Prolactin, cortisol, and extracellular osmolality regulate cftr, ostf1, and sgk1 in tilapia ionocytes

Objective: ) to further elucidate the basis of euryhalinity. We sought to determine whether prolactin (Prl) supports FW acclimation by counteracting osmotic and hormonal signals that initiate branchial responses to SW environments. Methods: experimental paradigms to characterize their regulation by environmental salinity, Prl, cortisol, and extracellular osmolality. Results: , as shown previously. Conclusions: . While hyperosmotic extracellular conditions and cortisol promote the activation of these genes during SW acclimation, Prl supports FW adaptation by suppressing these genes and promoting processes underlying active ion uptake. Thus, euryhaline tilapia adjust the ion-transporting activity of their branchial ionocytes to meet environmental demands by integrating multiple regulatory cues.