Molecular cloning of cDNA of gonadotropin-releasing hormones in the Chinese sturgeon (Acipenser sinensis) and the effect of 17 beta-estradiol on gene expression
The Chinese sturgeon, Acipenser sinensis, is a rare and large-sized anadromous bony fish and understanding of its reproductive regulation is a precondition for controlled reproduction. In this study, two gonadotropin-releasing hormone (GnRH) precursor cDNAs, AsGnRH1 (mammalian type) and AsGnRH2 (chicken type 2), were sequenced in A. sinensis. The precursor cDNAs of the AsGnRH1 and AsGnRH2 are 381 and 649 base pairs (bp), encoding signal peptide plus precursors of 92 and 86 amino adds, respectively. Multiple sequence alignment suggests that AsGnRH1 and AsGnRH2 decapeptides are highly conserved among vertebrates. Besides, AsGnRH1 had closer evolutionary relationship with tetrapods, while AsGnRH2 was conservatively grouped with teleosts in the phylogenetic analysis. Tissue distribution analysis shows that AsGnRH2 is exclusively transcribed in the brain, whereas AsGnRH1 exhibits more extensive tissue distribution including brain, liver, spleen and gonad. Furthermore, Chinese sturgeons were subcutaneously implanted with 17 beta-estradiol (E2) and the effect of E2 on brain GnRH mRNA levels was evaluated by real-time PCR. A significant increase in AsGnRH1 and AsGnRH2 mRNA levels is detected in fish receiving E2 implantation compared to controls after one month (P < 0.05). These results indicate that E2 exerts positive feedback effects on the transcription of the two GnRHs in immature Chinese sturgeon. (C) 2013 Elsevier Inc. All rights reserved.
英文摘要:
The Chinese sturgeon, Acipenser sinensis, is a rare and large-sized anadromous bony fish and understanding of its reproductive regulation is a precondition for controlled reproduction. In this study, two gonadotropin-releasing hormone (GnRH) precursor cDNAs, AsGnRH1 (mammalian type) and AsGnRH2 (chicken type 2), were sequenced in A. sinensis. The precursor cDNAs of the AsGnRH1 and AsGnRH2 are 381 and 649 base pairs (bp), encoding signal peptide plus precursors of 92 and 86 amino adds, respectively. Multiple sequence alignment suggests that AsGnRH1 and AsGnRH2 decapeptides are highly conserved among vertebrates. Besides, AsGnRH1 had closer evolutionary relationship with tetrapods, while AsGnRH2 was conservatively grouped with teleosts in the phylogenetic analysis. Tissue distribution analysis shows that AsGnRH2 is exclusively transcribed in the brain, whereas AsGnRH1 exhibits more extensive tissue distribution including brain, liver, spleen and gonad. Furthermore, Chinese sturgeons were subcutaneously implanted with 17 beta-estradiol (E2) and the effect of E2 on brain GnRH mRNA levels was evaluated by real-time PCR. A significant increase in AsGnRH1 and AsGnRH2 mRNA levels is detected in fish receiving E2 implantation compared to controls after one month (P < 0.05). These results indicate that E2 exerts positive feedback effects on the transcription of the two GnRHs in immature Chinese sturgeon. (C) 2013 Elsevier Inc. All rights reserved.
关键词[WOS]:
HYPOTHALAMO-HYPOPHYSEAL SYSTEM
; PITUITARY-GONAD AXIS
; GNRH-II GENE
; FUNCTIONAL EVOLUTION
; 3 FORMS
; FISH
; BRAIN
; RECEPTORS
; CHICKEN
; IDENTIFICATION
Molecular cloning of cDNA of gonadotropin-releasing hormones in the Chinese sturgeon (Acipenser sinensis) and the effect of 17 beta-estradiol on gene expression.pdf（1701KB）
Molecular cloning of cDNA of gonadotropin-releasing hormones in the Chinese sturgeon (Acipenser sinensis) and the effect of 17 beta-estradiol on gene expression.pdf
