Molecular physiology of osmoregulation in eels and other teleosts: the role of transporter isoforms and gene duplication

This review focuses on recent developments in the molecular biology of ion and water transporter genes in fish and the potential role of their product s in osmoregulation in both freshwater and seawater environments. In partic ular details of isoforms of various ATPases, co-transporters, exchangers an d ion channels in the eel as well as other teleost species are described. M any of the teleost transporter isoforms discovered so far, appear to occur as twin or duplicate copies compared to their homologous counterparts in hi gher vertebrates, although these duplicate isoforms often have distinct tis sue-specific and developmental stage-dependent expression patterns. The pos sible meaning of this information will be examined in relation to the fish genome duplication debate. (C) 2001 Elsevier Science Inc. Ail rights reserv ed.