A TRANSCRIPTOMIC STUDY ON, AND MOLECULAR BIOLOGY OF SEVERAL ION TRANSPORTERS AND WATER CHANNELS IN, THE GILLS OF THE CLIMBING PERCH, ANABAS TESTUDINEUS, EXPOSED TO FRESH WATER, SEAWATER, ENVIRONMENTAL AMMONIA OR TERRESTRIAL CONDITIONS

Abstract

The freshwater climbing perch, Anabas testudineus, is an obligate air-breathing euryhaline teleost which can survive in seawater, and has the unique ability to actively excrete ammonia when exposed to high concentrations of environmental ammonia or during emersion. The first objective of this study aimed to examine, using next-generation sequencing, the differential gene expressions in the gills of A. testudineus after exposure to seawater, high concentrations of environmental ammonia or terrestrial conditions. The second objective was to determine the branchial mRNA expression of several key transporters and water channels, Na+:Cl- co-transporter, Na+:K+:2Cl- cotransporter1, Na+/K+-ATPase a subunits, cystic fibrosis transmembrane conductance regulator, rhesus glycoproteins, Na+/H+ exchangers and aquaporins, in the gills of fish subjected to different experimental conditions. The third objective involved determining the protein expression and cellular localization of these transporters