| Project/Area Number |
17570024
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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 | Miyagi Gakuin Women's University |
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Principal Investigator |
TANAKA Kazuhiro Miyagi Gakuin Women's University, General Education, Professor, 学芸学部, 教授 (00316415)
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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 |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Ice nucleator / Isopoda / Spider / Supercooling point / Food chain / Heat susceptibility / Gut nucleator / Ice nucleating active microorganism / オオヒメグモ / 季節性 / 地理的分布 / 低温生物学 |
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| Research Abstract |
As the first step to identify the exgenous ice nucleators of the house spider, Achaearanea tepidaroirum, location of ice nucleators in the body of prey animals (Porcellio scaber) and its heat susceptibility were examined. Ingestion of the isopod's gut elevated the spider's supercooling point from -5 to -9C and this effect was comparable to that of whole body of the prey. This means that the ice nucleators exist at least in the alimentary canal of the prey animals, thus suggesting that the prey animals incorporate them in the process of feeding. Spiders that fed on a heated isopod's gut had a lower supercooling point than those fed on an unheated gut. Thus, the ice nucleators transmitting from prey to predator were susceptible to heat, thus suggesting that it is organic in origin.
To characterize the ice nucleators, their seasonal and geographical abundance in the field was examined. I found that the ice nucleators occur whole the year round and wide geographical range from northern to southern Japan. Almost all field-collected prey animals such as cricket, ants and isopods contain them. These observatons strongly suggest that the ice nucleators transmitting from prey to predator are common in the field. Because of the ubiquity, ice nucleating active microorganism such as bacteria can be the candicates as the ice nucleator.
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