Gonadotropin-inhibitory hormone (GnIH) plays a critical role in regulating gonadotropin-releasing hormone (GnRH), gonadotropin hormone (GtH), and steroidogenesis. The Lpxrfa (the piscine ortholog of GnIH) system has been found to regulate fish reproduction. To gain insight into the role of Lpxrfa in the regulation of spotted scat (Scatophagus argus) reproduction, spotted scat Lpxrfa (ssLpxrfa), and its receptor (ssLpxrfa-r) were cloned and analyzed. Tissue distribution and expression patterns at the hypothalamo-pituitary-gonadal axis (HPG axis) of sslpxrfa and sslpxrfa-r mRNA were also investigated during gonadal development of spotted scat. The open reading frame (ORF) of the sslpxrfa was 606 bp encoding 201 amino acids and includes a putative signal peptide and two mature ssLpxrfa peptides with LPXRFamide motif at their C-terminus. The sslpxrfa-r ORF was 1449 bp encoding 482 amino acids and contracted a seven-hydrophobic transmembrane (TM) domain structure. The tissue distribution showe d that the sslpxrfa was highly expressed in hypothalami, gill, and the gonads. In addition, sslpxrfa-r was highly expressed in hypothalami, pituitaries, and the gonads. Quantitative real-time polymerase chain reaction (qPCR) revealed that sslpxrfa had the highest expression in the hypothalami and pituitaries, and the lowest expression in the gonads in stage V. During gonadal development, the expression of sslpxrfa-r was gradually increased in the hypothalami but reduced in the gonads. However, no obvious trend was observed in the pituitaries. The expression of sslpxrfa and sslpxrfa-r decreased significantly after injection with 17β-estradiol (E2). However, the expression of both sslpxrfa and sslpxrfa-r was not changed after injection with 17α-methyltestosterone(17α-MT) in the hypothalami. In addition, no changes were observed in the expression of fshβ and lhβ in the pituitaries after injecting ssLpxrfa-1. However, ssLpxrfa-2 could downregulate the expression of sbgnrh and fshβ in the hypothalami and pituitaries, respectively. Taken together, these findings suggested that ssLpxrfa may participate in E2 feedback in reproduction and regulate the reproductive axis of spotted scat.

中文翻译：

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LPXRFa及其受体在斑点小cat（Scatophagus argus）的下丘脑-垂体-性腺轴上的生殖调节。

促性腺激素抑制激素（GnIH）在调节促性腺激素释放激素（GnRH），促性腺激素激素（GtH）和类固醇生成中起关键作用。已经发现Lpxrfa（GnIH的鱼类直系同源物）系统调节鱼的繁殖。为了深入了解Lpxrfa在斑点小cat（Scatophagus argus）繁殖调控中的作用，克隆了斑点小L Lpxrfa（ssLpxrfa）及其受体（ssLpxrfa-r）并进行了分析。还研究了斑点小的性腺发育过程中sslpxrfa和sslpxrfa-r mRNA的下丘脑-垂体-性腺轴（HPG轴）的组织分布和表达模式。sslpxrfa的开放阅读框（ORF）为606 bp，编码201个氨基酸，包括一个推定的信号肽和两个在其C端带有LPXRFamide基序的成熟ssLpxrfa肽。sslpxrfa-r ORF为1449 bp，编码482个氨基酸，并具有七个疏水的跨膜（TM）结构域结构。组织分布表明，sslpxrfa在下丘脑，g和性腺中高表达。此外，sslpxrfa-r在下丘脑，垂体和性腺中高表达。实时定量聚合酶链反应（qPCR）显示，sslpxrfa在下丘脑和垂体中的表达最高，在V期的性腺中最低。在性腺发育期间，sslpxrfa-r的表达在下丘脑中逐渐增加。但减少了性腺。但是，垂体中没有观察到明显的趋势。注射17β-雌二醇（E2）后，sslpxrfa和sslpxrfa-r的表达明显降低。然而，下丘脑注射17α-甲基睾丸酮（17α-MT）后，sslpxrfa和sslpxrfa-r的表达均未改变。此外，注射ssLpxrfa-1后垂体中fshβ和lhβ的表达未见变化。但是，ssLpxrfa-2可能分别下丘脑和垂体中下调sbgnrh和fshβ的表达。综上所述，这些发现表明，ssLpxrfa可能参与生殖中的E2反馈并调节斑点小便的生殖轴。分别。综上所述，这些发现表明，ssLpxrfa可能参与生殖中的E2反馈并调节斑点小便的生殖轴。分别。综上所述，这些发现表明，ssLpxrfa可能参与生殖中的E2反馈并调节斑点小便的生殖轴。