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Lebenzon JE, Toxopeus J. Knock down to level up: Reframing RNAi for invertebrate ecophysiology. Comp Biochem Physiol A Mol Integr Physiol 2024; 297:111703. [PMID: 39029617 DOI: 10.1016/j.cbpa.2024.111703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/16/2024] [Accepted: 07/16/2024] [Indexed: 07/21/2024]
Abstract
Comparative ecophysiologists strive to understand physiological problems in non-model organisms, but molecular tools such as RNA interference (RNAi) are under-used in our field. Here, we provide a framework for invertebrate ecophysiologists to use RNAi to answer questions focused on physiological processes, rather than as a tool to investigate gene function. We specifically focus on non-model invertebrates, in which the use of other genetic tools (e.g., genetic knockout lines) is less likely. We argue that because RNAi elicits a temporary manipulation of gene expression, and resources to carry out RNAi are technically and financially accessible, it is an effective tool for invertebrate ecophysiologists. We cover the terminology and basic mechanisms of RNA interference as an accessible introduction for "non-molecular" physiologists, include a suggested workflow for identifying RNAi gene targets and validating biologically relevant gene knockdowns, and present a hypothesis-testing framework for using RNAi to answer common questions in the realm of invertebrate ecophysiology. This review encourages invertebrate ecophysiologists to use these tools and workflows to explore physiological processes and bridge genotypes to phenotypes in their animal(s) of interest.
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Affiliation(s)
- Jacqueline E Lebenzon
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4.
| | - Jantina Toxopeus
- Department of Biology, St. Francis Xavier University, 2321 Notre Dame Ave, Antigonish, NS, Canada B2G 2W5
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2
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Koo J, Palli SR. Recent advances in understanding of the mechanisms of RNA interference in insects. INSECT MOLECULAR BIOLOGY 2024. [PMID: 38957135 DOI: 10.1111/imb.12941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 06/20/2024] [Indexed: 07/04/2024]
Abstract
We highlight the recent 5 years of research that contributed to our understanding of the mechanisms of RNA interference (RNAi) in insects. Since its first discovery, RNAi has contributed enormously as a reverse genetic tool for functional genomic studies. RNAi is also being used in therapeutics, as well as agricultural crop and livestock production and protection. Yet, for the wider application of RNAi, improvement of its potency and delivery technologies is needed. A mechanistic understanding of every step of RNAi, from cellular uptake of RNAi trigger molecules to targeted mRNA degradation, is key for developing an efficient strategy to improve RNAi technology. Insects provide an excellent model for studying the mechanism of RNAi due to species-specific variations in RNAi efficiency. This allows us to perform comparative studies in insect species with different RNAi sensitivity. Understanding the mechanisms of RNAi in different insects can lead to the development of better strategies to improve RNAi and its application to manage agriculturally and medically important insects.
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Affiliation(s)
- Jinmo Koo
- Department of Entomology, Gatton-Martin College of Agriculture, University of Kentucky, Lexington, Kentucky, USA
| | - Subba Reddy Palli
- Department of Entomology, Gatton-Martin College of Agriculture, University of Kentucky, Lexington, Kentucky, USA
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3
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Liu X, Gao Y, Li Y, El Wakil A, Moussian B, Zhang J. Syntaxin5 is essential for survival by ensuring midgut epithelial homeostsis and regulating feeding in Locusta migratoria. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 202:105934. [PMID: 38879326 DOI: 10.1016/j.pestbp.2024.105934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/13/2024] [Accepted: 04/26/2024] [Indexed: 06/19/2024]
Abstract
Syntaxin5 (Syx5) belongs to SNAREs family, which play important roles in fusion of vesicles to target membranes. Most of what we know about functions of Syx5 originates from studies in fungal or vertebrate cells, how Syx5 operates during the development of insects is poorly understood. In this study, we investigated the role of LmSyx5 in the gut development of the hemimetabolous insect Locusta migratoria. LmSyx5 was expressed in many tissues, with higher levels in the gut. Knockdown of LmSyx5 by RNA interference (RNAi) considerably suppressed feeding in both nymphs and adults. The dsLmSyx5-injected locusts lost body weight and finally died at a mortality of 100%. Furthermore, hematoxylin-eosin staining indicated that the midgut is deformed in dsLmSyx5-treated nymphs and the brush border in midgut epithelial cells is severely damaged, suggesting that LmSyx5 is involved in morphogenesis of the midgut. TEM further showed that the endoplasmic reticulum of midgut cells have a bloated appearance. Taken together, these results suggest that LmSyx5 is essential for midgut epithelial homeostsis that affects growth and development of L. migratoria. Thus, Syx5 is a promising RNAi target for controlling L. migratoria, and even other pests.
