Molecular mechanisms underlying the cessation of JH biosynthesis in the corpora allata; Identification of the final instar-specific JHAMT inhibitory transcription factors

2021 Fiscal Year Final Research Report

• Project/Area Number: 21K20587
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0602:Agricultural and environmental biology and related fields
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: INUI Tomohiro 国立研究開発法人農業・食品産業技術総合研究機構, 生物機能利用研究部門, 契約研究員 (50911020)
• Project Period (FY): 2021-08-30 – 2022-03-31
• Keywords: 幼若ホルモン / 変態 / 脱皮 / アラタ体 / 転写因子

Outline of Final Research Achievements

In this study, we searched for genes that specifically repress the expression of JHAMT, a key juvenile hormone (JH) biosynthetic enzyme, (JHAMT Repressor, JHAMT-Rep) in the corpora allata (CA) in a final instar-specific manner. We comprehensively searched for genes whose expression is upregulated specifically in the last instar larvae by RNA-seq using total RNA extracted from CA, and created an RNAi library based on the transcriptomic data. The RNAi screening was performed using Red flour beetle, Tribolium castaneum, and the candidate genes for JHAMT-Rep were identified. RNAi knockdown of JHAMT-Rep candidate gene resulted in supernumerary larvae in T. castaneum. This result suggested that JH concentration in the body did not decrease in RNAi treated animals, and thus they could not metamorphose.

Free Research Field

昆虫生理学

Academic Significance and Societal Importance of the Research Achievements

JHの変態抑制作用は昆虫に普遍的かつ特徴的な生理作用であり、昆虫の繁栄の要因の一つであることから、学術的な興味はもとより創農薬の有望なターゲットとして注目されており、その生合成やシグナル経路の解明が急務である。本研究の成果は、前述のJHAMT-Rep候補遺伝子の同定と機能解析から、JHの生合成制御機構の解明に貢献した。