title: Expression and localization of gonadotropic hormone subunits (Gpa, Fshb, and Lhb) in the pituitary during gonadal differentiation in medaka.
abstract: To clarify the appearance of and chronological changes in two different gonadotropic hormone (Gth) cells, we examined the dynamics of Gth cells in detail during gonadal differentiation and development in the d-rR strain of medaka (Oryzias latipes). Expression of the sex-determining gene Dmy was evident in gonadal somatic cells at 5 days post-fertilization (dpf). Glycoprotein-α (Gpa)-positive cells first appeared in the pituitary at 4 dpf, regardless of genetic sex, while follicle-stimulating hormone-β (Fshb)-positive cells was detected in XX and XY embryos at 5 and 6 dpf, respectively. In contrast, luteinizing hormone-β (Lhb)-positive cells were observed in both sexes of medaka after 70 days post-hatching (dph). The density of Fshb-positive cells in the pituitary was significantly and transiently higher in XX than in XY fry at 0 dph, and thereafter no significant differences were detected before sexual maturation. In this study, temporal expression of Fshb was observed, indicating that Fsh cells become differentiated before hatching and that sexual dimorphism in Fsh cells occurs transiently after sex determination in medaka.
authors.affiliation: Laboratory of Molecular Reproductive Biology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Horie
authors.affiliation: Research Center for Aquatic Genomes, National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Shimizu
authors.affiliation: Division of Marine Life Sciences, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Adachi
authors.affiliation: Laboratory of Molecular Reproductive Biology, Institute for Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; Laboratory of Molecular Reproductive Biology, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan. Electronic address: tohruk@u-shizuoka-ken.ac.jp.
authors.forename: Tohru
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D005260:Female; D037201:Follicle Stimulating Hormone, beta Subunit / Q000378:metabolism*; D015292:Glycoprotein Hormones, alpha Subunit / Q000378:metabolism*; D006066:Gonads / Q000196:embryology*; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D037101:Luteinizing Hormone, beta Subunit / Q000378:metabolism*; D008297:Male; D009990:Oryzias; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D012733:Sex Differentiation / Q000502:physiology; D012741:Sexual Maturation
chemical_list: D037201:Follicle Stimulating Hormone, beta Subunit; D015292:Glycoprotein Hormones, alpha Subunit; D037101:Luteinizing Hormone, beta Subunit
keywords: Differentiation; Gth; Medaka; Pituitary