Effect of salinity and temperature on the expression of genes involved in branchial ion transport processes in European sea bass

• Published in: Journal of thermal biology Vol. 85; p. 102422
• Main Authors: Masroor, Waliullah, Farcy, Emilie, Blondeau-Bidet, Eva, Venn, Alexander, Tambutté, Eric, Lorin-Nebel, Catherine
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2019; Elsevier BV; Pergamon Press ; Elsevier [1975-....]
• Subjects: Acid-base regulation; Animals; Bass - genetics; Biodiversity and Ecology; Chloride transport; Conductance; Cystic fibrosis; Dicentrarchus labrax; Ecology, environment; Ecosystems; Environmental Sciences; Excretion; Fresh Water; Gene expression; Gene Expression Regulation; Gill; Gills - metabolism; Glycoproteins; H+-transporting ATPase; Hydrogen; Ion Transport; Ion transporter; Ions; Life Sciences; Membrane Transport Proteins - genetics; mRNA expression; Na+/H+-exchanging ATPase; Na+/K+-exchanging ATPase; Salinity; Salinity effects; Seawater; Temperature; Thermal acclimation; Ion transporter; Dicentrarchus labrax; Gill; Thermal acclimation; mRNA expression; Salinity; cftr anion channel; cod gadus-morhua; na+/k+-atpase; seawater-acclimated medaka; na+/k+/2cl(-) cotransporter; dicentrarchus-labrax; h+-atpase; chloride channel; functional classification; fresh-water
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/j.jtherbio.2019.102422

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. •The expression of various branchial ion transporters is increased at 24 °C.•The induction of ion transport processes is less striking in fresh water.•In warm seawater, CFTR seems to be a key player in the regulation of Cl− balance.•Transporters regulating H+ and nitrogen excretion are highly expressed at 24 °C.