Involvement of nutritive cord in the stage specific regulation of telotrophic ovary

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06072
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39050:Insect science-related
• Research Institution: Kyoto Institute of Technology
• Principal Investigator: Takaki Keiko 京都工芸繊維大学, 応用生物学系, 准教授 (30401938)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 単栄養型卵巣

Outline of Final Research Achievements

We have tried RNAi against candidate molecules involved in the transportation from nurse cells to oocyte via nutritive cord. Most candidates did not show specific phenotype, except Kinesin-1. The RNAi against Kinesin-1 induced abnormal double layered follicle at vitellogenic stage. The details of the phenotype of Kinesin-1 RNAi was published in the Journal of Insect Biotechnology and Sericology and presented in the meeting of The Japanese Society of Sericultural Science.
Vitellogenic stage specific follicle death induced by starvation is supposed to be regulated by nurse cells nutritive cord. In order to test the hypothesis, we analyzed the details of the follicle cells. We observed insulin signaling and nuclear phase of somatic follicle cells play inportant roles in the follicle death, but they did not seem to be involved in the transportation of nutritive cord. We reported those results in the conference of The Molecular Biology Society of Japan.

Free Research Field

昆虫生理

Academic Significance and Societal Importance of the Research Achievements

端栄養型卵巣に関する分子生物学的研究は非常に少ない。特に、生殖細胞の構造などが大きく異なる多栄養型卵巣と端栄養型卵巣の比較は、生殖細胞が将来個体となる卵と、卵をケアする保育細胞と役割を分担するように進化した過程や意義を探るうえで、学術的に重要であると考える。本研究では、物質輸送に関わるキネシンのノックダウンが、卵黄合成期初期特異的に異常を誘導することが明らかとなった。この時期は多栄養型卵巣でも特異的な細胞死が確認される時期であることから、この時期の濾胞特異的な進化的に保存された機構を示唆するものと考えている。生殖に関わる知見は、害虫防除や保全のための新しい技術開発の一助になると考えている。