| Project/Area Number |
22770019
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Ecology/Environment
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| Research Institution | Kobe University |
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Principal Investigator |
TAKAMI Yasuoki 神戸大学, 大学院・人間発達環境学研究科, 准教授 (60432358)
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| Project Period (FY) |
2010 – 2011
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| Project Status |
Completed (Fiscal Year 2011)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2011: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2010: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Keywords | 進化生態学 / エコゲノミクス / 種分化 / 生殖隔離 / 交尾器 / オサムシ / ゲノミクス / 進化 / 生態ニッチモデリング |
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| Research Abstract |
The present study aimed to determine the genomic location of genes concerning reproductive isolation(i. e., speciatin genes), and to explore their association with phenotypic traits. We used two species of carabid beetles, Carabus iwawakianus and C. maiyasanus, which belong to the subgenus Ohomopterus that posesses species-specific genital lock-and-key systems, being a model system in speciation studies.
Genome scans using genomic cline analyses in a hybrid zone revealed that natural selection operated on genomic regions linked to QTL for genital morphology. Of 12 microsatellites, 7 of 8 QTL-linked markers significantly departed from null expectation assuming genetic drift only, whereas none of 4 unlinked markers did. The shape of selection was mostly directinal to avoid the cost of genital injury due to the mismatch between the heterospecific genitalia : short and narrow male genitalia and long female receptacle were selected. These results suggest that genes responsible for species-specific genital morphologies are speciation genes concerning reproductive isolation between the two closely-related species.
Ecological niche modeling and subsequent comparison of the models using the niche identity test and background similarity test revealed that habitat preferences of those two species were differentiated even within contact areas, suggesting niche differentiation plays an additional role in maintaining narrow hybrid zones between the two species, and may be associated with their speciation.
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