title: Androgen-specific regulation of FSH signalling in the previtellogenic ovary and pituitary of the New Zealand shortfinned eel, Anguilla australis.
abstract: The evidence for androgens having a pivotal role in the functioning of the female reproductive axis--such as initiating puberty or vitellogenesis--is mounting. However, the use of aromatizable androgens and the tissue-specific focus of most studies often make it unclear if androgenic effects throughout the axis proceed via androgen or estrogen signalling mechanisms. In this study, we assessed the effects of 11-ketotestosterone (11KT, a non-aromatizable androgen) on the pituitary and ovary of previtellogenic (PV) freshwater eels Anguilla australis, comparing them with eels naturally undergoing early vitellogenesis (EV). We found that 11KT treatment produces molecular and morpho-physiological phenotypes that were generally intermediate between PV and EV. Most notably, we demonstrated that 11KT induces effects on follicle-stimulating hormone (FSH) signalling in the pituitary and ovaries that are in opposition to each other. Thus, 11KT significantly reduced fshβ subunit expression in the pituitary. At the same time, 11KT dramatically increased mRNA levels of ovarian FSH receptor and plasma levels of estradiol-17β, very likely sensitizing the previtellogenic follicle to the FSH signal. Androgens therefore may be important in facilitating puberty in the eel.
authors.affiliation: Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9016, New Zealand. alvin.setiawan@otago.ac.nz
authors.forename: Alvin N
authors.initials: AN
authors.lastname: Setiawan
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Alireza
authors.initials: A
authors.lastname: Shoae
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Kazeto
authors.forename: P Mark
authors.initials: PM
authors.lastname: Lokman
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000811:Anguilla; D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D009520:New Zealand; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism*; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism*; D011962:Receptors, FSH / Q000235:genetics; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000728:Androgens; D011962:Receptors, FSH; D013739:Testosterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; C003600:11-ketotestosterone