Dissecting of Environmental RNAi mechanism in insect

• Project/Area Number: 16K18690
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Applied biochemistry
• Research Institution: Kawasaki University of Medical Welfare (2018-2019); Chubu University (2016-2017)
• Principal Investigator: MIYATA Keita 川崎医療福祉大学, 医療技術学部, 講師 (90736290)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: RNA干渉 / 害虫防除 / dsRNA / 腸管切片 / RNAi / double stranded RNA / 昆虫 / 発現制御 / 細胞・組織

Outline of Final Research Achievements

RNA interference (RNAi), a phenomenon in which silencing of gene expression is triggered by a double-stranded RNA (dsRNA) molecule, has been established as useful tool for reverse genetics studies in many organisms. RNAi triggered via injection of dsRNA is widely used in many insects. RNAi has been demonstrated in some insects when fed with dsRNA. This discovery indicates the possibility of environmental RNAi (e-RNAi), which can potentially be used in RNAi-based pest management. However, information of insect e-RNAi is a little. In this study, to dissect insect e-RNAi investigated whether several insects display e-RNAi. The result showed some insects did not display e-RNAi, and dsRNA was unstable in those midgut juice. e-RNAi was slightly induced in insect which did not display e-RNAi, when fed improved dsRNA for degradation by midgut juice. These results provide the definitive relation between stability of dsRNA for midgut juice and displaying of robust e-RNAi in insect.

Academic Significance and Societal Importance of the Research Achievements

RNA干渉は、外来から二本鎖のRNA（dsRNA）が細胞内に侵入した際、遺伝子の発現が特異的に抑制される現象である。数種類の昆虫がdsRNAを餌と共に摂取することでRNA干渉が起こること（e-RNA干渉）が報告され、害虫防除への応用に注目が集まっている。本研究では、昆虫がdsRNAを餌と共に摂取した際、e-RNA干渉が起こるためにはdsRNAが安定した状態で吸収される必要があることを明らかとした。本研究成果は、化学物質の使用の減少を可能とする可能性を秘めるe-RNA干渉を応用した害虫防除法の確立のために必須のデータある。

Research Products

• [Presentation] RNA干渉による害虫防除は有効か？ (2019)
  • Author(s): 宮田恵多、小澤壮太、長谷川浩一
  • Organizer: 日本農芸化学会2019年度大会
• [Presentation] RNA干渉を応用した害虫防除システムの検討 (2018)
  • Author(s): 宮田恵多、小澤壮太、長谷川浩一
  • Organizer: 第34回日本ペストロジー学会
• [Book] 昆虫と自然 (2019)
  • Author(s): 宮田恵多、小澤壮太、長谷川浩一
  • Total Pages: 5
  • Publisher: ニューサイエンス社