Application of Double-stranded RNA (dsRNA) Produced by E. coli HT115 (DE3) and Vector L4440 in Reverse Genetics Studies in Insects

RNA interference is a cellular process for regulating gene expression by double-stranded RNA (dsRNA). In the past two decades, this cellular process has been used as a tool for the temporary knockdown of gene expression to study gene function in reverse genetics studies. In this regard, double-stranded RNA has been made in various ways and used to knock down the corresponding gene. In the past decade, the potential of the technique for insect pest management has become clear although the costs associated with the production of dsRNA are not reasonable and affordable for such use. Even on the laboratory scale, making the dsRNA for RNAi experiments using dsRNA production kits is not affordable for most researchers and laboratories. Therefore, researchers are focused on ways to make the production of dsRNA more affordable. The conventional method of carrying out RNAi experiments uses a vector called pL4440 and a host strain of E. coli called HT115 (DE3) to make dsRNA. This method which is called bacterium-mediated RNAi (bmRNAi) has been used successfully for the knockdown of many genes in Caenorhabditis elegans. However, the number of studies that used this technique so far in insects is limited to a few major insect orders, namely Coleoptera, Lepidoptera, Diptera, and Hymenoptera. In this review, the bmRNAi technique is discussed in detail and the studies successfully conducted using this technique are introduced.