College of Animal Sciences, Zhejiang University, Hangzhou 310029, China.
Acta Biochim Biophys Sin (Shanghai). 2013 Jul;45(7):534-9. doi: 10.1093/abbs/gmt046. Epub 2013 May 3.
Internal ribosome entry site (IRES) has been widely used in genetic engineering; however, the application in silkworm (Bombyx mori) has hardly been reported. In this study, the biological activity of partial sequence of Encephalomyocarditis virus (EMCV) IRES, Rhopalosiphum padi virus (RhPV) IRES, and the hybrid of IRES of EMCV and RhPV were investigated in Spodoptera frugiperda (Sf9) cell line and silkworm tissues. The hybrid IRES of EMCV and RhPV showed more effective than EMCV IRES or RhPV IRES in promoting downstream gene expression in insect and silkworm. The activities of all IRESs in middle silk gland of silkworm were higher than those in the fat body and posterior silk gland. The hybrid IRES of EMCV and RhPV was integrated into silkworm genome by transgenic technology to test biological activity of IRES. Each of the positive transgenic individuals had significant expression of report gene EGFP. These results suggested that IRES has a potential to be used in the genetic engineering research of silkworm.
内部核糖体进入位点（IRES）已广泛应用于基因工程；然而，在蚕（家蚕）中的应用几乎没有报道。在这项研究中，研究了脑炎病毒（EMCV）IRES、禾谷缢管蚜病毒（RhPV）IRES 的部分序列以及 EMCV 和 RhPV IRES 的杂种在 Spodoptera frugiperda（Sf9）细胞系和家蚕组织中的生物活性。EMCV 和 RhPV 的杂种 IRES 在昆虫和家蚕中促进下游基因表达的效果比 EMCV IRES 或 RhPV IRES 更有效。在蚕的中肠丝腺中，所有 IRES 的活性均高于脂肪体和后丝腺。通过转基因技术将 EMCV 和 RhPV 的杂种 IRES 整合到家蚕基因组中，以测试 IRES 的生物活性。每个阳性转基因个体的报告基因 EGFP 均有显著表达。这些结果表明，IRES 在家蚕遗传工程研究中有潜在的应用价值。
