tailieunhanh - Báo cáo khoa học: Osmotic stress sensing and signaling in fishes

In their aqueous habitats, fish are exposed to a wide range of osmotic con-ditions and differ in their abilities to respond adaptively to these variations in salinity. Fish species that inhabit environments characterized by signifi-cant salinity fluctuation (intertidal zone, estuaries, salt lakes, etc.) are eury-haline and able to adapt to osmotic stress. | ễFEBS Journal MINIREVIEW Osmotic stress sensing and signaling in fishes Diego F. Fiol and Dietmar Kultz PhysiologicalGenomics Group Department of AnimalScience University of California Davis CA USA Keywords euryhaline fishes osmoregulation osmosensing osmotic stress salinity adaptation stress signaling Correspondence D. Kultz Comparative Physiological Genomics Group Department of Animal Science One Shields Avenue Meyer Hall University of California Davis CA 95616 USA Fax 1 530 752 0175 Tel 1 530 752 2991 E-mail dkueltz@ Received 2 July 2007 accepted 7 September 2007 doi In their aqueous habitats fish are exposed to a wide range of osmotic conditions and differ in their abilities to respond adaptively to these variations in salinity. Fish species that inhabit environments characterized by significant salinity fluctuation intertidal zone estuaries salt lakes etc. are euryhaline and able to adapt to osmotic stress. Adaptive and acclimatory responses of fish to salinity stress are based on efficient mechanisms of osmosensing and osmotic stress signaling. Multiple osmosensors including calcium sensing receptor likely act in concert to convey information about osmolality changes to downstream signaling and effector mechanisms. The osmosensory signal transduction network in fishes is complex and includes calcium mitogen-activated protein kinase 14-3-3 and macromolecular damage activated signaling pathways. This network controls among other targets osmosensitive transcription factors such as tonicity response element binding protein and osmotic stress transcription factor 1 which in turn regulate the expression of genes involved in osmotic stress acclimation. In addition to intracellular signaling mechanisms the systemic response to osmotic stress in euryhaline fish is coordinated via hormone-and paracrine factor-mediated extracellular signaling. Overall current insight into osmosensing and osmotic stress-induced signal .