利用生物信息学方法预测家蚕核型多角体病毒基因组编码的miRNA  

Prediction of Bombyx mori Nucleopolyhedrosis Virus Genome Encoded microRNAs by Means of Bioinformatics

作　　者：陈蔚[1] 黄勇[1] 赵巧玲[1,2] 宋菲[1] 裘智勇[1,2] 夏定国[1,2] 沈兴家[1,2] 

机构地区：[1]江苏科技大学,江苏镇江212003 [2]中国农业科学院蚕业研究所,江苏镇江212018

出　　处：《蚕业科学》2011年第5期818-824,共7页ACTA SERICOLOGICA SINICA

基　　金：国家自然科学基金项目(No.31072083);"十二五"国家科技支撑计划项目(No.2011BAD33B04)

摘　　要：microRNAs(miRNAs)是长度为18～25 nt的非蛋白质编码小RNA分子,可以通过抑制有关基因mRNA的翻译从而调控机体的生长发育、疾病发生等过程。在很多病毒中发现有miRNA的存在,这些miRNA可能在病毒基因的表达以及与宿主的相互作用中发挥作用。利用vMir软件预测家蚕核型多角体病毒(BmNPV)基因组可能编码的miRNA前体序列,对BmNPV基因组扫描分析后,得到7条能形成发夹结构的可能是miRNA的候选前体序列。以BmNPV添食感染5龄起蚕,72 h后取幼虫血淋巴提取总RNA,对这7条序列进行反转录PCR验证,其中扩增出的5条序列在BmNPV基因组中有相同的序列,推测这5条序列为BmNPV基因组编码的miRNA前体序列。进一步分析5条miRNA前体序列的发夹结构,并用反转录PCR的方法验证其成熟体序列,结果在5条miRNA前体序列共扩增出6条在BmNPV基因组中有相同序列的成熟体序列,它们分别位于不同的ORF之间,是BmNPV基因组编码的miRNA。利用在线靶基因预测程序RNAhybrid和RNA22预测到6条miRNA在BmNPV中的13个可能的靶基因,其中有6个靶基因是病毒的结构蛋白基因,2个为晚期表达因子基因,5个为未知功能基因。推测这些BmNPV基因组编码的miRNA可能与病毒感染宿主有关。microRNAs（miRNAs） are small（18 ~25 nucleotides） non-coding RNAs.They can inhibit the translation of relevant genes＇ mRNA to regulate organism＇s growth,development,and disease occurrence etc.miRNAs have been detected in many virus species.They probably play important roles in the expression of viral genes and in the interaction between virus and host.We applied the vMir software to predict potential miRNA precursor sequences encoded by Bombyx mori nucleopolyhedrovirus（BmNPV） genome.After a scanning analysis to the genome of BmNPV,7 candidate miRNA precursors which are capable of forming hairpin structure were obtained.The 5th instar newly exuviated larvae of Bombyx mori were infected orally with BmNPV.The hemolymph was harvested from the BmNPV-infected larvae 72 h post infection for total RNA extraction.Reverse transcription-PCR（RT-PCR） of these 7 sequences verified that 5 se-quences had identical sequences in BmNPV genome,suggesting that these 5 sequences are miRNA precursor sequences encoded by BmNPV genome.These 5 precursor sequences were subject to further analysis on their hairpin structure and verification of their mature miRNA sequences by RT-PCR.The results showed that these 5 precursor sequences yielded a total of 6 amplified mature miRNA sequences that had identical sequences in BmNPV genome.They were located between different ORFs,being BmNPV genome encoded miRNAs.By using online RNA target gene prediction programs RNAhybrid combined with RNA22 software,viral target genes of the above 6 BmNPV miRNAs were analyzed and 13 potential viral target genes were predicted,among which 6 were coding genes of structural protein,2 of late expression factor,and the rest 5 of unknown function.It is considered that BmNPV genome encoded miRNAs are related to viral infection to host.

关 键 词：家蚕核型多角体病毒 小RNA 生物信息学 反转录PCR 靶基因 

分 类 号：S884.51[农业科学—特种经济动物饲养] Q78[农业科学—畜牧兽医]