LAUSR

Abstract Selenium (Se) is an essential trace element for fish growth and performs its physiological functions mainly through incorporating into selenoproteins. It is well known that dietary Se regulates fish growth by controlling the synthesis of deiodinase, a kind of selenoproteins. However, recently, as many as 41 selenoproteins have been characterized in teleost fish. We propose a hypothesis if other selenoproteins, besides deiodinase, could also involve in the regulation of fish growth. In the present study, rainbow trout (Oncorhynchus mykiss) were fed diets supplemented with or without graded levels of Se (2, 4 or 6 mg/kg, from selenium yeast, Se-yeast) for 10 weeks. At the end of the feeding trial, fish growth and the expressions of a total of 28 selenoprotein genes in tissues have been evaluated. Results showed that dietary Se-yeast supplementation significantly increased fish growth (P