Univ Montpellier, CNRS, IFREMER, IRD, UM, MARBEC, France.
Centre Scientifique de Monaco, Marine Biology Department, 8 Quai Antoine 1er, 98000, Monaco.
J Therm Biol. 2019 Oct;85:102422. doi: 10.1016/j.jtherbio.2019.102422. Epub 2019 Sep 20.
The responses of European sea bass to temperature increase and salinity decrease were investigated measuring mRNA expression levels of main genes involved in ion transport. Juvenile fish were pre-acclimated to seawater (SW) at 18 °C (temperate) or 24 °C (warm) for two weeks and then transferred for two weeks to either fresh water (FW) or SW at the respective temperature. Unlike temperate conditions, there is no change in Na/K-ATPase α1a (nka α1a) and Na/H exchanger 3 (nhe3) mRNA expression following FW transfer in warm conditions. This is linked to the high expression of these genes in warm SW compared to temperate SW. Na/Cl-cotransporter (ncc2a) expression however is increased following FW transfer in temperate and warm conditions. Main transporters involved in ion excretion (Na/K/2Cl-1 cotransporter, nkcc1 and cystic fibrosis transmembrane conductance regulator, cftr) as well as nitrogen excretion (Rh-glycoproteins, rhcg1 and rhbg) and acid-base regulation (V-H-ATPase, vha-a and b) are highly expressed in SW warm conditions vs FW warm. Overall, our results suggest a higher activation of ion transport processes in warm conditions and more strikingly in SW. This is linked to a strong interplay between diverse ion transporters in order to coordinate physiological responses at the gill level.
研究了欧洲鲈鱼对温度升高和盐度降低的反应，测量了参与离子转运的主要基因的 mRNA 表达水平。将幼鱼在 18°C（温和）或 24°C（温暖）下预先适应海水（SW）两周，然后在两周内转移到淡水（FW）或相应温度的 SW 中。与温和条件不同，在温暖条件下，FW 转移后 Na/K-ATPase α1a（nka α1a）和 Na/H 交换器 3（nhe3）mRNA 表达没有变化。这与温暖 SW 中这些基因的高表达有关，而与温和 SW 相比。然而，在温和和温暖条件下，FW 转移后 Na/Cl-共转运体（ncc2a）的表达增加。参与离子排泄（Na/K/2Cl-1 共转运体，nkcc1 和囊性纤维化跨膜电导调节剂，cftr）以及氮排泄（Rh-糖蛋白，rhcg1 和 rhbg）和酸碱调节（V-H-ATPase，vha-a 和 b）的主要转运体在温暖的 SW 条件下高度表达，而在 FW 温暖条件下则不高。总体而言，我们的结果表明，在温暖条件下，离子转运过程的激活更高，在 SW 中更为明显。这与多种离子转运体之间的强烈相互作用有关，以便在鳃水平上协调生理反应。
