中国动物传染病学报2011，Vol.19Issue(6)：7-14,8.
异源5′非翻译区在猪繁殖与呼吸综合征病毒感染性拯救过程中的功能解析
THE RECOVERY OF CHIMERIC TYPE II PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS WITH REPLACEMENT OF TYPE 1 5＇ UNTRANSLATED REGION
摘要
Abstract
The 5＇ untranslated region （UTR） of the genomic RNA is believed to be vital for the replication and transcription of Porcine reproductive and respiratory syndrome virus （PRRSV）, but its functional mechanism remains unclear. In the present study, a chimeric clone pAPLV5 was generated by substituting type I 5＇ UTR into the backbone of infectious full-length cDNA clone pAPRRS of type II attenuated strain. After two passages post transfection in MARC-145 cells, the chimeric virus vAPLV5 was rescued. Sequence analysis of full-length genome of the chimeric virus vAPLV5 identified several nucleotide mutations, which mainly occurred in Nsp2 and Nsp9. Subsequently, four mutations that were generated in Nsp9 （RNA dependent RNA polymerase, RdRp） were introduced into the chimeric clone pAPLV5 to create four different mutants. As a result, transfected MARC-145 cells developed CPE without any passage. Viral titers of these four mutants were higher than original chimeric virus pAPLV5. Semi- quantitative RT-PCR was conducted for negative-strand genomic RNAs and sg mRNAs analysis. The results showed that the RNA synthetic level of the four mutant viruses were higher than vAPLV5. In conclusion, PRRSV 5＇ UTR was closely associated with theregulatory function of RdRp, and heterologous 5＇ UTR might play a role in virus rescuing processes through alteration in RdRp.关键词
非翻译区/RNA依赖的RNA聚合酶/嵌合病毒/转染Key words
Untranslated region （UTR）/RNA dependent RNA polymerase（RdRp）/chimeric virus/transfection分类
农业科技引用本文复制引用
高飞,陆嘉琦,姚火春,杨倩,袁世山,童光志..异源5′非翻译区在猪繁殖与呼吸综合征病毒感染性拯救过程中的功能解析[J].中国动物传染病学报,2011,19(6):7-14,8.基金项目
国家自然科学基金面上项目（30972204) （）
欧盟“第七框架”项目（245141) （）
