|YOON, JUNE-SUN - Jeonbuk National University|
|AHN, SEUNG-JOON - Mississippi State University|
Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2023
Publication Date: 1/12/2023
Citation: Yoon, J., Ahn, S., Choi, M.Y. 2023. Selection and comparative gene expression of midgut-specific targets for Drosophila suzukii. Insects. 14(1). Article 76. https://doi.org/10.3390/insects14010076.
Interpretive Summary: Drosophila suzukii, spotted-wing drosophila (SWD), a major pest of small fruits and cherries is often managed with conventional insecticides. RNA interference (RNAi) technology has been investigated to develop an alternative control method for SWD. Our previous RNAi work showed that the RNAi efficacy on SWD was limited because double-stranded RNA (dsRNA) (= RNAi material) was degraded by the midgut nuclease (= dsRNA enzyme) before passing through the midgut membrane of the fly. To overcome this obstacle, RNAi directly targets the midgut genes, thus eliminating the need for dsRNA to pass through the midgut membrane. The primary focus of this study is to identify the adult midgut's genes for RNAi targets. We found that 1,921 genes were upregulated, and 1,834 genes were downregulated in the midgut using transcriptomic analysis. We chose ten midgut-specific upregulated genes involved in various biological functions and confirmed the gene expressions. The midgut transcriptome data might be useful in the selection of RNAi targets to develop SWD control methods.
Technical Abstract: Spotted-wing drosophila (SWD), Drosophila suzukii, is a destructive and invasive pest that attacks most small fruits and cherries. The current management for SWD involves the use of conventional insecticides. In an effort to develop a biologically-based control option, the application of RNA interference (RNAi) has been investigated. To develop an RNAi approach, suitable targets must be identified and an efficient delivery method must be developed for introducing the double-stranded RNA (dsRNA) in the midgut. In D. suzukii, we found that dsRNA nucleases are actively degrading dsRNA molecules in the midgut. In this study, we focused on identifying biological targets including RNAi in the fly midgut. The profile of midgut-specific genes was analyzed and compared with the genes in the whole body using transcriptomic analysis. Differential gene expression analysis revealed that 1,921 contigs were upregulated and 1,834 contigs were downregulated in the midgut when compared to genes from other body tissues. We chose ten midgut-specific upregulated genes to investigate as potential biological targets for RNAi, including several G protein-coupled receptors (GPCRs) because insect GPCRs offer great potential for next-generation pest management. Target gene expression was validated using qRT-PCR. In particular, the midgut GPCRs of the diuretic hormone 31 (DH31), neuropeptide F (NPF), toll-9, and adhesion may be good candidates for RNAi or receptor interference (Receptor-i) to develop novel methods for controlling D. suzukii in the future.