| 研究課題/領域番号 |
19F19723
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| 研究種目 |
特別研究員奨励費
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| 配分区分 | 補助金 |
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| 応募区分 | 外国 |
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| 審査区分 |
小区分45020:進化生物学関連
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| 研究機関 | 沖縄科学技術大学院大学 |
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研究代表者 |
ミケェエヴ アレクサンダー 沖縄科学技術大学院大学, 生態・進化学ユニット, 准教授 (90601162)
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| 研究分担者 |
TECHER MAEVA 沖縄科学技術大学院大学, 生態・進化学ユニット, 外国人特別研究員
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| 研究期間 (年度) |
2019-07-24 – 2021-03-31
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| 研究課題ステータス |
完了 (2020年度)
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| 配分額 *注記 |
1,200千円 (直接経費: 1,200千円)
2020年度: 200千円 (直接経費: 200千円)
2019年度: 1,000千円 (直接経費: 1,000千円)
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| キーワード | Parasite / Invasion / Coevolution / Varroa / Honey bee / Population genomics / Whole-genome sequencing / parasites / mites / viruses / honey bees / coevolution |
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| 研究開始時の研究の概要 |
As first of its kind, I plan to do population genomics of V. destructor at a global scale by sequencing the whole genome of 500 mites. The project is based on my previous results: i) the new reference V. destructor genome, ii) genomics pipeline used in Asian populations and iii) the so far largest Varroa mite world collection (< 800 samples from five continents) achieved in the proposed host Ecology and Evolution lab. I will be sequencing the whole genome of mites from native and invasive areas from all continents, different host populations and mite phenotypes.
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| 研究実績の概要 |
Since 2016, we initiated a Varroa world collection that was large of 878 samples from 31 countries. During the fellowship, we succeeded in increasing its size and coverage by developing new international collaborations with now 1659 samples from 60 countries. We unearthed i) 106 historical samples collected during V. destructor early spread between 1989 to 2000 and ii) all Varroa species, including undescribed ones. Using our reference genome of V. destructor (Vdes3.0) and state-of-the-art genomic tools, we successfully sequenced the whole genome of 1760 samples worldwide.
By focusing on the native range, where the parasites exist in sympatry on a novel and original host, we found that host switches put the parasites on the path to speciation but that each switch requires considerable genetic diversity to take hold. We were able to reconstruct the origin of host switches and pin-point new ones with congruent and independent analysis. This is in stark contrast to the long-held view that Varroa is quasi-clonal on the novel host and explains its remarkable adaptability to different host races and human countermeasures.
We then studied the world biogeography of the invasive V. destructor using spatial and temporal population genomics. We were able to show that key elements to Varroa’s success were due to unreported host switch events and multiple invasion pathways which promoted hybridization. By looking at different population levels (from host colony to continents), we further elucidate the origin and evolution of V. destructor on its new host.
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| 現在までの達成度 (段落) |
令和2年度が最終年度であるため、記入しない。
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| 今後の研究の推進方策 |
令和2年度が最終年度であるため、記入しない。
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