Wang X, Li T, Zhao H B, Khatib H
College of Animal Science and Technology, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China.
J Dairy Sci. 2013 Oct;96(10):6525-8. doi: 10.3168/jds.2013-6873. Epub 2013 Aug 1.
The oxidized low-density lipoprotein (lectin-like) receptor 1 (OLR1) gene plays an important role in the degradation of the oxidized low-density lipoprotein, which causes damage to the arterial endothelium. Previous studies have shown that a single nucleotide polymorphism (SNP) in the 3' untranslated region (UTR) of OLR1 was associated with milk production and health traits in dairy cattle and with loin eye area and marbling depth in Qinchuan beef cattle. However, the mechanisms by which this SNP affects these traits are not well understood. MicroRNA (miRNA or mir) are small noncoding RNA that regulate gene expression by binding to target mRNA at their UTR to degrade or to repress translation of the target transcript. We hypothesized that miRNA bind to the 3' UTR of OLR1 to cause expression changes of the gene. To test this hypothesis, the Bos taurus autosome (bta)-mir-370miRNA was selected for this study based on bioinformatics prediction analysis. Two vectors that included A or C nucleotides of the 3' UTR SNP and 1 control vector were co-transfected with the vector of bta-miR-370 into human embryonic kidney 293 (HEK293) cells. Results of the dual-luciferase reporter assay showed that the activity of luciferase was significantly lower in cells transfected with the A nucleotide vector than that of the C nucleotide and control vectors. The assay also indicated that activity of miRNA bta-mir-370 was associated with a differential allelic regulation of OLR1 expression. These results imply that the 3' UTR SNP of the OLR1 gene is a strong candidate marker for selection in cattle breeding programs.
氧化型低密度脂蛋白（凝集素样）受体1（OLR1）基因在氧化型低密度脂蛋白的降解过程中发挥着重要作用，而氧化型低密度脂蛋白会对动脉内皮造成损伤。先前的研究表明，OLR1基因3'非翻译区（UTR）的单核苷酸多态性（SNP）与奶牛的产奶量和健康性状相关，也与秦川肉牛的眼肌面积和大理石花纹深度相关。然而，该SNP影响这些性状的机制尚不清楚。微小RNA（miRNA或mir）是一类小的非编码RNA，它们通过在UTR处与靶mRNA结合来调控基因表达，从而降解或抑制靶转录本的翻译。我们推测miRNA与OLR1的3'UTR结合会导致该基因表达发生变化。为了验证这一假设，基于生物信息学预测分析，本研究选择了牛（Bos taurus）常染色体（bta）-mir-370 miRNA。将包含3'UTR SNP的A或C核苷酸的两个载体以及1个对照载体与bta-miR-370载体共转染到人胚肾293（HEK293）细胞中。双荧光素酶报告基因检测结果显示，转染A核苷酸载体的细胞中荧光素酶活性显著低于转染C核苷酸载体和对照载体的细胞。该检测还表明，miRNA bta-mir-370的活性与OLR1表达的差异等位基因调控相关。这些结果表明，OLR1基因的3'UTR SNP是牛育种计划中一个强有力的选择候选标记。
