盐度对青海湖裸鲤生长及渗透调节基因的影响

Effects of Different Salinities on Growth and Osmotic Regulation Gene Expression of Gymnocypris przewalskii

为探究青海湖特有珍稀鱼种青海湖裸鲤的盐度适应性机制,对青海湖裸鲤受盐度胁迫后的生长性能进行测定,qPCR检测渗透调节基因Na^(+)/K^(+)/2Cl^(-)共转运蛋白1(NKCC1)基因、Na^(+)/HCO^(-)_(3)共转运蛋白1(NBC1)基因、Na^(+)/H^(+)交换离子1(NHE1)基因和水通道蛋白1(AQP1)基因的表达。试验结果显示:不同盐度下青海湖裸鲤的各项生长指标存在显著差异(P<0.05);盐度的升高影响了青海湖裸鲤的生长发育,青海湖裸鲤的生长状况与盐度呈负相关关系。NKCC1、NBC1、NHE1、AQP1基因在不同盐度处理组青海湖裸鲤的鳃、肾脏和肝脏中均有表达,且表现出一定的组织特异性;NKCC1、NBC1、NHE1、AQP1基因参与了青海湖裸鲤机体内、外渗透压的调节,且因盐度、组织和胁迫时间的不同而表达水平也不同,反映出鳃和肾脏为主要的渗透压调节器官。本试验结果将为探讨青海湖裸鲤洄游后的生存状况及其盐度适应机制提供理论依据,及为黄河上游土著鱼类种质资源的保护和人工增殖放流提供理论指导。

Qinghai Lake is the largest inland brackish lake in China.The salinity adaptation mechanism of Gymnocypris przewalskii,a unique and rare fish species living in it,needs to be clarified urgently.Therefore,the growth performance and osmotic regulation genes of G.przewalskii were investigated after salinity stress by physiological index and qPCR and Na^(+)/K^(+)/2Cl^(-)cotransporter 1(NKCC1),Aquaporin 1(AQP1),Na^(+)/H^(+)exchange 1(NHE1)and Na^(+)/HCO^(-)_(3)exchange 1(NBC1)genes were detected.The results showed that there were significant differences in the growth indicators of G.przewalskii under different salinities(P<0.05),indicating that the increase in salinity affected the development of G.przewalskii,and that the growth status were negatively correlated with salinity.NKCC1,NBC1,AQP1 and NHE1 genes were expressed in the gills,kidneys and livers under different salinities,showing certain tissues specificity.It was found that that NKCC1,AQP1,NHE1 and NBC1 genes were involved in the regulation of osmotic pressure of G.przewalskii,with varying the expression level with different salinities,tissue and stress time,reflecting that the gill and kidney were the main organ regulating osmotic pressure.The findings provided a theoretical basis for exploring the survival status and salinity adaptation mechanism of G.przewalskii after migration in Qinghai Lake,and a theoretical guidance for the protection and artificial proliferation and release of native fish germplasm resources in the upper reaches of the Yellow River.