Differential expression of gill Na + ,K + -ATPase alpha- and beta-subunits, Na + ,K + ,2Cl - cotransporter and CFTR anion channel in juvenile anadromous and landlocked Atlantic salmon Salmo salar

• Published in: Journal of Experimental Biology
• Main Authors: Nilsen, Tom O., Ebbesson, Lars O. E., Madsen, Steffen S., McCormick, Stephen D., Andersson, Eva, Björnsson, Björn Th., Prunet, Patrick, Stefansson, Sigurd O.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2007
• Subjects: Cystic Fibrosis Transmembrane Conductance Regulator; Gene Expression Regulation; Gills; Protein Isoforms; Protein Subunits; RNA; Messenger; Salmo salar; Sodium-Potassium-Chloride Symporters; Sodium-Potassium-Exchanging ATPase; Water-Electrolyte Balance; Atlantic salmon
• Online Access: https://portal.findresearcher.sdu.dk/da/publications/09f71550-d96e-11dc-860c-000ea68e967b; https://doi.org/10.1242/jeb.002873

Udgivelsesdato: August This study examines changes in gill Na(+),K(+)-ATPase (NKA) alpha- and beta-subunit isoforms, Na(+),K(+),2Cl(-) cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR I and II) in anadromous and landlocked strains of Atlantic salmon during parr-smolt transformation, and after seawater (SW) transfer in May/June. Gill NKA activity increased from February through April, May and June among both strains in freshwater (FW), with peak enzyme activity in the landlocked salmon being 50% below that of the anadromous fish in May and June. Gill NKA-alpha1b, -alpha3, -beta(1) and NKCC mRNA levels in anadromous salmon increased transiently, reaching peak levels in smolts in April/May, whereas no similar smolt-related upregulation of these transcripts occurred in juvenile landlocked salmon. Gill NKA-alpha1a mRNA decreased significantly in anadromous salmon from February through June, whereas alpha1a levels in landlocked salmon, after an initial decrease in April, remained significantly higher than those of the anadromous smolts in May and June. Following SW transfer, gill NKA-alpha1b and NKCC mRNA increased in both strains, whereas NKA-alpha1a decreased. Both strains exhibited a transient increase in gill NKA alpha-protein abundance, with peak levels in May. Gill alpha-protein abundance was lower in SW than corresponding FW values in June. Gill NKCC protein abundance increased transiently in anadromous fish, with peak levels in May, whereas a slight increase was observed in landlocked salmon in May, increasing to peak levels in June. Gill CFTR I mRNA levels increased significantly from February to April in both strains, followed by a slight, though not significant increase in May and June. CFTR I mRNA levels were significantly lower in landlocked than anadromous salmon in April/June. Gill CFTR II mRNA levels did not change significantly in either strain. Our findings demonstrates that differential expression of gill NKA-alpha1a, -alpha1b and -alpha3 isoforms may be important ...