| Project/Area Number |
17H04606
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Biodiversity/Systematics
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
Nikaido Masato 東京工業大学, 生命理工学院, 准教授 (70432010)
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| Co-Investigator(Kenkyū-buntansha) |
佐々木 剛 東京農業大学, 農学部, 教授 (00581844)
高橋 鉄美 兵庫県立大学, 自然・環境科学研究所, 教授 (70432359)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000)
Fiscal Year 2019: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2018: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
Fiscal Year 2017: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000)
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| Keywords | シクリッド / 適応放散 / ゲノム比較 / 平行進化 / 集団遺伝 / 野外調査 / ビクトリア湖 / 東アフリカ / 全ゲノム比較 / ゲノム多様性 |
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| Outline of Final Research Achievements |
We proposed and examined the hypothesis that the adaptive radiation and parallel evolution of cichlids of Lake Victoria, was achieved through natural selection on alleles derived from standing genetic variation (SGV). During a total of three field surveys, we collected about 500 cichlid specimens for 40 species of Lake Victoria and Lake Tanganyika, some of which were used for whole genome analysis. We performed whole genome wide population genetic analyses on 18 cichlids (six individuals for three species each) by focusing on Dxy and Fst. As a result, we succeeded in isolating highly differentiated genes among Lake Victoria cichlid species, and found that many of them are derived from SGV. This study strongly suggests that a substantial number of SGV-derived genes are involved in the speciation and adaptation of cichlids.
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| Academic Significance and Societal Importance of the Research Achievements |
適応進化や平行進化のメカニズムについては、自然選択による斬新的なステップの積み重ねによって進化が達成されるとする既存のダーウィン進化論のみでの説明は難しく、それに加えて新たな進化理論による説明が必要であった。本研究は、祖先状態において存在する多型に自然選択が働くことで適応放散が達成される可能性を示した。このことは1800年代から続く進化論争に新しい概念を生み出すものであり、現在の地球上における生物多様性の理解にも大きな貢献をするものと考えており、その学術的・社会的な意義は大きいと考えられる。
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