| Project/Area Number |
16K07520
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | Ehime University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | 共生の進化 / 実験進化 / 藻類 / 大腸菌 / 原生動物 / 共生 / 生態系 / ゲノム / 全ゲノム / 適応放散 / 進化 / マイクロコズム / 細菌 / 全ゲノム解析 / 微生物 |
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| Outline of Final Research Achievements |
Living systems evolve in ecosystems, not in isolation. Before the present research, we synthesized an experimental ecosystem in a flask using three microbial species (an alga, E. coli, a protozoan), and cultivated them for ca. 13 years, in order to understand a possible mechanism of the evolution of component species under the restriction of matter/energy flow in an ecosystem. A previous research suggested that a primary stage of symbiotic associations between the alga and E. coli, and between the alga and the protozoan evolved in this long-term culture. In the present study, using algal and E. coli isolates obtained from 6, 8, 12-year cultures, we investigated their physiological and morphological traits, ecological interactions between them, and the whole-genome DNA sequences of E. coli isolates. The results indicated that the two species evolved some symbiotic associations, and that a variety of different genetic types coexisted in the experimental ecosystem.
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| Academic Significance and Societal Importance of the Research Achievements |
微生物を用いて実験個体群や群集を作り，それを長期に培養し進化過程を明らかにする手法（実験進化）がある．しかし，従来の方法は着目する個体群のみを培養系に入れ，外部から資源を供給する形で行われてきた．本研究では，光照射のみで構成種が維持される自律型のモデル生態系を独自に開発した．これは，生態系から生物種を切り出さずに，生態系における生物進化を解析する全く新しい手法である．この培養系を13年間という長期に培養し，共生の進化の共存の仕組みを明らかにした．自然生態系は生物が互いに相互作用して進化した結果できた系あることから，本成果は，生物の共存の仕組みを進化の視点から理解することに大きく寄与する．
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