| Project/Area Number |
16570025
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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 | Tokyo University of Marine Science and Technology (2006)
Natural History Museum and Institute, Chiba (2004-2005) |
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Principal Investigator |
SUNOBE Tomoki Field Science Centor, Associate professor, 水圏科学フィールド教育研究センター, 助教授 (00250142)
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| Co-Investigator(Kenkyū-buntansha) |
KAWASE Hiroshi Natural History Museum and Institute, Chiba, Coastal Museum, Curator, 分館・海の博物館, 研究員 (10270620)
SAKURAI Makoto Kagoshima Immaculate Heart College, Science of Living Department, Associate Professor, 生活学科, 助教授 (90321356)
SHINOMIYA Akihiko Kagoshima University, Faculty of Fisheries, Professor, 水産学部, 教授 (90041722)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Sex change / Hermaphrodite / Social structure / Mating system / Stroid hormone / Aromatase / Gobiidae / Trimma / 免疫組織化学 |
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| Research Abstract |
In this project, there are three main results as follows.
1.Mating system of the gobiid fish Trimma okinawae is harem polygyny, which the largest individual controls females within a social guoup as a male. In the wild condition, 22 and 3 cases of female to male and male to female sex change were observed, respectively. The females changed to male by disappearance of the males in the former case. As the males became solitary, they immigrated to the other groups as female. The females sometimes moved to the other groups. In these cases, their social rank promoted before movement.
2.Gonadal structure of 10 species of Trimma and closely related 4 Priolepis and 2 Trimmatom species were histologically investigated. All species of Trimma and Priolepis had simultaneously ovary and testis like T. okinawae, showing that these genera exhibit bi-directional sex change. The female and male of Trimmatom had only ovary and tesis, respectively, suggesting that this genus is gonochoristic.
3.Endcrinological aspects of sex change in T. okinawae were clarified by immunohistochemical methods for 3 steroid producing enzymes P450scc, 36-HSD and Arom. Our results show that Arom was important for sex change. The expression of Ad4BP/SF-1 was investigated throughout sex change, which increased by onset of the female phase and decreased as becoming male. Ad4BP/SF-1 may be an important indirect regulator of oocyte growth.
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