中文摘要：

为了研究家蚕bmo-miR-34（一类高度保守的miRNA）对E74基因（BmE74）的表达调控作用,首先利用生物信息学软件RNAhybrid和RNA22进行结合位点预测,然后从家蚕丝腺组织中克隆了bmo-miR-34前体序列,分别构建bmo-miR-34表达载体和靶基因BmE74 3＇UTR重组表达载体,利用双报告基因荧光检测系统在细胞水平研究bmo-miR-34对BmE74基因的转录后调控作用。生物信息学预测结果表明,BmE74 3＇UTR具有bmo-miR-34潜在结合位点;体外转染试验结果显示,与对照相比,转染bmo-miR-34重组质粒的细胞荧光素酶活性极显著下调（P〈0.01）,但是当加入人工合成的bmo-miR-34抑制物后荧光素酶活性显著上调（P〈0.01）。说明bmo-miR-34对BmE74的转录后表达具有抑制作用。

英文摘要：

In order to study the expression regulation of bmo-miR-34（ a highly conserved miRNA） on BmE74 gene in Bombyx mori,bioinformatics softwares RNAhybrid and RNA22 were used to identify the binding site in BmE74 3＇UTR.Precursor bmo-miR-34 sequence was cloned afterwards,and bmo-miR-34 recombinant expression vector and E74 3＇ UTR expression vector were constructed for transient expression assay. Dual-luciferase reporter gene system was applied to detect the role of bmo-miR-34 in the posttranscriptional regulation of BmE74 gene at the cellular level. The predicted results of bioinformatics showed that there were bmo-mir-34 potential binding sites on E74 3＇UTR. The results of transfection experiments in vitro revealed that compared with the control group the luciferase activity was significantly decreased in the Bm N cells co-transfected with bmo-miR-34 recombinant plasmid（ P〈0. 01）,and ascended distinctly after transfected with synthetic bmo-miR-34 inhibitor（ P〈0. 01）. It is indicated that bmo-miR-34 inhibits E74 gene posttranscriptional expression.