Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
Insect Biochem Mol Biol. 2012 Feb;42(2):148-54. doi: 10.1016/j.ibmb.2011.11.007. Epub 2011 Dec 8.
RNA interference is one of the most revolutionary tools in the study of gene function, particularly in non-model systems. However, in Bombyx mori, as with many lepidopteran species, attempts at systemic RNAi have had mixed success. Gene identification and phylogenetic analyses suggest that Bombyx has the core RNAi machinery, which is necessary to undergo RNAi as a cellular response. We introduced sid genes from Caenorhabditis elegans into Bombyx BmN4 cells to enhance the uptake of dsRNA and revealed that the SID-1 protein, but not SID-2, has the ability to endow the RNAi effect with the addition of dsRNA to the medium. Observed RNAi effect was dependent on both the levels of sid-1 expression and the concentration of the dsRNA. These results suggest that SID-1 promotes the uptake of dsRNA from the medium into Bombyx cells. We generated transgenic animals that express sid-1 but have not detected significant enhancements of in vivo phenotype in response to the injection of the dsRNA into hemocoel.
RNA 干扰是研究基因功能最具革命性的工具之一，特别是在非模式系统中。然而，在桑蚕（Bombyx mori）中，与许多鳞翅目物种一样，系统性 RNAi 的尝试结果喜忧参半。基因鉴定和系统发育分析表明，桑蚕具有核心 RNAi 机制，这是细胞对 RNAi 反应所必需的。我们将秀丽隐杆线虫（Caenorhabditis elegans）的 sid 基因导入桑蚕 BmN4 细胞，以增强 dsRNA 的摄取，并发现 SID-1 蛋白而非 SID-2 具有在培养基中添加 dsRNA 赋予 RNAi 效应的能力。观察到的 RNAi 效应既依赖于 sid-1 表达水平，也依赖于 dsRNA 的浓度。这些结果表明 SID-1 促进了 dsRNA 从培养基进入桑蚕细胞的摄取。我们生成了表达 sid-1 的转基因动物，但在向血腔注射 dsRNA 时，并未检测到对体内表型的显著增强。
