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NCBI Summary:
Predicted to enable G protein-coupled receptor activity and peptide binding activity. Predicted to be involved in G protein-coupled receptor signaling pathway. Located in cilium. [provided by Alliance of Genome Resources, Nov 2021]
General function
Receptor
Comment
Cellular localization
Plasma membrane
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Ovarian function
Steroid metabolism
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Effects of gonadotropin-inhibitory hormone on folliculogenesis and steroidogenesis of cyclic mice. Singh P et al. OBJECTIVE: To evaluate the effects of gonadotropin-inhibitory hormone (GnIH) treatment on ovarian activity of mice. DESIGN: Animal study. SETTING: Reproductive physiology laboratory of university department of zoology. ANIMAL(S): Twelve-week-old female mice of inbred Parkes strain. INTERVENTION(S): Mice treated with different doses of GnIH (control, 100 ng, 500 ng, and 2 mug per day) for 8 days were studied. For in vitro study, the ovaries of proestrus mice were cultured with different doses of GnIH for 24 hours at 37 degrees C. MAIN OUTCOME MEASURE(S): Folliculogenesis, steroidogenesis, luteogenesis, and apoptosis in the ovaries of control and GnIH-treated mice. RESULT(S): GnIH treatment produced significant changes in body mass, circulating steroid levels, and ovarian activity in the mice. GnIH also caused dose-dependent histologic changes in follicular development and luteinization. The antral follicles showed abnormal changes. The mice treated with increasing dose of GnIH showed significant changes in steroid synthesis owing to inhibitory effects of GnIH on ovarian expression of LH receptor, steroidogenic acute regulatory, and 3beta-hydroxysteroid dehydrogenase proteins. CONCLUSION(S): GnIH inhibited follicular development and steroidogenesis in the ovary of mice. This study thus suggests biologic significance of this neuropeptide in regulating ovarian activity.
Expression regulated by
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Ovarian localization
Granulosa
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Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system. Bentley GE et al. Many hormones that are classified as neuropeptides are synthesized in vertebrate gonads in addition to the brain. Receptors for these hormones are also expressed in gonadal tissue; thus there is potential for a highly localized autocrine or paracrine effect of these hormones on a variety of gonadal functions. In the present study we focused on gonadotropin-inhibitory hormone (GnIH), a neuropeptide that was first discovered in the hypothalamus of birds. We present different lines of evidence for the synthesis of GnIH and its receptor in the avian reproductive system including gonads and accessory reproductive organs by studies on two orders of birds: Passeriformes and Galliformes. Binding sites for GnIH were initially identified via in vivo and in vitro receptor fluorography, and were localized in ovarian granulosa cells along with the interstitial layer and seminiferous tubules of the testis. Furthermore, species-specific primers produced clear PCR products of GnIH and GnIH receptor (GnIH-R) in songbird and quail gonadal and other reproductive tissues, such as oviduct, epididymis and vas deferens. Sequencing of the PCR products confirmed their identities. Immunocytochemistry detected GnIH peptide in ovarian thecal and granulosa cells, testicular interstitial cells and germ cells and pseudostratified columnar epithelial cells in the epididymis. In situ hybridization of GnIH-R mRNA in testes produced a strong reaction product which was localized to the germ cells and interstitium. In the epididymis, the product was also localized in the pseudostratified columnar epithelial cells. In sum, these results indicate that the avian reproductive system has the capability to synthesize and bind GnIH in several tissues. The distribution of GnIH and its receptor suggest a potential for autocrine/paracrine regulation of gonadal steroid production and germ cell differentiation and maturation.