Establishment of coral symbiotic algae transformation technology and functional analysis of symbiosis-related genes

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15871
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Kyoto University (2022-2023); Miyagi University of Education (2020-2021)
• Principal Investigator: Ishii Yuu 京都大学, 農学研究科, 特別研究員(RPD) (40770813)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 褐虫藻 / 細胞内共生 / 進化 / 遺伝子導入 / サンゴ

Outline of Final Research Achievements

Symbiodiniaceae, unicellular algae, construct endosymbiosis with corals and other cnidarians, and this symbiotic relationship changes with environmental changes. To understand the molecular mechanisms of this symbiotic relationship, the lack of established genetic engineering techniques for Symbiodiniaceae is a barrier to analysis. In this study, I aimed to establish a highly reproducible gene transformation method for Symbiodiniaceae, search for candidate genes involved in symbiosis, and analyze their molecular functions. In examining the gene transfer method, I determined the conditions for high transfer efficiency by the gene transfer equipment, NEPA. The search for candidate genes involved in symbiosis and functional analysis suggested that starch synthase was involved in the evolution of symbiosis, and that changes in the localization of starch synthase in cytoplasm might have been involved in the evolution of symbiosis.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

本研究では、熱帯・亜熱帯海域の生態系を一次生産者として支える、刺胞動物と褐虫藻の細胞内共生の分子メカニズム解明のために必要な、褐虫藻の再現性の高い遺伝子導入法開発を大きく前進させることができた。さらに、共生に関わる候補遺伝子を特定し、その機能を推定できたことから、刺胞動物と褐虫藻の共生関係がどの様に進化してきたのかを明らかにする手がかりが得られた。これらのことは、地球温暖化や海洋酸性化といった環境問題に対して、共生の崩壊（いわゆるサンゴの白化現象）にどの様に対処することができるか、といった応用研究の基盤となることが期待される。