Main constrains for RNAi induced by expressed long dsRNA in mouse cells

Using a system expressing dsRNA molecules and luciferase reporters, we explored factors contributing to RNAi inefficiency in mouse embryonic stem cells (ESCs) and NIH3T3 fibroblasts that could explain previous contradictions concerning mammalian RNAi. Low and poorly processive Dicer activity combined with insufficiently abundant substrates appear to be the primary reason for RNAi inefficiency.本研究借助表达双链RNA（dsRNA）分子与荧光素酶报告基因（luciferase reporters）的实验体系，对小鼠胚胎干细胞（ESCs）及NIH3T3成纤维细胞中导致RNA干扰（RNAi）效率低下的相关因素展开探究，这些因素可解释此前哺乳动物RNA干扰研究中存在的矛盾结论。 Dicer酶活性低下且催化过程性不足，加之底物丰度不足，是造成RNA干扰效率低下的主要原因。