Elucidation of recombinant eel gonadotropin actions for the improvement of artificial maturation methods in male eels

Research Project

Project/Area Number	17K07952
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Aquatic life science
Research Institution	Fisheries Research and Education Agency
Principal Investigator	Ozaki Yuichi 国立研究開発法人水産研究・教育機構, 増養殖研究所, 主任研究員 (10734030)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000) Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	精子形成 / ニホンウナギ / 濾胞刺激ホルモン / 黄体形成ホルモン / セルトリ細胞 / ライディッヒ細胞 / 輸精管 / ステロイドホルモン / 11-ケトテストステロン / 精原細胞 / 精母細胞 / 水産学 / 生理学
Outline of Final Research Achievements	We examined mechanisms of recombinant Japanese eel follicle-stimulating hormone and luteinizing hormone (reFsh and reLh) actions for the improvement of artificial maturation methods in male eels. It was appeared that reLh induced 11-ketotestosteron production and subsequent spermatogenesis more rapidly compared with reFsh through the up-regulation of 11β-hydroxylase and 11β-hydroxysteroid dehydrogenase type 2 expressions in Leydig cells. In vitro experiments showed that eel sperm ducts had a potential to produce 17α, 20β-dehydroxy-4-pregnen-3-one. Additionally, it was showed that potassium ions in seminal plasma were essential for the sperm motility.
Academic Significance and Societal Importance of the Research Achievements	本研究により、組換えニホンウナギ濾胞刺激ホルモン（reFsh）および黄体形成ホルモン（reLh）の成熟への作用機構の詳細、特にその差異の一部が明らかになった。今後、これらの結果をもとに、reFshおよびreLhを用いたニホンウナギ催熟技術の高度化が確実に進み、さらには産業規模でのニホンウナギ人工種苗生産技術の確立にも繋がると考えられる。また、魚類では明確になっていないFshおよびLhの作用の違いを明らかにしたことは学術的にも意義は大きい。