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Affiliation(s)
- Xiaojian Liu
- Shanxi Key Laboratory of Nucleic Acid Biopesticides; Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Ya Gao
- Shanxi Key Laboratory of Nucleic Acid Biopesticides; Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Yao Li
- Shanxi Key Laboratory of Nucleic Acid Biopesticides; Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Abeer El Wakil
- Faculty of Education, Department of Biological and Geological Sciences, Alexandria University, Alexandria, Egypt
| | - Bernard Moussian
- INRAE, CNRS, Université Côte d'Azur, Institut Sophia Agrobiotech, Sophia Antipolis, France
| | - Jianzhen Zhang
- Shanxi Key Laboratory of Nucleic Acid Biopesticides; Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China.
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Niu J, Chen R, Wang JJ. RNA interference in insects: the link between antiviral defense and pest control. INSECT SCIENCE 2024; 31:2-12. [PMID: 37162315 DOI: 10.1111/1744-7917.13208] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/27/2023] [Accepted: 04/10/2023] [Indexed: 05/11/2023]
Abstract
RNA interference (RNAi) is a form of gene silencing triggered by double-stranded RNA (dsRNA) that operates in all eukaryotic cells. RNAi has been widely investigated in insects to determine the underlying molecular mechanism, to investigate its role in systemic antiviral defense, and to develop strategies for pest control. When insect cells are infected by viruses, viral dsRNA signatures trigger a local RNAi response to block viral replication and generate virus-derived DNA that confers systemic immunity. RNAi-based insect pest control involves the application of exogenous dsRNA targeting genes essential for insect development or survival, but the efficacy of this approach has limited potency in many pests through a combination of rapid dsRNA degradation, inefficient dsRNA uptake/processing, and ineffective RNAi machinery. This could be addressed by dsRNA screening and evaluation, focusing on dsRNA design and off-target management, as well as dsRNA production and delivery. This review summarizes recent progress to determine the role of RNAi in antiviral defense and as a pest control strategy in insects, addressing gaps between our fundamental understanding of the RNAi mechanism and the exploitation of RNAi-based pest control strategies.
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Affiliation(s)
- Jinzhi Niu
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing, China
| | - Ruoyu Chen
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing, China
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5
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Moescheid MF, Puckelwaldt O, Beutler M, Haeberlein S, Grevelding CG. Defining an optimal control for RNAi experiments with adult Schistosoma mansoni. Sci Rep 2023; 13:9766. [PMID: 37328492 PMCID: PMC10276032 DOI: 10.1038/s41598-023-36826-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/10/2023] [Indexed: 06/18/2023] Open
Abstract
In parasites such as Schistosoma mansoni, gene knockdown by RNA interference (RNAi) has become an indispensable tool for functional gene characterization. To distinguish target-specific RNAi effects versus off-target effects, controls are essential. To date, however, there is still no general agreement about suitable RNAi controls, which limits the comparability between studies. To address this point, we investigated three selected dsRNAs for their suitability as RNAi controls in experiments with adult S. mansoni in vitro. Two dsRNAs were of bacterial origin, the neomycin resistance gene (neoR) and the ampicillin resistance gene (ampR). The third one, the green fluorescent protein gene (gfp), originated from jellyfish. Following dsRNA application, we analyzed physiological parameters like pairing stability, motility, and egg production as well as morphological integrity. Furthermore, using RT-qPCR we evaluated the potential of the used dsRNAs to influence transcript patterns of off-target genes, which had been predicted by si-Fi (siRNA-Finder). At the physiological and morphological levels, we observed no obvious changes in the dsRNA treatment groups compared to an untreated control. However, we detected remarkable differences at the transcript level of gene expression. Amongst the three tested candidates, we suggest dsRNA of the E. coli ampR gene as the most suitable RNAi control.
