Cheng Chang-Hong, Yang Fang-Fang, Liao Shao-An, Miao Yu-Tao, Ye Chao-Xia, Wang An-Li
Key Laboratory of Ecology and Environmental Science of Guangdong Higher Education Institutes, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631, People's Republic of China,
Fish Physiol Biochem. 2015 Apr;41(2):495-507. doi: 10.1007/s10695-015-0025-1. Epub 2015 Jan 20.
Waterborne ammonia has become a persistent pollutant of aquatic habitats. The exposure to ammonia stress can reduce growth in a wide range of aquatic organisms. To assess the effect of ammonia exposure on the growth hormone/insulin-like growth factors (GH/IGF) axis, we identified and characterized GHR1, GHR2 and IGF-1 from pufferfish. Comparative analysis showed that these genes shared high identity and similarity with corresponding genes in other fish species. The transcripts of these genes were widely expressed in all tested tissues. The highest level of GHR1 mRNA was found in the brain, whereas GHR2 and IGF-1 mRNA levels were the highest in the liver. Following acute ammonia exposure (100 mg/L total ammonia-nitrogen), GHR2 expression in the liver did not change at 6 h and then significantly decreased at 12, 24 and 48 h, whereas GHR1 and IGF-1 expressions were significantly down-regulated at 6, 12, 24 and 48 h, respectively. These results indicated that ammonia stress decreased the expression of GH/IGF axis genes, which might have negative effect on the growth and development of pufferfish.
水体氨已成为水生栖息地的一种持久性污染物。暴露于氨胁迫会降低多种水生生物的生长。为了评估氨暴露对生长激素/胰岛素样生长因子（GH/IGF）轴的影响，我们从河豚中鉴定并表征了GHR1、GHR2和IGF-1。比较分析表明，这些基因与其他鱼类物种中的相应基因具有高度的同一性和相似性。这些基因的转录本在所有测试组织中广泛表达。GHR1 mRNA水平在脑中最高，而GHR2和IGF-1 mRNA水平在肝脏中最高。急性氨暴露（总氨氮100 mg/L）后，肝脏中GHR2的表达在6小时时没有变化，然后在12、24和48小时时显著下降，而GHR1和IGF-1的表达分别在6、12、24和48小时时显著下调。这些结果表明，氨胁迫降低了GH/IGF轴基因的表达，这可能对河豚的生长和发育产生负面影响。
