Expression of Maturation-Related Genes and Leptin during Sexual Maturation in the Female Goldfish: Effects of Exogenous Kisspeptin

Abstract

Kisspeptin (Kiss) and its cognate receptor, kisspeptin receptor (KissR G protein coupledreceptor 54, GPR54), have recently been recognized as potent regulators of reproductionin teleosts. Additionally, leptin plays an important role in energy homeostasis andreproductive function in teleosts. The purpose of this study was to examine differencesin the concentration of the hormones of the Kiss/KissR system and leptin and theexpression of their underlying genes, all of which are involved in the sexual maturationof female goldfish, Carassius auratus, following treatment with Kiss. The expression levels of KissR increased after the Kiss injection. Furthermore, the peptide hormone leptin also increased after the injection (in vivo and in vitro). Additionally, the expression of GnRH and GTHs (GTHα, FSHβ, and LHβ) increased in the brain and pituitary (in vitro and in vitro). These results support the hypothesis that Kiss plays important roles in the direct regulation of the hypothalamus-pituitary-gonad axis and leptin in goldfish. Therefore, we suggest that Kiss system gene expression is correlated with energy balance and reproduction. energy homeostasis and reproductive function in teleosts. The purpose of this study was to examine differences in the concentration of the hormones of the Kiss/KissR system and leptin and the expression of their underlying genes, all of which are involved in the sexual maturation of female goldfish, Carassius auratus, following treatment with Kiss. The expression levels of KissR increased after the Kiss injection. Furthermore, the peptide hormone leptin also increased after the injection (in vivo and in vitro). Additionally, the expression of GnRH and GTHs (GTHα, FSHβ, and LHβ) increased in the brain and pituitary (in vitro and in vitro). These results support the hypothesis that Kiss plays important roles in the direct regulationof the hypothalamus-pituitary-gonad axis and leptin in goldfish. Therefore, we suggestthat Kiss system gene expression is correlated with energy balance and reproduction.