1939MOLECULAR,CELLULAR,ANDDEVELOPMENTALBIOLOGY2009PoultryScience88:1939–1947doi:10.3382/ps.2009-00032Keywords:reducedfolatecarrier,folatesupplementation,molecularcloningandtissuedistribution,messengerribonucleicacidexpression,layinghenABSTRACTThereducedfolatecarrier(RFC)hasbeenpostulatedtobeamajorentityforfolatetrans-portactivityinhumansandothermammals.However,therearelimitedreportsoftheimportanceofRFCinanaviansystem.Inthecurrentstudy,therefore,themolecularcloningandtissuedistributionofRFC,aswellastheeffectofdietaryfolatesupplementationontheexpressionofthistransporter,wereinvestigatedinthechicken.ShaverWhitelayinghens(n=8perdiet)received3wheat-baseddietscontainingthefollowing:1)nosupplementalfolate,2)folicacid(10.00mg/kg),or3)5-methyltetrahydrofolate(11.30mg/kg)for21d.ThemRNAexpressionlevelswereanalyzedbyquantita-tivereal-timePCR.TheresultsshowedthattheclonedpartialRFCcDNAcontainingthefullcodingregionfromduodenumwas99%homologoustothereferencegeneavailableinGenBank.AbroadexpressionprofileofRFCtranscriptswasobserved,withRFCmRNAdetectedinthebrain,liver,kidney,spleen,lung,intes-tine,ovary,andtestis,aswellasothertissues.Real-timePCRanalysisrevealedthatnosignificantdiffer-ences(P>0.05)duetodietwerefoundinthemRNAlevelsofRFCintheduodenumandcecum.However,comparedwiththebasaldiet,jejunalmRNAlevelsofRFCweredecreased(P<0.05)inhensfedwiththe5-methyltetrahydrofolatediet,butthereductiondidnotreachsignificance(P=0.077)inthehensfedthefolicaciddiet.Overall,thecurrentstudydemonstratedthattheRFCcDNAcontainingthefullcodingregionwassuccessfullyclonedfromtheduodenumoflayinghens.ThewidetissuedistributionofRFCtranscriptsissuggestiveofanimportantroleofRFCintheprocessoffolatetransportinthechicken.Moreover,dietaryfolatesupplementationcoulddownregulatethejejunalmRNAexpressionofRFC.SuchfindingswilllaythefoundationoffutureworkinvolvingtheRFCinaviansystems,includinglayinghens.Molecularcloningandtissuedistributionofreducedfolatecarrierandeffectofdietaryfolatesupplementationontheexpressionofredu...
