Salinity-dependent expression of ncc2 in opercular epithelium and gill of mummichog (Fundulus heteroclitus).

Mummichogs (Fundulus heteroclitus) can tolerate abrupt changes in environmental salinity because of their ability to rapidly adjust the activities of ionocytes in branchial and opercular epithelia. In turn, the concerted expression of sub-cellular effectors of ion transport underlies adaptive responses to fluctuating salinities. Exposure to seawater (SW) stimulates the expression of Na/K/2Cl cotransporter 1 (nkcc1) and cystic fibrosis transmembrane regulator (cftr) mRNAs in support of ion extrusion by SW-type ionocytes.