猪繁殖与呼吸综合征病毒GS株非编码区分子克隆及其一二级结构的分析

参照GenBank中PRRSV VR-2332株全序列对非编码区(non-coding region,NCR)设计特异性引物,经过基因的扩增、连接、转化、筛选阳性克隆以及核苷酸测序.结果表明PRRSV GS株5′NCR长190 bp,与VR-2332和LV株核苷酸序列的同源性分别为93.2%和61.1%,紧接ORF1起始密码子上游有一个保守基序:5-′UUU-AACC-3′,其作用是连接5′前导序列与各亚基因组mRNAs;3′NCR长151 nt,其后有一个长14个碱基的poly(A)尾,通过序列比较分析,发现该区核苷酸序列较为保守,与VR-2332及LV 3'NCR的核苷酸同源性分别为95.4%和78.2%,在poly(A)尾巴的上游具有一个高度保守的8核酸序列:5-′CCGAAATT-3',在病毒的复制过程中,该保守基序可能起着重要作用.非编码区的二级结构分析发现其有复杂的二级结构.

Molecular cloning and structure analysis of non-coding region of porcine reproductive and respiratory syndrome virus GS strain

According to the sequence of porcine reproductive and respiratory syndrome virus(PRRSV)VR-2332 published in GeneBank,the primers were designed to amplify the sequence of non-coding region(NCR).The results showed that the length of 5′NCR is 190 bp,and the homology at the nucleotide levels between GS and VR-2332,LV was found to be 93.2 % and 61.1 % respectively,initiation codon was followed ORF1 with a conservative sequence:5′-UUUAACC-3′,its rolewas to connect the 5′ leader sequence with the group of subunit mRNAs.The length of 3′NCR is 151 bp,followed by a long 14 base pairs of poly(A) tail,the area of nuclear glycosides acid sequence was more conservative,and the homology between GS and VR-2332,LV was 95.4 % and 78.2 %,the upstream of poly(A) tail hasa highly conservative eight nucleic acid sequence:5′-CCGAAATT-3′,play an important role in the virus replication process.The secondary structure of non-coding region is complex.