【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。更多还原

【Abstract】 【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.更多还原