RNA interference (RNAi) is a valuable method for understanding the gene function and holds great potential for insect pest management. While RNAi is efficient and systemic in coleopteran insects, RNAi is inefficient in lepidopteran insects. In this study, we explored the possibility of improving RNAi in the fall armyworm (FAW), Spodoptera frugiperda cells by formulating dsRNA with Cellfectin II (CFII) transfection reagent. The CFII formulated dsRNA was protected from degradation by endonucleases present in Sf9 cells conditioned medium, hemolymph and midgut lumen contents collected from the FAW larvae. Lipid formulated dsRNA also showed reduced accumulation in the endosomes of Sf9 cells and FAW tissues. Exposing Sf9 cells and tissues to CFII formulated dsRNA caused a significant knockdown of endogenous genes. CFII formulated dsIAP fed to FAW larvae induced knockdown of iap gene, growth retardation and mortality. Processing of dsRNA into siRNA was detected in Sf9 cells and Spodoptera frugiperda larvae treated with CFII conjugated ³²P‐UTP labeled dsGFP. Overall, the present study concluded that delivering dsRNA formulated with CFII transfection reagent helps dsRNA escapes from the endosomal accumulation and improved RNAi efficiency in the FAW cells and tissues.

中文翻译：

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脂质有助于内体逃逸中的双链RNA并改善秋天粘虫Spodoptera frugiperda中的RNA干扰。

RNA干扰（RNAi）是了解基因功能的一种有价值的方法，在控制虫害方面具有巨大潜力。虽然RNAi在鞘翅目昆虫中是有效且系统的，但RNAi在鳞翅目昆虫中是无效的。在这项研究中，我们探讨了改善秋天粘虫（FAW），斜纹夜蛾（Spodoptera frugiperda）RNAi的可能性通过用Cellfectin II（CFII）转染试剂配制dsRNA来制备细胞。CFII配制的dsRNA受Sf9细胞条件培养基，从一汽幼虫收集的血淋巴和中肠管腔内容物中存在的核酸内切酶的保护，免于降解。脂质配制的dsRNA还显示出Sf9细胞和一汽组织内体中积累的减少。将Sf9细胞和组织暴露于CFII配制的dsRNA会导致内源基因的显着抑制。CFII将dsIAP配制成一汽幼虫，诱导了iap基因的敲低，生长迟缓和死亡率。在CFII偶联³²处理的Sf9细胞和草地贪夜蛾幼虫中检测到将dsRNA加工成siRNA。P‐UTP标记为dsGFP。总体而言，本研究的结论是，递送由CFII转染试剂配制的dsRNA有助于dsRNA脱离内体积累，并改善一汽细胞和组织中的RNAi效率。