Establishing RNAi for basic research and pest control and identification of the most efficient target genes for pest control: a brief guide

Abstract

RNA interference (RNAi) has emerged as a powerful tool for knocking-down gene function in diverse taxa including arthropods for both basic biological research and application in pest control. The conservation of the RNAi mechanism in eukaryotes suggested that it should—in principle—be applicable to most arthropods. However, practical hurdles have been limiting the application in many taxa. For instance, species differ considerably with respect to efficiency of dsRNA uptake from the hemolymph or the gut. Here, we review some of the most frequently encountered technical obstacles when establishing RNAi and suggest a robust procedure for establishing this technique in insect species with special reference to pests. Finally, we present an approach to identify the most effective target genes for the potential control of agricultural and public health pests by RNAi.

The red flour beetle T. castaneum: elaborate genetic toolkit and unbiased large scale RNAi screening to study insect biology and evolution

“…The molecular basis of dsRNA uptake remains enigmatic in T. castaneum but it seems to involve Clathrin-dependent endocytosis [ 86 , 102 ]. Trials with oral uptake of dsRNA have met divergent success in different labs [ 103 ]. Whether RNAi silencing can spread from cell to cell (i.e.…”

RNA interference (RNAi) applications to the management of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae): Its current trends and future prospects

“…Lepidopterans are generally refractory to effective gene silencing by RNAi, especially when using oral delivery of dsRNA ( Dias et al, 2020 ), and this is notably associated with the inherited superior biological features in the case of S. frugiperda, which boost its adaptation against most of the utilized options, especially when they are applied in a single fashion, recognizing its direct and indirect effects in the case of RNAi as an emerging approach. Despite limiting factors, as an efficient tool in gene function, RNAi enhances susceptibility to insect pests ( Xiong et al, 2016 ; Wang et al, 2017 ; Mehlhorn et al, 2021 ) and thus could be considered a promising component in the development of integrated management against S. frugiperda . In other words, promising options have been provided to overcome the challenges associated with RNAi applications in lepidopteran S. frugiperda .…”

“…The larvae of S. frugiperda cause significant damage or losses to maize and sorghum and threaten food security in Africa ( Day et al, 2017 ; Assefa and Ayalew, 2019 ; Gichuhi et al, 2020 ). In response to pest invasion, synthetic insecticides and cultural and mechanical practices are among the suggested management methods ( Prasanna et al, 2018 ; Sisay et al, 2019 ; Mehlhorn et al, 2021 ). However, due to pest aggressiveness or superior biological characteristics, none of the aforementioned tactics achieved the required level of control, and the pest continues to cause substantial losses in most of the colonized areas.…”

“…Among emerging molecular technologies, RNA interference (RNAi) is a potential biological tool to control target insect species ( Olawale et al, 2019 ; Bai-Zhong et al, 2020 ; Gurusamy et al, 2020a ; Gregoriou et al, 2021 ; Mehlhorn et al, 2021 ; Xiao-Shuang et al, 2021 ). RNAi is a mechanism of gene instruction and an antiviral defense system in a cell, resulting in the sequence-specific degradation of messenger RNA (mRNAs) either by directing inhibitory chromatin modifications or by decreasing the stability or translation potential of the targeted mRNA ( Andrew et al, 2001 ; Liu et al, 2020 ; Mehlhorn et al, 2021 ). Double-stranded RNA (dsRNA) generated from an endogenous genomic locus or a foreign source, such as a transgene or virus, is responsible for gene silencing ( Liu et al, 2020 ; Hernández-Soto and Chacón-Cerdas, 2021 ).…”

“…RNAi-based technology shows pronounced potential for use in agriculture, particularly for the management of destructive insect pests, such as S. frugiperda ( Davis-Vogel et al, 2018 ; Bai-Zhong et al, 2020 ; Gurusamy et al, 2020b ; Mehlhorn et al, 2021 ; Wan et al, 2021). RNAi application in Lepidoptera was first reported in 2001 ( Bettencourt et al, 2002 ).…”