)belongtothenuclearreceptorsuperfamily,whichregulatesthebiosynthesisandmetabolismoflipids,andthedifferentiationandformationoflipocytes.)wasclonedbyRT-PCR.Sequencehomologyanalysisshowedthatrainbowtroutgenewassimilartothosereportedinothervertebratespecies.ThemRNAsequenceandthededucedaminoacidsequenceofrainbowtrout%–93.8%,respectively,withthoseofothervertebrates.TheDNA-bindingdomainandtheligand-bindingdomainofPPARαhavebeenhighlyconservedintheevolutionfromfishtohumans,whichshow88.0–99.6%aminoacidsequenceidentities,respectively,withthoseofothervertebrates.Phylogeneticanalysisindicatedthat)belongtothesamebranchofthephylogenetictree.Usingquantitativereal-timeRT-PCR,weobservedthatrainbowtroutmRNAwasexpressedpredominantlyinlipid,muscle,ovarian,renal,andintestinaltissues.