Branchial expression of an aquaporin 3 (AQP-3) homologue is downregulated in the European eel Anguilla anguilla following seawater acclimation

摘要: SUMMARY A cDNA encoding the homologue of mammalian aquaporin 3 (AQP-3) was isolated by reverse transcription—polymerase chain reaction from gill the European eel. The derived amino acid sequence shares 67-70% homology with other vertebrate AQP-3 homologues. Northern blot analysis revealed two AQP-3-specific mRNA species 2.4 kb and 7 kb. is expressed predominantly in eye, oesophagus, intestine (as found mammals) the gill; no expression could be demonstrated stomach only low and sporadic levels kidney. Quantitative studies that, following 3-week acclimation freshwater (FW)-adapted yellow silver eels to seawater (SW), transcript abundance reduced by 76% and 97%, respectively. half time branchial downregulation in yellow eels approximately 10 h, with a maximal 94% decrease expression after 2 days SW (compared time-matched FW controls). However, fish acclimated for more than 4 days, fall abundance recovered slightly, such that after weeks, 16% in time-matched controls. potential roles this isoform in water or solute transport eel are discussed.