′-UTR空间构型和自由能发生改变,自由能随着插入片段的增加而升高。【结论】(1)CSFV3′-UTR存在两个高度变异的区域。(2)CSFV疫苗株Thiverval株和HCLV株3′-UTR同一样品不同克隆株中插入片段呈现明显的不均一。(3)疫苗株的插入片段影响3′-UTR二级结构的稳定性,可能是导致疫苗株毒力减弱的原因之一。[ Objective] The 3＇-UTR of CSFV was sequenced and analyzed, for the understanding of the influence of 3＇-UTR on replication, multiplication, and virulence of virus. [Method] The 3＇-UTR of CSFV Thiverval, HCLV and Shimen strains were amplified and sequenced using RT-PCR method. The alignment was carried out using DNAstar and Sequencher software. The RNA secondary structures of different 3＇-UTR were predicted using RNAstructure software. [ Result] The longest 3＇-UTR of Thiverval strain was 259 base pairs （bp） with a 32 nt insertion. The shortest 3＇-UTR had only 233 bp with a 6 nt insertion. The longest 3＇-UTR of HCLV strain was 244 bp with a 17 nt insertion and the shortest 3＇-UTR was 235 bp with a 8 nt insertion. At the same time, to maintain the similar 3＇-UTR structure, the free energy of vaccine strain is higher than that of virulent strain, and the free energy in 3＇-UTR of vaccine strain is rising with length of insert. [Conclusion] The 3＇-UTR of CSFV vaccine strains have two variable regions. The insertion of attenuated Thiverval and HCLV strains 3＇-UTR represent distinct heterogeneity in different clones of the same sample. The insertion of vaccine strains 3＇-UTR could affect the stability of the secondary structure, which might be a reason for the attenuated virulence.

关 键 词：猪瘟病毒 3'-UTR 不均一性 二级结构分析 

分 类 号：S852.65[农业科学—基础兽医学]