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Affiliation(s)
- Max F Moescheid
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Oliver Puckelwaldt
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Mandy Beutler
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Simone Haeberlein
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Christoph G Grevelding
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany.
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He W, Xu W, Fu K, Guo W, Kim DS, Zhang J. Positional effects of double-stranded RNAs targeting β-Actin gene affect RNA interference efficiency in Colorado potato beetle. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 184:105121. [PMID: 35715059 DOI: 10.1016/j.pestbp.2022.105121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Pesticide resistance in pests drives the development of RNA interference (RNAi)-based technology as a novel approach for pest control. To investigate the effects of the positional dependency of double-stranded RNAs (dsRNAs), we newly designed four different 200 bp dsRNAs targeting Colorado potato beetle (CPB) β-Actin gene, termed as dsACT200-1 to dsACT200-4, to compare their insecticidal activity to CPB larvae together with our previously used 200 bp and 700 bp dsRNAs (dsACT200 and dsACT700), respectively (He et al., 2020a). Each of dsRNAs harbors different numbers of expected siRNAs predicted by sequence-based prediction platform, dsACT200 and dsACT200-2 have a relatively higher number of siRNA than other 200 bps dsRNAs. When CPB larvae were fed with in vitro synthesized dsRNA-painted potato leaves, all the tested dsRNAs showed significant effects to protect against CPB larvae. Combined with the survival rate of CPB larvae, β-Actin gene expression level and the surviving CPB larvae weight, various positional dsRNAs from the same allele showed different plant protection activity against CPB larvae and partially correlated with the predicted siRNA numbers and distribution on the target sequence. This study suggests the specific allelic locus for rational dsRNA design triggering RNAi efficiency for target gene silencing is an essential factor in enhancing the insecticidal activity.
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Affiliation(s)
- Wanwan He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China; Wuhan Academy of Agricultural Sciences, Wuhan 430070, China
| | - Wenbo Xu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Kaiyun Fu
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830000, China
| | - Wenchao Guo
- Institute of Microbial Application, Xinjiang Academy of Agricultural Sciences, Urumqi 830000, China
| | - Dae Sung Kim
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Jiang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
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Zhang CS, Sun LL, Xie JM, Cao CW. RNAi-based functional analysis of bursicon genes related to wing expansion in gypsy moths. JOURNAL OF INSECT PHYSIOLOGY 2022; 139:104398. [PMID: 35537524 DOI: 10.1016/j.jinsphys.2022.104398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/16/2022] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
Bursicon is a heterodimeric neuropeptide composed of Burs-α and Burs-β subunits that plays an important role in cuticle tanning and wing expansion in insects. In this study, full-length cDNAs of Burs-α (LdBurs-α) and Burs-β (LdBurs-β) genes were identified in gypsy moth (Lymantria dispar) and cloned. The 480 bp and 420 bp open reading frames (ORFs) encode 159 and 129 amino acid polypeptides, respectively. LdBurs-α and LdBurs-β have 11 conserved cysteine residues, and LdBurs-α and LdBurs-β genes were expressed during all developmental stages according to quantitative reverse transcription PCR (qRT-PCR), with highest expression in the egg stage. High expression levels were also detected in the haemolymph, cuticle and head. To explore the physiological functions of LdBurs-α and LdBurs-β, the genes were knocked down in larvae and pupae using RNA interference (RNAi), and expression levels of LdBurs-α and LdBurs-β were decreased by 42.26-80.09%. Wing defects were observed in L. dispar pupae following Ldbursion silencing, with a phenotypic percentage ranging from 10.17% to 15.00%. RNAi-mediated knockdown of Ldbursicon prevented the expansion of male and female L. dispar adult wings, with malformation rates ranging from 6.38% and 30.00% to 57.69% and 69.23%, but no cuticle tanning defects were observed in pupae or adults. The results indicate that bursicon plays a key role in wing expansion in L. dispar adults, making it a potentially novel molecular target for insecticide-based control of this pest species.
