摘要
广盐性鱼类有着较为复杂的渗透调节机制,能够在较大盐度范围内存活并生长。通常认为鱼类在等渗环境下用于渗透调节的代谢能量最少,有利于鱼类生长。本实验首先根据不同盐度下花鲈血清渗透压对应水体渗透压的变化,计算得到花鲈的等渗点为11.4。而后进行海水淡化和淡水适应两个阶段的盐度实验,通过对花鲈两个阶段中血清渗透压、Na^+/K^+/Cl-浓度、Na^+-K^+-ATP酶(Na^+-K^+-ATPase,NKA)活性及其基因表达的测定,探讨了海水淡化对花鲈的生理影响与分子响应机制。在盐度实验中,Na^+和Cl-浓度变化和血清渗透压变化趋势一致,在淡化阶段显著下降,在淡水适应阶段逐渐恢复稳定,但仍低于起始水平。鳃组织中NKA基因表达结果显示,NKAα1a和NKAα1b的变化趋势与Na^+-K^+-ATP酶活性变化趋势基本一致,在淡化阶段显著下降,随后回升至稳定,不同的是,淡水适应后花鲈NKAα1a表达量与盐度30组无显著性差异,而NKAα1b表达量显著低于盐度30;NKAα3在淡化第1天,表达量显著降低,且在淡水(盐度0)环境下一直处于较低水平;NKAβ在淡水适应过程中的表达量总体高于淡化过程。相关性分析中,海水淡化阶段,Na^+-K^+-ATP酶和NKAα1a呈极显著相关。本研究通过对花鲈等渗点以及海水淡化和淡水适应阶段相关离子、酶、基因表达的测定,弥补有关花鲈等渗点研究的空白,同时为花鲈的淡化养殖提供一定的理论指导。
Euryhaline fish, which can survive and grow in a wide range of salinity environment, have a complex mechanism to deal with salinity change. It is generally believed that at the isotonic environment, the energy consumption of fish used for osmotic regulation is the least, which was beneficial to fish growth. No previous study has reported about the isotonic point in Lateolabrax maculatus. Therefore, in this study, the blood osmotic pressure,Na＋/K＋/Cl-concentration, Na＋-K＋-ATPase activity and relative gene expressions were detected during the periods of water desalination and freshwater adaptation. Result showed that the isotonic point of L. maculatus was11.4 according to the changing characteristics of the osmotic pressure in fish plasma and the corresponding osmotic pressure of different water salinities. During the experiment of water desalination, both the concentrations of Na＋, K＋ and Cl-and serum osmotic pressure were decreased significantly, with a slow recovery after freshwater adaptation.The results of mRNA expression of NKA genes in gill showed that the change trend of NKAα1 a and NKAα1 b was similar to Na＋-K＋-ATPase activity, except that the expression of NKAα1 a in fresh water was not significantly different from that of the 30 seawater group, but the expression level of NKAα1 b in fresh water was lower than 30 seawater group. After 1 day＇s water desalination, the expression level of NKAα3 decreased significantly,and remained low expression during fresh water adaptation. This study provided theoretical basis for desalination culture of L. maculatus.
作者
张晓燕
温海深
张凯强
刘阳
方秀
李昀
ZHANG Xiaoyan;WEN Haishen;ZHANG Kaiqiang;LIU Yang;FANG Xiu;LI Yun(Key Laboratory of Mariculture,Ocean University of China,Ministry of Education,Qingdao 266003,China;Key Laboratory of Breeding Lateolabrax Japonicus in Fujian,Fuding 355200,China)
出处
《水产学报》
CAS
CSCD
北大核心
2018年第8期1199-1208,共10页
Journal of Fisheries of China
基金
现代农业产业技术体系专项(CARS-47)
山东省自然科学基金(ZR2016CQ21)~~
关键词
花鲈
等渗点
盐度
淡化
渗透生理
Lateolabrax maculatus
isotonic point
salinity
desalination
osmotic physiology
