Exploration of the producing site for the alkenyl sex pheromone in moth.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K18823
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Insect science
• Research Institution: The University of Tokyo (2017-2018); Tokyo University of Agriculture and Technology (2016)
• Principal Investigator: Fujii Takeshi 東京大学, 大学院農学生命科学研究科(農学部), 特任助教 (30730626)
• Research Collaborator: Inaba Hiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ガ類性フェロモン生合成経路 / 炭化水素型性フェロモン / ガ類性フェロモン交信系 / 脂肪滴 / CYP4G / エノサイト

Outline of Final Research Achievements

The unknown cell and enzymatic gene involved in decarboxylation or decarbonylation on the synthetic pathway of alkenyl sex pheromone was explored. The candidate gene, which specifically expressing in the female epidermal cells of Hyphantria cunea, was found and given name as HcCYP4G77. To demonstrate the function of the gene, recombinant was constructed by insect cell expression system. Incubation the construct with an essential fatty acid or its aldehyde form and GC-MS analysis for the extracts revealed the function is decarbonylase. Due to the weak activity of the construct, RNAi was subsequently challenged to investigate the gene function of HcCYP4G77. Down regulation with three double strands (#1-#3) designed by sequence information of HcCYP4G77 by RNAi revealed #1 only reduced pheromone level to 19.2 % .
Finally, in situ hybridization demonstrated the gene expressing cell was vicinity of the epidermis, we tentatively given the name of cell as "pheromone producing cell".

Free Research Field

昆虫生理・生化学、化学生態学

Academic Significance and Societal Importance of the Research Achievements

農業の重要害虫にガ類が多くみられる理由の一つは、メスガの出す性フェロモンが広大な空間から同種オスガを誘引し効率の良い交配の実現に加え、生殖隔離が働き交雑種の出現を抑え、多様化した種を安定して維持できるためである。本課題の成果により、これまで不明だった炭化水素型性フェロモンの生合成の場と、そこで働く酵素の遺伝子の実体が示された。この結果、既に分子レベルで概要が明らかとなっているガ類脂肪族型性フェロモンの生合成機構と比較しながら、ガ類の種分化と性フェロモンの交信系の分子進化のより深い考察が可能となった。