简介:TherootofPanaxginsengplantundergoesaspecificdevelopmentalprocesstobecomeabiosynthesisandaccumulationtissueforginsenosides.Toidentifyandanalyzegenesinvolvedinthebiosynthesisofginsenoside,weconstructedandcharacterizedafull-lengthcDNAlibraryfor6-year-oldNorthAmericanginseng.ThetiterofprimarycDNAlibraryis1.2×106pfu/mL,thetiterofamplifiedlibraryis2.6×1010pfu/mLandtherateofrecombinantisabove86%.Theinsertsizerangesfrom0.3to2.0kb.Sequencingresultsshowthat18of58genesarehighhomologoustothegenes(GBR5,GBR3andGBR1)knowninGenBank,whichareinvolvedinbiosynthesisofginsenosideinNorthAmericanginsengplant;16of58genesarenovelgenes.Thefull-lengthcDNAlibraryofNorthAmericanginsengroottissuesisessentialforthecloningofgenesknownanditisalsoaninitialkeyforthescreeningandcloningofnewgenes.
简介:Objective:Toanalyzethechangesofgeneexpressioninphenylbutyrateinduceddifferentiationofgliomacells.Methods:Theexpressionlevelsof14000genesingliomacellsbeforeandafterinducementwithsodiumphenyl-butyratefor2hor6dayswereevaluatedbycDNAarraytechniqueandprovedbymulti-dotblotting.Results:expressionof98genesingliomacellsshowedchangesaftertheinducement.Somegenesinvolvedintranscriptionandtranslationandsomeoncogenesaredown-regulated,whilesomegeneinvolvedindifferentiationorapoptosisareup-regulated.18unknownexpressionsequencingtag(EST)changedtoo.Conclusion:Ageneexpressionprofileassociatedwithdifferentiationofgliomacellswasestablished.
简介:Throughexploitingthehighhomologyofcerealcropgenes,membranouscDNAmicroarrayscontaining3311uniquericetranscripts(including1639cndosperm-derivedtranscriptsand1672maturestem-derivedtranscripts)wereusedformonitoringtheexpressionprofilesofl-leafstageseedlingsof4cerealcropspecies:rice,maize,sorghumandbarley.Afterhybridizingwith[P]labeledprobes,73.6%ofthearrayedgenesgeneratedreliablesignalsinallofthefourcerealcrops.Furtheranalysisrevealedthatamongthearrayedgenes,ahigherpercentageoftheendosperm-derivedtranscripts(86.6%)expressedthanthatofthematurestem-derivedgenes(60.9%),indicatingthatmostoftheendospermexpressedgenesfunctionedinyoungseedlingswhilcconsiderableamountofmaturestemtissueexpressedgenesdidnotexpress.Theseresultsalsoinferredthatsomegenesmightfunctiononlyatcertaindevelopmentalstages.Bycomparingtheobtainedprofdes,84geneswereidentifiedconstantlyexpressedinallthefourcerealcrops.Manyhousekeepinggenes,suchaspolyubiquitin,ubiquitinconjugatingenzymeandribosomalproteinswereincludedinthiscatalogue.Theexperimentalsoidentified14riceseedlingspecificallyexpressedgenes,including3bioticandabioticstressinducedgenesand1apoptosissuppressorencodinggeneBaxinhibitor-1.Thisinvestigationprovidedinvaluableinformationforcomparativegenomicsofgramineaemembers.
简介:Twostarch-branchingenzyme(SBE)inrice,isknowntobeakeyenzymeinamylopectinbiosynthesis.ThecDNAoftwoSBE(starch-branchingenzyme)genesSheIandShedencodingSBEⅠandSBEⅢ(twomajorisoformsinrice)wereclonedbyanimprovedRT-PCRtechnique,fromatemplatecDNAlibray,derivedfromthetotalmRNAsextractedfromtheimmatureseedsofajaponicariceWuyunjing7.DNAsequenceanalysisshowedthatthesizeoftheclonedSheIandShedcDNAswere2490and2481bplong,respectively,includingtheirentirecodingsequences.ComparisonanalysisindicatedthatthenucleotidesequenceofShe3wasthesameasthatofshed(GenbankAccessionNo.D16201)asreportedpreviously.Therewereonlyfourbase-pairsdifference,whichresultedinchangesoftwodeducedaminoacidsbetweentheclonedShe1cDNAandthereportedshe1(GenbankAccessionNo.D11082).TheclonedSheIandShedcDNAsmakeitpossibletoimprovericestarchqualitythroughgeneticengineering.