家蚕传染性软化病病毒(桐乡株)5′端非编码区基因的克隆及序列分析  

Cloning and Sequence Analysis of 5′ Non-coding Region of Bombyx mori Infectious Flacherie Virus Isolated in Tongxiang,China

作　　者：李明乾[1] 苘娜娜[1] 蔡顺风[1] 陈孝学[1] 金伟[1] 鲁兴萌[1] 

机构地区：[1]浙江大学动物科学学院无脊椎动物病理学研究室,杭州310029

出　　处：《蚕业科学》2009年第1期84-89,共6页ACTA SERICOLOGICA SINICA

基　　金：国家高技术研究发展计划"863"项目(编号2006AA10A-119)

摘　　要：为了探讨家蚕传染性软化病病毒的复制与翻译机制,利用cDNA 5′末端快速扩增(5′-RACE)技术获得了家蚕传染性软化病病毒桐乡分离株(Bombyxmoriinfectious flacherie virus,BmIFV-2)的5′端非编码区(non-coding region,NCR)。序列比较分析发现:BmIFV-2的5′-NCR由155个核苷酸组成,A+U含量达60.64%,其中包含1个起始密码子AUG;与坂城分离株(BmIFV-1)的5′-NCR相比,BmIFV-2的5′-NCR在5′末端缺少1个核苷酸,但核苷酸识别率为100%(即单核苷酸变异率为0),而且这个缺少的核苷酸并不影响其5′-NCR的二级结构。与已经证实具有内部核糖体进入位点(internal ribosome entry site,IRES)活性的Iflavirus属的2种病毒EoPV(Ectropis obliquapicor-na-like virus)和VDV-1(Varroa destructorvirus 1)的5′-NCR相比,BmIFV的5′-NCR可能也具有IRES活性。In this study, the 5＇ non-coding region （NCR） of Bombyx mori infectious flacherie virus isolated in Tongxiang, China （BmlFV-2） was obtained through 5＇-RACE. Sequence analysis revealed that BmlFV-2 has 155 nucleotides in its 5＇-NCR, which contains an AUG, and the content of A ＋U reaches 60.64%. Although the 5＇-NCR of BmlFV-2 was one nucleotide shorter than that of the strain isolated in Japan （ BmlFV-1 ）, the nu- cleotide recognition ratio was 100% （i. e., no single-nucleotide polymorphism）. In addition, the absent nucleotide did not affect the secondary structure of 5＇-NCR. Sequence comparison with 5＇-NCR of two viruses, EoPV and VDV-1 from genus Iflavirus, indicated that the 5＇-NCR of BmtFV might have IRES （internal ribosome entry site） activity as these two viruses.

关 键 词：家蚕 传软性软化病毒 5′端非编码区 序列分析 

分 类 号：S884.53[农业科学—特种经济动物饲养] Q78[农业科学—畜牧兽医]