title: Sexual dimorphism of steroidogenesis regulated by GnIH in the goldfish, Carassius auratus.
abstract: Gonadotropin-inhibitory hormone (GnIH) has been shown to inhibit reproduction in several species. GnIH suppresses gonadotropin synthesis/release at the hypothalamic and pituitary levels; however, increasing evidence suggests that GnIH has a putative function in the gonad. In this study, we demonstrated that GnIH receptors localize to the ovary and testis in goldfish. In situ hybridization illustrated that goldfish GnIHRs were localized exclusively to the oocytes before the cortical alveolus stage and to the interstitial tissue to the testis. Implantation of goldfish GnIH peptides did not affect the serum estradiol levels in female goldfish, but it did enhance the serum testosterone levels in males. Conversely, injecting goldfish GnIH peptides increased the expression of StAR and 3bHSD mRNA and decreased the expression of CYP19 mRNA significantly in the testis, but these genes remained unchanged in the ovary. In addition, goldfish GnIH peptides not only increased the expression of StAR and 3bHSD and decreased CYP19 mRNA, but they also increased the expression of FSHR and LHR mRNA in testicular cells. However, they did not affect the expression of these genes in ovarian cells in vitro. Thus, we suggest that GnIH may contribute to the sexual dimorphism of steroidogenesis in goldfish.
authors: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, China.
authors: Xin
authors: X
authors: Qi
authors: Wenyi
authors: W
authors: Zhou
authors: Danqi
authors: D
authors: Lu
authors: Qingqing
authors: Q
authors: Wang
authors: Huixian
authors: H
authors: Zhang
authors: Shuisheng
authors: S
authors: Li
authors: Xiaochun
authors: X
authors: Liu
authors: Yong
authors: Y
authors: Zhang
authors: Haoran
authors: H
authors: Lin
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D005260:Female; D006054:Goldfish / Q000235:genetics / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D006727:Hormone Antagonists / Q000494:pharmacology; D007028:Hypothalamic Hormones / Q000494:pharmacology / Q000502:physiology*; D017403:In Situ Hybridization; D008297:Male; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D011974:Receptors, LH / Q000235:genetics / Q000378:metabolism; D012727:Sex Characteristics; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D012739:Gonadal Steroid Hormones; D006727:Hormone Antagonists; D007028:Hypothalamic Hormones; D010750:Phosphoproteins; D011956:Receptors, Cell Surface; D011962:Receptors, FSH; D011974:Receptors, LH; D000098682:Steroidogenic Acute Regulatory Protein; D001141:Aromatase