2020 Fiscal Year Final Research Report
Population genomics of medaka: analysis of selection pressures in the wild
Project/Area Number |
19K16232
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Research Category |
Grant-in-Aid for Early-Career Scientists
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Allocation Type | Multi-year Fund |
Review Section |
Basic Section 45040:Ecology and environment-related
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Research Institution | University of the Ryukyus |
Principal Investigator |
Fujimoto Shingo 琉球大学, 医学(系)研究科(研究院), 特命研究員 (60795102)
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Project Period (FY) |
2019-04-01 – 2021-03-31
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Keywords | 生活史適応 / 季節性 / 緯度間変異 / 自然淘汰 / メダカ / 集団遺伝解析 / ゲノムスキャン / 量的形質 |
Outline of Final Research Achievements |
In the wild medaka population, the reproductive seasonality changes along the latitude, and the population at high-latitude tend to be a shorter time of the reproductive season. The demographic changes may be achieved by adaptive evolution in life histories, such as growth and reproduction. We reported the reproductive pattern of the wild medaka population distributed in the Aomori where is near the northern limit of their distribution. In order to explore the genetic basis for inter-population variation in the life history of medaka populations, we analyzed the quantitative trait loci in F2 individuals crossed from wild individuals in Okinawa and Aomori. Whole-genome re-sequence were also performed on 6 populations at different latitudes. To detect footprints of natural selection, Fst and Tajima's D were calculated by performing genome scans at 50000 bp intervals.
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Free Research Field |
行動生態学、進化生態学
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Academic Significance and Societal Importance of the Research Achievements |
野生動物における生活史の適応進化は主に表現型変異に基づいて研究されてきた。近年、ゲノムワイドな遺伝的変異の検出が容易になったことで分子メカニズムも検討できるようになりつつある。メダカ科魚類は熱帯に分布する近縁種を含めたゲノム解読を日本の研究チームが精力的に進めているため、日本のメダカは生活史の適応進化とその遺伝基盤を検証する有効な系である。しかしながら、野外での適応進化を議論するのに必要な野生集団の核ゲノムの対立遺伝子頻度に関する知見が限られることに課題があった。本研究で得られた野生集団の遺伝子変異カタログは生活史に限らず、野外での魚類の適応進化を研究する上で有効な基礎的知見になるだろう。
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