Elucidation of the establishment and maintenance mechanism of endosymbiosis using the ciliate Paramecium bursaria

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07513
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Evolutionary biology
• Research Institution: Shimane University
• Principal Investigator: Kodama Yuuki 島根大学, 学術研究院農生命科学系, 准教授 (80582478)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ミドリゾウリムシ / クロレラ / 細胞内共生 / 進化 / ミトコンドリア / モノクローナル抗体 / 蛍光抗体法 / 原生生物

Outline of Final Research Achievements

Endosymbiosis that created mitochondria and chloroplasts is still ongoing among many organisms, and is a driving force for eukaryotic cell evolution and diversification. However, the mechanism of establishment and maintenance of the endosymbiosis is not well known. The model organisms to elucidate these problems are the ciliate Paramecium bursaria and the symbiotic Chlorella spp. Symbiotic Chlorella sp. is localized beneath the host cell cortex by adhesion between the host mitochondria and the perialgal vacuole (i.e., symbiosome) membrane. In order to investigate the function of the host mitochondria in establishing and maintaining endosymbiosis, we produced anti-P. bursaria mitochondria monoclonal antibodies. Using the antibody, the localization of the antigens of both symbiotic algae-removed and -bearing P. bursaria strains was compared by using an indirect immunofluorescent microscopy.

Free Research Field

進化生物学

Academic Significance and Societal Importance of the Research Achievements

本研究は分子生物学的、細胞生物学的および物理学的な手法であるラマン分光法など、多岐にわたる研究手法を用いて細胞内共生の成立および維持機構を解明することを目的としており、ミドリゾウリムシとクロレラの共生系のみで可能な新規性とオリジナリティーの高い試みである。申請者らの研究は、細胞内共生の成立に普遍的な現象の解明、藻類との細胞内共生が進行中の他の生物の維持によって保証される生態系の維持と環境保全、細胞内共生による真核細胞の進化と多様性のメカニズムの解明等にも繋がると期待される。