Duplicated membrane estrogen receptors in the European sea bass (Dicentrarchus labrax): Phylogeny, expression and regulation throughout the reproductive cycle. Issue 178 (April 2018)

• Record Type: Journal Article
• Authors: Pinto, Patrícia I.S.; Andrade, André R.; Estêvão, M. Dulce; Alvarado, M. Victoria; Felip, Alicia; Power, Deborah M.
• Is Part Of: Journal of steroid biochemistry and molecular biology. Issue 178(2017)
• Page Start: 234
• Page End: 242
• Publication Date: 2018-04
• Subjects: 18s 18S ribosomal RNA -- 7TM seven transmembrane domains -- aa amino acids -- CDS coding sequence -- E2 17β-estradiol -- Ef1α elongation factor 1-alpha -- Esr nuclear estrogen receptor -- Fsh follicle stimulating hormone -- GPCRs G-protein coupled receptors -- Gper G protein-coupled estrogen receptor -- Gnrh gonadotropin-releasing hormone -- GSI gonadosomatic index -- HPG axis Hypothalamus-Pituitary-Gonads axis -- Lh luteinizing hormone -- qPCR quantitative polymerase chain reaction; Brain -- Evolution -- G protein-coupled estrogen receptors -- Pituitary -- Reproduction -- Teleost; Steroid hormones -- Periodicals; Biochemistry -- Periodicals; Hormones -- Periodicals; Molecular Biology -- Periodicals; Hormones stéroïdes -- Périodiques; Steroid hormones; Periodicals; 572.579
• DOI: 10.1016/j.jsbmb.2017.12.019
• Languages: English
• ISSNs: 0960-0760

Abstract

Highlights: Teleost genomes possess duplicate membrane estrogen receptors gpera and gperb . Sea bass gpera is mainly expressed in brain and pituitary in both sexes. Gperb has a more widespread tissue distribution. Both gpers are expressed in hypothalamus and pituitary along the reproductive cycle. Gpers showed differential seasonal and tissue regulation in both male and female. Abstract: The numerous estrogen functions reported across vertebrates have been classically explained by their binding to specific transcription factors, the nuclear estrogen receptors (ERs). Rapid non-genomic estrogenic responses have also been recently identified in vertebrates including fish, which can be mediated by membrane receptors such as the G protein-coupled estrogen receptor (Gper). In this study, two genes for Gper, namely gpera and gperb, were identified in the genome of a teleost fish, the European sea bass. Phylogenetic analysis indicated they were most likely retained after the 3R teleost-specific whole genome duplication and raises questions about their function in male and female sea bass. Gpera expression was mainly restricted to brain and pituitary in both sexes while gperb had a widespread tissue distribution with higher expression levels in gill filaments, kidney and head kidney. Both receptors were detected in the hypothalamus and pituitary of both sexes and significant changes in gpers expression were observed throughout the annual reproductive season. In female pituitaries, gpera showed an overall increase in expression throughout the reproductive season while gperb levels remained constant. In the hypothalamus, gpera had a higher expression during vitellogenesis and decreased in fish entering the ovary maturation and ovulation stage, while gperb expression increased at the final atresia stage. In males, gpers expression was constant in the hypothalamus and pituitary throughout the reproductive cycle apart from the mid- to late testicular development stage transition when a significant up-regulation of gpera occurred in the pituitary. The differential sex, seasonal and subtype-specific expression patterns detected for the two novel gper genes in sea bass suggests they may have acquired different and/or complementary roles in mediating estrogens actions in fish, namely on the neuroendocrine control of reproduction.