碳酸盐碱度胁迫下鲤鱼氨排泄相关基因的差异表达

Ammonia Eexcretion Related Genes Expression of Common Carp Under the Stress of Carbonate Alkalinity

鲤鱼(Cyprinus carpio)是我国主要淡水养殖鱼类之一,且具有一定的盐碱耐受性,可以在偏碱水体中存活生长。为了了解其对不同碱度的耐受性,以及在碱胁迫环境下的基因表达变化,以鲤鱼为试验材料,使用一定pH值不同碳酸盐碱度水对其进行胁迫试验。选取鱼类氨排泄相关的候选基因,包括Rhesus血型相关糖蛋白基因(Rhesus blood group-associated glycoprotein,Rh),水通道蛋白基因(Aquaporin,AQP),催乳素基因(Prolactin,PRL),碳酸酐酶基因(Carbonic Anhydrase,CA),Na^+/K^+转运ATP酶基因(Na^+/K^+ transporting ATPase,NKA),钠氢交换体基因(sodium hydrogen exchanger,NHE)采用定量PCR方法检测其在不同碱度下的基因表达情况。结果表明上述基因随着碱度的升高在鳃、肠和肾3个组织中的总体表达水平较淡水对照显著升高,说明鲤鱼在碳酸盐碱胁迫条件下与氨排泄相关基因的表达上调。这些基因具有一定的空间表达差异性,具体结果为:胁迫过程中主要在鳃中表达的基因为AQP3A、PRLRA、NHE7,在肾中表达的基因为PRL,在肠中表达的基因是RHAG、RHBG2、RHCG1。这些基因在碱胁迫环境下的表达变化为解析鱼类体内渗透压调节调控机制具有重要意义。

Common carp （ Cyprinus carpio ） is one of the most important aquaculture species in China and with certain alkalisaline tolerance. In order to understand the common carp genes expression in different alkali-saline water, we studied the candidate ammonia excretion related genes ： Rh （ Rhesus blood group-associated glycoprotein ） , AQP （ Aquaporin ） , PRL （ Prolactin ） , CA （ Carbonic Anhydrase ） , NKA （ Na＋/K＋ transporting ATPase ） , NHE （ Sodium Hydrogen Exchanger ） expression at a rising carbonate alkalinity gradient in a certain pH value by quantitative PCR method. Results showed that with the rise of carbonate alkalinity value, the overall expression of these genes in gill, kidney and intestine are up-regulated compared with freshwater controls. And AQP3A, PRLRA, NHE7 are mainly expressed in gill ; PRL are mainly expressed in kidney ; RHAG, RHBG2, RHCG1 are mainly expressed in intestine under the stress of carbonate alkalinity. The changes of these genes expression in different level of carbonate alkalinity can provide insights into the mechanism of osmotic regulation for fish.