Expression of the Na-K-2Cl Cotransporter in Branchial Mitochondrion- Rich Cells of Mozambique Tilapia (Oreochromis mossambicus) Subjected to Varying Chloride Conditions

733 T he Na-K-2Cl cotransporter (NKCC) mediates the coupled movements of Na, K, and Clacross plasma membranes of animal cells. The NKCC plays an important role in ion movements across polarized epithelia and is also known to be involved in regulating cell volume and intracellular Cllevels (Lytle and Forbush 1996, Haas and Forbush 1998). The NKCC is a member of the Na-coupled group of cation-chloride cotransporters (CCCs), a family which includes K-Cl cotransporters (KCCs). Three Na-coupled CCCs have been described to date (Mark and David 1996, Haas and Forbush 2000). The “secretory” Na-K-2Cl cotransporter, NKCC1, is widely distributed in mammalian tissues, and is especially prominent in basolateral membranes of secretory Expression of the Na-K-2Cl Cotransporter in Branchial MitochondrionRich Cells of Mozambique Tilapia (Oreochromis mossambicus) Subjected to Varying Chloride Conditions Jiun-Lin Horng1 and Li-Yih Lin2,* 1Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan 2Department of Life Science, National Taiwan Normal University, Taipei 106, Taiwan