| Project/Area Number |
17570027
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | Forestry and Forest Products Research Institute |
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Principal Investigator |
SHIMADA Takuya Forestry and Forest Products Research Institute, Tohoku Research Center, Chief Researcher, 東北支所, 主任研究員 (10353723)
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| Co-Investigator(Kenkyū-buntansha) |
OSAWA Ro Kobe University, Graduate School of Science and Technology, Professor, 自然科学研究科, 教授 (10253189)
SAITOH Takashi Hokkaido University, Field Science Center, Assistant Professor, 北方生物圏フィールド科学センター, 助教授 (00183814)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | tannin / acorn / tannin-binding protein / tannase-producing bacteria / animal-plant interaction / acclimation / defense mechanism against tannins / seed dispersal / 動物-植物相互作用 / コナラ属 / アカネズミ / タンナーゼ産生腸内細菌 |
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| Research Abstract |
Acorns (seeds of oak trees) are staple resource for forest-dwelling wildlife, but they contain high level of tannins and cause negative effects on consumers, such as injury on gastrointestinal tract and lever and kidney failure. In order to elucidate the defense mechanisms against tannins in the Japanese wood mouse Apodemus speciosus, which heavily rely on acorns during fall and winter, we investigated the role of physiological acclimation against tannins and selective foraging decreasing tannin intake.
First, we allocated 26 wood mice into two groups: the acclimated group and the non-acclimated group. Of the 14 mice in the non-acclimated group, 8 died, whereas only 1 of the 12 mice in the acclimated group died. Mean body weight change was -17.9‰ in the non-acclimated group and -2.5% in the acclimated group. Food intake, dry matter digestibility, and nitrogen digestibility were much higher in the acclimated group than in the non-acclimated group. These results indicate that wood mice can mitigate the negative effects of tannins by acclimation. Path analysis revealed that increased secretion of tannin-binding salivary proteins (TBSPs) and abundance of tannase-producing enterobacteria (TPB) may be main elements of the mechanism of acclimation to tannins.
Second, we examined the selective foraging against tannins by the wood mouse and revealed that wood mice can selectively consume acorns with low tannin content and avoid ones with high tannin content.
These findings indicate that the wood mouse can consume tannin-rich acorns effectively with these physiological and behavioral defense mechanisms against tannins.
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