title: Development of approaches to induce puberty in cultured female sablefish (Anoplopoma fimbria).
abstract: Efforts to establish sustainable and efficient aquaculture production of sablefish (Anoplopoma fimbria) have been constrained by delayed puberty in cultured females. This study integrates a series of experiments aimed at gaining an understanding of the reproductive physiology of puberty in female sablefish. We detected transcripts for the dopamine D2 receptor (drd2) in brain, pituitary and ovary of sablefish, and prepubertal females exhibited significantly elevated brain and pituitary drd2 expression relative to wild maturing females. Treatments with sustained-release cholesterol pellets containing testosterone (T) and the dopamine D2 receptor antagonist, metoclopramide (Met), stimulated expression of pituitary luteinizing hormone beta subunit (lhb) and follicle-stimulating hormone beta subunit (fshb), respectively, in prepubertal females, whereas a combination of T and gonadotropin-releasing hormone agonist (GnRHa) had a strong synergistic effect on lhb expression (2000-fold higher than control). Although T induced a significant increase in the maximum ovarian follicle volume, none of the treatments tested stimulated onset of vitellogenesis. Using liquid chromatography/tandem mass spectrometry, we demonstrated that Met stimulated production of T by previtellogenic ovarian follicles in vitro, whereas gonadotropin preparations enhanced 17α-hydroxyprogesterone, androstenedione (A4), T and 17β-estradiol (E2) production. Treatment with T increased production of A4, 11β-hydroxyandrostenedione, 11β-hydroxytestosterone, E2, 11-ketotestosterone, and 5α-dihydrotestosterone (DHT). Interestingly, in the presence of high doses of T the previtellogenic ovary preferentially produced A4 and DHT over any other metabolite. Our data suggest the existence of dopamine inhibition of the reproductive axis in female sablefish. Treatments with Met and T elevated gonadotropin mRNAs in prepubertal females but failed to stimulate the transition into vitellogenic growth, suggesting a possible failure in pituitary gonadotropin protein synthesis/release. Previtellogenic ovarian follicles of sablefish are equipped to synthesize steroids, including those required for vitellogenic growth, and DHT, a steroid hormone whose role in reproduction of fishes remains unknown.
authors.affiliation: Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration - National Marine Fisheries Service, Seattle, WA 98112, USA. Electronic address: jose.guzman-jimenez@noaa.gov.
authors.forename: José M
authors.initials: JM
authors.lastname: Guzmán
authors.affiliation: Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration - National Marine Fisheries Service, Seattle, WA 98112, USA; Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA.
authors.forename: J Adam
authors.initials: JA
authors.lastname: Luckenbach
authors.affiliation: Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration - National Marine Fisheries Service, Seattle, WA 98112, USA.
authors.forename: Denis A M
authors.initials: DA
authors.lastname: da Silva
authors.affiliation: Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration - National Marine Fisheries Service, Seattle, WA 98112, USA.
authors.forename: Gina M
authors.initials: GM
authors.lastname: Ylitalo
authors.affiliation: Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration - National Marine Fisheries Service, Seattle, WA 98112, USA; Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA.
authors.forename: Penny
authors.initials: P
authors.lastname: Swanson
mesh_terms: D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism; D065127:Dopamine D2 Receptor Antagonists / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005399:Fishes / Q000254:growth & development* / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D006062:Gonadotropins / Q000378:metabolism*; D008787:Metoclopramide / Q000494:pharmacology*; D010053:Ovary / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011627:Puberty / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012098:Reproduction / Q000187:drug effects / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012741:Sexual Maturation / Q000187:drug effects / Q000502:physiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D065127:Dopamine D2 Receptor Antagonists; D006062:Gonadotropins; D012333:RNA, Messenger; D013196:Dihydrotestosterone; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; C003600:11-ketotestosterone; D008787:Metoclopramide
keywords: Androgens; DHT; Dopamine; GnRHa; Gonadotropins; Puberty