LAUSR

Nesfatin-1 is a naturally occurring orphan ligand in fish and mammals. Research in our lab resulted in the identification of an inhibitory role for nesfatin-1 on pituitary hormones (goldfish) and oocyte maturation (zebrafish). The present study is an extension of these original findings, and aimed to determine whether nesfatin-1 has any additional effects on HPG genes in male and female goldfish. We found that a single intraperitoneal (I.P) injection of synthetic nesfatin-1 (50 ng/g body weight) downregulated the expression of salmon gonadotropin-releasing hormone (sgnrh), chicken gnrh-II (cgnrh-II), kisspeptin receptor (gpr54a) and brain aromatase (cyp19a1b) mRNAs in the hypothalamus of both male and female goldfish at 15 minutes post-administration. In the pituitary of both males and females, nesfatin-1 reduced luteinizing hormone beta (lhβ) and follicle stimulating hormone beta (fshβ) mRNA expression at 60 minutes, and gpr54a mRNA at 15 minutes. Similarly, the gonadotropin receptors lhr and fshr were downregulated in the gonads. Meanwhile, gonadotropin inhibiting hormone (gnih), gnih receptor, kisspeptin 1 (kiss1) and gpr54a mRNA expression were in the gonads were increased post nesfatin-1 treatment. Nesfatin-1 negatively influences the steroidogenic acute regulatory protein, cytochrome P450 family 11 subfamily A member 1, anti-mullerian hormone and aromatase mRNAs. In agreement with these results, nesfatin-1 reduced plasma estradiol and testosterone in female and male goldfish circulation at 60 min post injection. The information generated through this research further solidified nesfatin-1 as an inhibitor of reproductive hormones in fish. The suppression of nesfatin-1 and related peptides could yield beneficial effects in fish reproduction and aquaculture.