title: Follicle-stimulating hormone induces spermatogenesis mediated by androgen production in Japanese eel, Anguilla japonica.
abstract: Follicle-stimulating hormone (FSH) plays important roles in spermatogenesis. However, the biologic activity of FSH can vary in different vertebrate classes, and the definitive function of FSH has not been established. In this study, we investigated the functions of FSH on spermatogenesis using an in vitro culture system for Japanese eel testis. The eel Fsh receptor was expressed in testis tissue during the whole process of spermatogenesis, mainly by Leydig cells that produce steroid hormones and by Sertoli cells surrounding type A spermatogonia and early type B spermatogonia. In an in vitro organ culture, recombinant eel Fsh (r-eFsh) induced complete spermatogenesis from the proliferation of spermatogonia to spermiogenesis during 36 days of culture; also, spermatozoa were observed in the testicular fragments. Spermatogenesis induced by r-eFsh was inhibited by trilostane, a specific inhibitor of 3beta-hydroxysteroid dehydrogenase. However, trilostane did not inhibit spermatogenesis induced by 11-ketotestosterone. These results clearly show that the main function of FSH in eel is to induce spermatogenesis via stimulating androgen production.
authors.affiliation: Laboratory of Fish Reproductive Physiology, Ehime University, Ehime 790-8566, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohta
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Miyake
authors.forename: Chiemi
authors.initials: C
authors.lastname: Miura
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kamei
authors.forename: Katsumi
authors.initials: K
authors.lastname: Aida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miura
mesh_terms: D000595:Amino Acid Sequence; D000728:Androgens / Q000096:biosynthesis*; D000811:Anguilla; D000818:Animals; D006063:Chorionic Gonadotropin; D013196:Dihydrotestosterone / Q000031:analogs & derivatives; D005640:Follicle Stimulating Hormone / Q000502:physiology*; D012739:Gonadal Steroid Hormones / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D008297:Male; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D011962:Receptors, FSH / Q000737:chemistry / Q000378:metabolism*; D012102:Reproductive Control Agents; D017422:Sequence Analysis, DNA; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000378:metabolism* / Q000502:physiology
chemical_list: D000728:Androgens; D006063:Chorionic Gonadotropin; D012739:Gonadal Steroid Hormones; D011962:Receptors, FSH; D012102:Reproductive Control Agents; D013196:Dihydrotestosterone; D005640:Follicle Stimulating Hormone; C009954:trilostane