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Tabara M, Harada M, Kuriyama K, Sakamoto T, Takeda A, Fukuhara T, Tabunoki H. Biochemical characterization of Bombyx mori Dicer-2 that dices double-stranded RNAs into 20-nt small RNA. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 116:e22118. [PMID: 38713637 DOI: 10.1002/arch.22118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/14/2024] [Accepted: 04/24/2024] [Indexed: 05/09/2024]
Abstract
We detected enzymatic activity that generates 20-nucleotide (nt) RNA from double-stranded RNAs (dsRNAs) in crude extracts prepared from various silkworm (Bombyx mori) organs. The result using knocked-down cultured cells indicated that this dicing activity originated from B. mori Dicer-2 (BmDcr2). Biochemical analyses revealed that BmDcr2 preferentially cleaves 5'-phosphorylated dsRNAs at the 20-nt site-counted from the 5'-phosphorylated end-and required ATP and magnesium ions for the dicing reaction. This is the first report of the biochemical characterization of Dicer-2 in lepidopteran insects. This enzymatic property of BmDcr2 in vitro is consistent with the in vivo small interfering RNA profile in virus-infected silkworm cells.
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Affiliation(s)
- Midori Tabara
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, Shiga, Japan
| | - Mayuko Harada
- Department of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Kazunori Kuriyama
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Takuma Sakamoto
- Department of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Atsushi Takeda
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, Shiga, Japan
| | - Toshiyuki Fukuhara
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Hiroko Tabunoki
- Department of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
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Mehlhorn S, Hunnekuhl VS, Geibel S, Nauen R, Bucher G. Establishing RNAi for basic research and pest control and identification of the most efficient target genes for pest control: a brief guide. Front Zool 2021; 18:60. [PMID: 34863212 PMCID: PMC8643023 DOI: 10.1186/s12983-021-00444-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/04/2021] [Indexed: 11/14/2022] Open
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.
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Affiliation(s)
- Sonja Mehlhorn
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Vera S Hunnekuhl
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Sven Geibel
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
| | - Ralf Nauen
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany.
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Peng Y, Wang K, Chen J, Wang J, Zhang H, Ze L, Zhu G, Zhao C, Xiao H, Han Z. Identification of a double-stranded RNA-degrading nuclease influencing both ingestion and injection RNA interference efficiency in the red flour beetle Tribolium castaneum. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 125:103440. [PMID: 32771566 DOI: 10.1016/j.ibmb.2020.103440] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/08/2020] [Accepted: 07/20/2020] [Indexed: 05/10/2023]
Abstract
RNA interference (RNAi) efficiency dramatically varies among different insects and among administration methods. Numerous studies have revealed that a poor RNAi response is usually associated with a high double-stranded RNA (dsRNA)-degrading activity. Using the red flour beetle Tribolium castaneum, we conducted genome-wide identification of genes encoding dsRNA-degrading nucleases of the DNA/RNA non-specific endonuclease superfamily. To achieve a robust RNAi response in T. castaneum, four dsRNase genes were identified in the genome that seemed to be the potential factors reducing RNAi efficacy. Analysis of biochemical properties revealed that optimal conditions for the dsRNA-degrading activity were alkaline (pH 8.0) in the absence of Mg2+ at 37 °C. The dsRNA-degrading activity was predominantly present in the gut, and via heterologous expression and RNAi experimentation, gut-specific TcdsRNase1 was confirmed as the major nuclease performing dsRNA degradation. After a knockdown of the TcdsRNase1 nuclease activity, RNAi efficiency improved from 38.6% to 58.9% and from 20.9% to 53.9% for injection and ingestion of dsRNA, respectively. Our results contribute to a comprehensive understanding of the mechanisms influencing dsRNA stability and even RNAi efficiency in T. castaneum and point to a good method for improving RNAi efficiency through downregulation of the relevant nuclease activity.
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Affiliation(s)
- Yingchuan Peng
- Institute of Entomology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Kangxu Wang
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiasheng Chen
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jinda Wang
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hainan Zhang
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Longji Ze
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guanheng Zhu
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington KY, 40546, USA
| | - Chunqing Zhao
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haijun Xiao
- Institute of Entomology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Zhaojun Han
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
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Peng Y, Wang K, Fu W, Sheng C, Han Z. Biochemical Comparison of dsRNA Degrading Nucleases in Four Different Insects. Front Physiol 2018; 9:624. [PMID: 29892232 PMCID: PMC5985623 DOI: 10.3389/fphys.2018.00624] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/08/2018] [Indexed: 12/21/2022] Open
Abstract
Double stranded RNAs (dsRNA) degrading nuclease is responsible for the rapid degradation of dsRNA molecules, and thus accounts for variations in RNA interference (RNAi) efficacy among insect species. Here, the biochemical properties and tissue-specific activities of dsRNA degrading nucleases in four insects (Spodoptera litura, Locusta migratoria, Periplaneta americana, and Zophobas atratus) from different orders were characterized using a modified assay method. The results revealed that all insect dsRNA degrading nucleases tested showed high activity in alkaline environments at optimal Mg2+ concentrations and elevated temperatures. We also found that enzymes from different insects varied in terms of their optimal reaction conditions and kinetic parameters. Whole body enzyme activity differed dramatically between insect species, although enzymes with higher substrate affinities (lower Km) were usually balanced by a smaller Vmax to maintain a proper level of degradative capacity. Furthermore, enzyme activities varied significantly between the four tested tissues (whole body, gut, hemolymph, and carcass) of the insect species. All the insects tested showed several hundred-fold higher dsRNA degrading activity in their gut than in other tissues. Reaction environment analysis demonstrated that physiological conditions in the prepared gut fluid and serum of different insects were not necessarily optimal for dsRNA degrading nuclease activity. Our data describe the biochemical characteristics and tissue distributions of dsRNA degrading activities in various insects, not only explaining why oral delivery of dsRNA often produces lower RNAi effects than injection of dsRNA, but also suggesting that dsRNA-degrading activities are regulated by physiological conditions. These results allow for a better understanding of the properties of dsRNA degrading nucleases, and will aid in the development of successful RNAi strategies in insects.
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Affiliation(s)
| | | | | | | | - Zhaojun Han
- The Agricultural Ministry Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Joga MR, Zotti MJ, Smagghe G, Christiaens O. RNAi Efficiency, Systemic Properties, and Novel Delivery Methods for Pest Insect Control: What We Know So Far. Front Physiol 2016; 7:553. [PMID: 27909411 PMCID: PMC5112363 DOI: 10.3389/fphys.2016.00553] [Citation(s) in RCA: 251] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/03/2016] [Indexed: 01/01/2023] Open
Abstract
In recent years, the research on the potential of using RNA interference (RNAi) to suppress crop pests has made an outstanding growth. However, given the variability of RNAi efficiency that is observed in many insects, the development of novel approaches toward insect pest management using RNAi requires first to unravel factors behind the efficiency of dsRNA-mediated gene silencing. In this review, we explore essential implications and possibilities to increase RNAi efficiency by delivery of dsRNA through non-transformative methods. We discuss factors influencing the RNAi mechanism in insects and systemic properties of dsRNA. Finally, novel strategies to deliver dsRNA are discussed, including delivery by symbionts, plant viruses, trunk injections, root soaking, and transplastomic plants.
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Affiliation(s)
- Mallikarjuna R Joga
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University Gent, Belgium
| | - Moises J Zotti
- Department of Crop Protection, Molecular Entomology, Federal University of Pelotas Pelotas, Brazil
| | - Guy Smagghe
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University Gent, Belgium
| | - Olivier Christiaens
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University Gent, Belgium
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