2024 Fiscal Year Final Research Report
Exploring genomic signatures of Ryukyu-ayu to inform the survival of an endangered fish species
| Project/Area Number |
20K06191
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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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| Review Section |
Basic Section 40030:Aquatic bioproduction science-related
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| Research Institution | Fukui Prefectural Satoyama-Satoumi Research Institute (2024)
Fukui Prefectural University (2022-2023)
Tokai University (2020-2021) |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
安房田 智司 大阪公立大学, 大学院理学研究科, 教授 (60569002)
橋口 康之 大阪医科薬科大学, 医学部, 准教授 (70436517)
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| Project Period (FY) |
2020-04-01 – 2025-03-31
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| Keywords | 生物多様性 / 絶滅危惧種 / リュウキュウアユ / アユ / 低カバレッジ全ゲノムシーケンス / 集団ゲノミクス |
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| Outline of Final Research Achievements |
To elucidate the genetic characteristics essential for the long-term persistence of the endangered fish Ryukyu-ayu, we performed demographic inference using whole-genome resequencing and comparative population genomics using low-coverage whole-genome resequencing for the two subspecies of ayu including ayu and Ryukyu-ayu. Our analysis revealed that Ryukyu-ayu has persisted with significantly smaller effective population sizes than ayu since the Last Glacial Maximum. Despite a marked reduction in genome-wide genetic variation, Ryukyu-ayu retains a relatively high number of nonsynonymous substitutions. In addition, we identified genomic regions with elevated genetic diversity encompassing genes associated with host immune defense and mRNA surveillance pathways-key biological functions linked to organismal survival. These regions exhibited signatures of balancing selection, suggesting maintenance of adaptive variation despite prolonged small population size.
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| Free Research Field |
保全ゲノム科学
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| Academic Significance and Societal Importance of the Research Achievements |
現在，地球上では人類の活動に起因して，絶滅危惧にある生物が加速度的に増加している．第6の大量絶滅期であると言われ，絶滅危惧種の保全は世界的な緊急課題である．日本でも汽水・淡水魚類の42％が絶滅危惧種とされ，各動物分類群のなかでも最も高い割合を示す．これまで研究事例が少なかった魚類の絶滅危惧種について，リュウキュウアユという日本固有の絶滅危惧魚類をモデルとした保全ゲノミクスを実施した．本研究の成功は，日本の魚類の保全ゲノミクス分野を牽引するのは間違いないばかりか，その成果をより速く世界に発信し，汽水・淡水魚類の生物多様性・保全ゲノミクスの研究分野を「日本」が世界的にリードする基盤を構築できる．
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