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Affiliation(s)
- Chen-Shu Zhang
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Li-Li Sun
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Jia-Ming Xie
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Chuan-Wang Cao
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, PR China.
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Fan Y, Abbas M, Liu X, Wang Y, Song H, Li T, Ma E, Zhu KY, Zhang J. Increased RNAi Efficiency by dsEGFP-Induced Up-Regulation of Two Core RNAi Pathway Genes (OfDicer2 and OfAgo2) in the Asian Corn Borer (Ostrinia furnacalis). INSECTS 2022; 13:insects13030274. [PMID: 35323572 PMCID: PMC8948962 DOI: 10.3390/insects13030274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/04/2022] [Accepted: 03/06/2022] [Indexed: 12/07/2022]
Abstract
Simple Summary RNA interference (RNAi) has shown great potentials as a novel technology for insect pest management. However, numerous studies have shown that the efficiency of RNAi varies substantially among different insect species. For example, as a major insect pest of corn, the Asian corn borer (Ostrinia furnacalis) showed very low RNAi efficiency. Therefore, it is necessary to develop new strategies for enhancing RNAi efficiency in insects with low RNAi efficiency. In this study, six core RNAi pathway genes were identified and characterized from O. furnacalis transcriptome database. After dsEGFP was injected into O. furnacalis, the expression of the core RNAi pathway genes (OfDicer2 and OfAgo2) was significantly up-regulated in response to the exposure of dsEGFP. As a result, the RNAi efficiency against the target genes in certain tissues of O. furnacalis was significantly improved. These results suggest that RNAi efficiency can be improved by inducing the expression of key RNAi pathway genes in O. furnacalis. Abstract RNA interference (RNAi) is a sequence-specific gene silencing mechanism that holds great promise for effective management of agricultural pests. Previous studies have shown that the efficacy of RNAi varies among different insect species, which limits its wide spread application in the field of crop protection. In this study, we identified and characterized six core RNAi pathway genes including OfDicer1, OfDicer2, OfR2D2, OfAgo1, OfAgo2, and OfAgo3 from the transcriptomic database of the Asian corn borer (Ostrinia furnacalis). Domain analysis showed that the six deduced proteins contained the necessary functional domains. Insect developmental stage- and tissue-specific expression analysis showed that five genes were expressed in all the stages and tissues examined except OfAgo3, which showed low expression in larvae, and high expression in pupae and adults and in the midgut. RT-qPCR was performed to examine the response of these six genes to exogenous double-stranded RNA (dsRNA). Interestingly, the transcript levels of OfDicer2 and OfAgo2 were significantly enhanced after the injection of dsEGFP at different time points and tissues investigated. Consequently, the RNAi efficiency in targeting the insect endogenous genes can be greatly enhanced in the hemolymph or midgut. Taken together, our investigations suggest that RNAi efficiency can be enhanced by pre-injection of dsRNA to induce the RNAi core machinery genes, which could be a useful strategy to improving RNAi efficiency for studying gene functions under laboratory conditions.
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Affiliation(s)
- Yunhe Fan
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
- College of Life Science, Shanxi University, Taiyuan 030006, China
| | - Mureed Abbas
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
- Modern Research Center for Traditional Chinese Medicine, The Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Xiaojian Liu
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
| | - Yanli Wang
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
| | - Huifang Song
- Faculty of Biological Science and Technology, Changzhi University, Changzhi 046000, China;
| | - Tao Li
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
| | - Enbo Ma
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
| | - Kun Yan Zhu
- Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA
- Correspondence: (K.Y.Z.); (J.Z.)
| | - Jianzhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.F.); (M.A.); (X.L.); (Y.W.); (T.L.); (E.M.)
- Correspondence: (K.Y.Z.); (J.Z.)
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