Reproduction and Genetics Group, School of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, UK.
Gen Comp Endocrinol. 2012 Dec 1;179(3):384-99. doi: 10.1016/j.ygcen.2012.07.033. Epub 2012 Oct 1.
In the present study, we developed and validated real-time quantitative RT-PCR assays for a suite of genes involved in the brain-pituitary gonadal axis in fish including kisspeptin genes and its receptor (Kiss1, kiss2, kissr4) and gonadotropin-releasing hormone genes (sbGnRH, sGnRH, cGnRHII) in the brain, and gonadotropin genes (fshβ and lhβ) in the pituitary. Sex steroid profiles (T and 11-KT) and gonadal development were also studied over a full annual reproductive cycle in adult male sea bass. The cDNA partial sequence of sea bass kissr4 encoding 185 amino acids showed a high degree of conservation with other fish kissr4 subtype. Results clearly showed a seasonal profile for Kiss1, kiss2 and kissr4 mRNAs. Kissr4, fshβ and lhβ levels increased gradually and peaked during spermatogenesis (January) while Kiss1, kiss2, cGnRH-II as well as steroids showed peaks during early spawning (March). No significant seasonal changes were observed for sbGnRH and sGnRH expression. These results support the possible involvement of the kiss genes and their receptor (kissr4) in the seasonal control sea bass reproduction. However, a lack of correlation between kiss genes and sbGnRH expression and the mismatch between kisspeptin and the onset of gonadotropin surge contrast with previous findings.
在本研究中，我们开发并验证了鱼类脑垂体性腺轴相关基因的实时定量 RT-PCR 检测方法，包括 Kisspeptin 基因及其受体（Kiss1、kiss2、kissr4）和促性腺激素释放激素基因（sbGnRH、sGnRH、cGnRHII）在脑内，以及促性腺激素基因（fshβ和 lhβ）在垂体中的表达。我们还研究了成年雄性鲈鱼在整个年度生殖周期中的性类固醇谱（T 和 11-KT）和性腺发育情况。鲈鱼 kissr4 的 cDNA 部分序列编码 185 个氨基酸，与其他鱼类 kissr4 亚型具有高度保守性。结果清楚地显示了 Kiss1、kiss2 和 kissr4 mRNAs 的季节性特征。Kissr4、fshβ 和 lhβ 水平逐渐升高，并在精子发生期（1 月）达到峰值，而 Kiss1、kiss2、cGnRH-II 以及类固醇在早期产卵期（3 月）达到峰值。sbGnRH 和 sGnRH 的表达没有明显的季节性变化。这些结果支持 kiss 基因及其受体（kissr4）可能参与了鲈鱼的季节性繁殖调控。然而，Kiss 基因与 sbGnRH 表达之间缺乏相关性，以及 Kisspeptin 与促性腺激素激增的起始时间不匹配，与之前的研究结果不一致。
