【作者】 刘惠芬； 李云芝； 衣葵花； 刘文光； 郭光； 聂磊； 王娜； 于振诚；

【Author】 LIU Hui-Fen;LI Yun-Zhi;YI Kui-Hua;LIU Wen-Guang;GUO Guang;NIE Lei;WANG Na;YU Zhen-Cheng;The Sericultural Research Institute of Shandong;

【机构】 山东省蚕业研究所；

【摘要】 斜纹夜蛾核型多角体病毒Ⅱ型分离株(Splt NPVⅡ)是近年来发现的一种繁殖率和毒力极强的新的病毒变异株,该病毒基因组DNA含有7个同源重复区。从Splt NPVⅡ基因组中克隆了hr4,进行了全序列测定和结构功能分析。序列分析发现,hr4大小为2212bp,位于基因组56264-58475bp,ORF57-ORF58之间。hr4含8个64 bp不完全回文序列,回文基序的中心均含有一个Pvu I限制性酶切位点,并且存在3个正向或反向互补的重复序列以及多个与病毒基因组DNA复制相关的motif基序。瞬时表达分析表明,hr4在野生型病毒Splt NPVⅡ感染和未感染的细胞中均具有增强早期基因ie1启动子活性功能;实时荧光定量PCR结果显示,hr4在野生型病毒Splt NPVⅡ作为辅助病毒时,具有复制起始原点功能。上述研究结果表明,Splt NPVⅡhr4具有复制起始原点和增强子双功能的作用,该研究将会进一步加深和丰富对杆状病毒增殖机制的认识。更多还原

【Abstract】 Spodoptera litura NucleopolyhedrovirusⅡ(Splt MNPVⅡ)is a kind of new virus variants with strong reproduction rate and highly virulent. In the genomic DNA of Splt MNPVⅡ, seven homologous regions(hrs)were identified. The hr4 was cloned and sequenced, and its structure-function was analyzed. The length of hr4 is 2212 bp, and it locates in the genome of 56264-58475 bp between ORF57-ORF58. The hr4 consists of 8 64-bp imperfect palindromes containing a Pvu I site in the center and 3 direct and inverted repetitive sequence and multiple motifs which related to the replication of genomic DNA of virus. A transient expression assay demonstrated that the expression of Splt NPVⅡ-ie1 promoter-driven luciferase gene was enhanced by hr4 in both infected and uninfected Spli221 cells. Real-time PCR confirmed the hr4 could function as ori of viral DNA replication in infected cells. The study indicated that Splt NPVⅡhr4 is bifunctional, having both ori and enhancer activities for transcription. The recognition of proliferative mechanism of baculovirus in the host can be developed by our research.更多还原