Genome evolution and diversification of obligate symbiotic bacteria in insects: tracking survey of field populations

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K22458
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Hosokawa Takahiro 九州大学, 理学研究院, 准教授 (80722206)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 必須共生細菌の種内多型 / カメムシ / 共生細菌の置換 / 南西諸島 / ゲノム縮小 / 野外集団

Outline of Final Research Achievements

There are still few examples of field observations of the evolution of organisms. This study focused on the replacement and genome reduction of symbiotic bacteria in insects to observe the evolutionary process in field populations. A large-scale survey of symbiont infection frequencies was conducted in the past (2008-2010) in southwestern island populations of the pentatomid stinkbug Plautia stali, and comparable data were obtained in this study (2019-2021). As expected, the number of individuals with symbiotic bacteria B decreased, suggesting that symbiont replacement may be underway, but further surveys are needed to monitor the trend. I also obtained genomic samples of symbiotic bacteria to compare in future surveys.

Free Research Field

進化生物学

Academic Significance and Societal Importance of the Research Achievements

昆虫類の共生細菌の研究は実験室内における遺伝子レベルの研究に偏っており、野外で起きていることを対象にした研究は世界的に見ても稀であることから、昆虫の野外集団で共生細菌進化を調べた本研究の成果は極めてオリジナリティーの高く、注目を集めるものである。また、日本の南西諸島において非常にユニークな現象が起きていることを明らかにした点で、我が国の誇る南西諸島の生物多様性とその重要性をあらためてアピールする研究成果でもある。