简介：ExpressedSequenceTag(EST)analysishaspioneeredgenome-widegenediscoveryandexpressionprofiling.Inordertoestablishageneexpressionindexinthericecultivarindica,wesequencedandanalyzed86,136ESTsfromninericecDNAlibrariesfromthesuperhybridcultivarLYP9anditsparentalcultivars.WeassembledtheseESTsinto13,232contigsandleave8,976singletons.Overall,7,497sequenceswerefoundsimilartotheexistingsequencesinGenBankand14,711arenovel.Thesesequencesareclassifiedbymolecularfunction,biologicalprocessandpathwaysaccordingtotheGeneOntology.WecomparedoursequencedESTswiththepubliclyavailable95,000ESTsfromjaponica,andfoundlittlesequencevariation,despitethelargedifferencebetweengenomesequences,Wethenassembledthecombined173,000riceESTsforfurtheranalysis.UsingthepooledESTs,wecomparedgeneexpressioninmetabolismpathwaybetweenriceandArabidopsisaccordingtoKEGG.Wefurtherprofiledgeneexpressionpatternsindifferenttissues,developmentalstages,andinaconditionalsterilemutant,aftercheckingthelibrariesarecomparablebymeansofsequencecoverage.Wealsoidentifiedsomepossiblelibraryspecificgenesandanumberofenzymesandtranscriptionfactorsthatcontributetoricedevelopment.