Zhu Huaping, Liu Zhigang, Gao Fengying, Lu Maixin, Liu Yujiao, Su Huanhuan, Ma Dongmei, Ke Xiaoli, Wang Miao, Cao Jianmeng, Yi Mengmeng
Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China.
Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China.
Comp Biochem Physiol A Mol Integr Physiol. 2018 Oct;224:1-10. doi: 10.1016/j.cbpa.2018.05.017. Epub 2018 May 28.
Tilapia (Oreochromis mossambicus, O. urolepis hornorum, their hybrids O. mossambicus♀ × O. hornorum♂ and O. hornorum♀ × O. mossambicus♂) were exposed to a high salinity environment to evaluate their osmoregulatory responses. The plasma osmolality of all the tilapia species were elevated with the salinity challenge. The activities of Na/K-ATPase (NKA) in both the gill and kidney showed a similar increased change tendency compared with the control. The distribution of NKA α1 mRNA in all the examined tissues suggested that NKA α1 has a possible housekeeping role for this isoform. The amount of NKA α1 mRNA in the gill and kidney was elevated in the four fishes with similar expression patterns after transfer from freshwater to seawater. The NKAα1 mRNA expression levels in the gill reached their peak level at 24 h after transfer (P < 0.01) compared to the freshwater group, following decreases in the pretreatment level at 48 h (P > 0.05). However, the NKAα1 mRNA expression levels in the kidney were not significantly affected with increasing environmental salinity (P > 0.05). The differences in the responses to saltwater challenge may be associated with differences in saltwater tolerance between the four tilapia. The drastic increase in the plasma osmolality, NKA activities and mRNA expression suggested that the hybrids (O. mossambicus♀ × O. hornorum♂) possess heterosis in salinity responsiveness compared to that of both the parents, indicating a maternal effect on the salinity tolerance of the tilapia hybrids. This study provides a theoretical basis to further study the mechanism of fish osmoregulation response to salinity challenge.
将罗非鱼（莫桑比克罗非鱼、霍氏罗非鱼及其杂交种莫桑比克罗非鱼♀×霍氏罗非鱼♂和霍氏罗非鱼♀×莫桑比克罗非鱼♂）暴露于高盐度环境中，以评估它们的渗透调节反应。随着盐度挑战，所有罗非鱼品种的血浆渗透压均升高。与对照组相比，鳃和肾脏中钠钾ATP酶（NKA）的活性呈现出相似的增加变化趋势。NKA α1 mRNA在所有检测组织中的分布表明，NKA α1可能对该亚型具有看家作用。从淡水转移到海水后，四种鱼鳃和肾脏中NKA α1 mRNA的量均升高，且表达模式相似。与淡水组相比，转移后24小时鳃中NKAα1 mRNA表达水平达到峰值（P<0.01），48小时时预处理水平下降（P>0.05）。然而，随着环境盐度增加，肾脏中NKAα1 mRNA表达水平未受到显著影响（P>0.05）。对盐水挑战反应的差异可能与四种罗非鱼之间的耐盐性差异有关。血浆渗透压、NKA活性和mRNA表达的急剧增加表明，杂交种（莫桑比克罗非鱼♀×霍氏罗非鱼♂）在盐度反应性方面相对于双亲具有杂种优势，这表明母体对罗非鱼杂交种的耐盐性有影响。本研究为进一步研究鱼类对盐度挑战的渗透调节反应机制提供了理论依据。
