Spotted Sea Bass (Lateolabrax maculatus) cftr, nkcc1a, nkcc1b and nkcc2: Genome-Wide Identification, Characterization and Expression Analysis Under Salinity Stress

The Na+/K+/2Cl− cotransporter (NKCC) and the cystic fibrosis transmembrane conductance regulator (CFTR) proteins play crucial roles in the transportation of Na+ and Cl−. In this study, we identified cftr, nkcc1a, nkcc1b and nkcc2 in spotted sea bass (Lateolabrax maculatus) genomic and transcriptomic databases. We also characterized these genes via phylogenetic and structural analyses. The results showed that both cftr and nkcc were highly conservative in L. maculatus. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis in ten tissues showed that cftr, nkcc1a and nkcc2 highly express in osmoregulatory organs such as gill, kidney and intestine. Furthermore, the expressions of cftr and nkcc1a in gill as well as nkcc2 in intestine were up-regulated by high salinity, indicating that these genes function potentially in osmoregulation. Our findings provided the insights into the cftr and nkcc functions in euryhaline teleost.