Cell processes and mechanisms during horizontal transmission of symbiotic bacteria in Bathymodiolus mussels

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06799
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45020:Evolutionary biology-related
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Ikuta Tetsuro 国立研究開発法人海洋研究開発機構, 地球環境部門(海洋生物環境影響研究センター), 研究員 (80584846)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 化学合成 / 共生細菌 / シンカイヒバリガイ / 水平伝達 / 細胞形態 / 共生進化

Outline of Final Research Achievements

Symbiosis with chemosynthetic autotrophic bacteria is a biological phenomenon that has enabled animals to adapt and evolve to deep-sea environments, and the acquisition of symbiotic bacteria is a core process. In this study, we conducted various infection experiments, histological analyses, and gene expression analyses in order to elucidate what is happening in the gill cells of Bathymodiolus mussels when they take up chemosynthetic bacteria from the environment. As results, we clarified the intracellular/extracellular intermediary property of symbiosis in Bathymodiolus mussels and proposed a new evolutionary model of the Bathymodiolus symbiosis as well as a novel hypothesis for the symbiotic bacterial uptake process at the cellular level.

Free Research Field

共生生物学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果により、これまで未知であったシンカイヒバリガイ類が共生菌を環境からどのように獲得するのか？その細胞プロセスについて理解が進み、動物の深海環境への適応進化機構の理解も深まった。また本研究成果を手掛かりとして、他の生物でも蓄積されつつある水平伝達機構についての知見との比較を行うことで、細胞内共生系の成立と進化における動物門を超えた共通の機構解明へ向けた研究展開が期待できる。