2007 Fiscal Year Final Research Report Summary
| Project/Area Number |
17208016
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | Hokkaido University |
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Principal Investigator |
YAMAUCHI Kohei Hokkaido University, Faculty of Fish. Sci., Specially appointed Pro. (10109514)
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| Co-Investigator(Kenkyū-buntansha) |
ADACHI Shinji Hokkaido Univ., Faculty of Fish. Sci., Pro. (40231930)
TODO Takashi Hokkaido Univ., Faculty of Fish. Sci., Asso. Pro. (60303111)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Japanese eel / steroidogenic enzyme / lipidation / VLDL / androgen / progestin receptor / egg quality / oogenesis |
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| Research Abstract |
In this study, the controls of reproduction-related molecules were examined during ovarian development induced by repeated injections of salmon pituitary extract in the Japanese eel, Anguilla japonica. We characterized polyclonal antisera of steroidogenic enzymes including 11β-hydroxylase to analyze the mechanism of previtellogenic oocyte growth. In the next, we examined the effects of very low density lipoprotein (VLDL) and 11-ketotestosterone (11KT), a major androgen in some teleosts, on the accumulation of oil droplets into previtellogenic oocytes using ovarian culture system. Accumulation of oil droplets in previtellogenic oocytes could be induced in vitro. Co-treatment with VLDL and 11KT resulted in significant oil droplet accumulation. These data suggest that lipids in oil droplets originate, at least in part, from VLDL, and that 11KT plays an important role in their transfer and/or accumulation into oocytes. In general, oocyte maturation is induced by the maturation-inducing steroid (MIS) through the specific receptor (MIS-R). Nuclear progestin receptor (PR) or membrane-bound progestin receptor (mPR) may have the function as MIS-R. We examined the expression and localization of various types of PR and mPR during ovarian development in the Japanese eel. However, we could not identify these PR or mPR as MIS-R. In addition, we examined the causes for the deterioration in egg quality in Japanese eel and indicated that various factors involved in the process.
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Research Products
(82 results)
