2019 Fiscal Year Final Research Report
Experimental reproduction of ecological speciation caused by inter-specific hybridization and elucidation of its genetic mechanism
Project/Area Number |
16H06178
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Research Category |
Grant-in-Aid for Young Scientists (A)
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Allocation Type | Single-year Grants |
Research Field |
Biodiversity/Systematics
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Research Institution | Kyushu University |
Principal Investigator |
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Project Period (FY) |
2016-04-01 – 2019-03-31
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Keywords | 雑種種分化 / 生態的種分化 / 寄主特異性 / エコゲノミクス |
Outline of Final Research Achievements |
In Japanese phytophagous ladybird beetles, we certified that a population of the blue cohosh specialist species in Southern Hokkaido is formed as homoploid hybrid speciation caused by hybridization between closely related thistle specialist species and generalist of blue cohosh and thistle in Hokkaido. The blue cohosh specialist species, which has been thought to be a single species has evolved independently multiple times throughout Japan archipelago. Artificial F1 hybrid offspring of the two parental species in Hokkaido could accept both parental host plants, while they demonstrated significantly reduced larval survivorships on thistle. These results indicate that the blue cohosh specialist species in Southern Hokkaido evolves avoidance against unfit thistle plant after hybridization.
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Free Research Field |
種分化
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Academic Significance and Societal Importance of the Research Achievements |
今回、種間交雑が(1) F1以降の食性幅を変え、その後 (2)特定の食草への特殊化が進む、という2段階の過程を経て種分化が起きることが示唆された。これまで雑種種分化はF1あるいはF2における超越分離で生殖隔離が生じるとされてきたが、交雑の時点(1)では大きな生殖隔離の成立には至らず、その後の選択によって生殖隔離ができていることになる。 北海道南部のルイヨウマダラテントウが本州の同種とは独立起源のものであることが示されたことで、分類学的な同一種の中に異なる遺伝的・進化的背景を持った個体群が存在することが明らかになった。これによって保全の単位の見直しを提言することが可能になる。
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