数量性状位点定位和全基因组关联分析的方法与软件综述(英文)

数量性状位点定位和全基因组关联分析的方法与软件综述(英文)
数量性状位点定位和全基因组关联分析的方法与软件综述(英文)

浙江大学学报(农业与生命科学版) 40(4)

:379~386,2014

JournalofZhejiangUniversity(Agric.&LifeSci.)http://www.journals.zju.edu.cn/agrE‐mail:zdxbnsb@zju.edu.cn

DOI:10.3785/j.issn.1008‐9209.2014.04.212

Foundationitem:ProjectsupportedbytheNationalBasicResearchProgramofChina(973)(Nos.2010CB126006and2011CB109306),andtheNationalScienceFoundationofChina(No.31371250).

Correspondingauthor:ZhuJun,E‐mail:jzhu@zju.edu.cn

Received:2014

04

21;Accepted:2014

05

28;Publishedonline:2014

07

24

URL:http://www.cnki.net/kcms/doi/10.3785/j.issn.1008‐9209.2014.04.212.html

Toolsforquantitativetraitlocusmappingandgenome‐wideassociationstudymapping:areview

Md.MamunMonir1,ZhuJun1,2,3倡(1.DepartmentofAgronomy,CollegeofAgricultureandBiotechnology,ZhejiangUniversity,Hangzhou310058,China;2.DepartmentofMathematics,ZhejiangUniversity,Hangzhou310058,China;

3.ResearchCenterforAirPollutionandHealth,ZhejiangUniversity,Hangzhou310058,China)

Summary Oneofthekeyobjectivesingenomicsstudiesistounderstandgeneticarchitectureofcomplextraits

anddiseases.Quantitativetraitlocus(QTL)mappingandgenome‐wideassociationstudy(GWAS)mappinghavebeenusingtodissectgeneticarchitectureofcomplextraitsanddiseasesthatassistsingeneticbreedinganddrug

discovery.Inthispaper,wereviewedQTLmappingandGWASmappingmethodologiesandsoftwaresforcomplextraitsordiseasesanalysis.PLINK,TASSEL,SNPassoc,GenABELandProbABELaremostpopular

softwaresprovidingmanyusefulfunctionsforGWASmapping.PLINKisthehighestpopularopen‐sourcewhole

genomeassociationanalysistoolset,whichimplementsanumberoffunctionsforSNPdataanalysis.TASSELisanotherpopularsoftware,implementsQ+Kcompositeapproachforassociationmapping.SNPassoc,GenABELandProbABELarepopularopensourceRpackagesusingforassociationmapping.WehavebrieflydescribedabovepopularsoftwaresforGWASmappingandhavedescribedimplementedfunctionsinQTXNetworksoftwareforGWASmappingofquantitativetraitwithmarkers(QTLs),SNPs(QTSs),transcripts(QTTs),proteins(QTPs),andmetabolites(QTMs).WealsodescribesomeotherpopularsoftwaressuchasWindowsQTLCartographer,QTLExpress,MapManagerQTX,R/qtlandQTLNetworkforQTLmapping.Keywords complextraits;linkagemapping;associationmapping;QTXNetworkCLCnumber Q939.96 Documentcode A

数量性状位点定位和全基因组关联分析的方法与软件综述(英文).浙江大学学报(农业与生命科学

版),2014,40(4):379386

马蒙1,朱军1,2,3倡(1.浙江大学农业与生物技术学院农学系,杭州310058;2.浙江大学数学系,杭州310058;3.浙江大学空气污染与健康研究中心,杭州310058)

摘要 基因组学研究的主要目标是剖析复杂性状和疾病的遗传结构.数量性状位点(quantitativetraitlocus,QTL)定位和全基因组关联分析(genome‐wideassociationstudy,GWAS)已经应用于遗传育种和药物研制,分析

复杂性状和复杂疾病的遗传结构.本文回顾了分析复杂性状和复杂疾病的QTL定位和GWAS的作图方法和软件.PLINK,TASSEL,SNPassoc,GenABEL和ProbABEL是流行的软件,为GWAS提供了许多有用的功能.PLINK是目前最流行的开源全基因组关联分析的工具集,它聚合了用于分析SNP数据的许多功能.TASSEL是

浙江大学学报(农业与生命科学版)

另一种流行的软件,整合了Q+K关联分析的诸多方法.SNPassoc、GenABEL和ProbABEL是应用于关联分析的开源代码R软件包.本文对上述提及的GWAS关联分析流行软件作了简要介绍,并介绍了新研制的QTXNetwork分析软件,它可分析QTL和GWAS定位数量性状SNP(QTS)、数量性状转录子(QTT)、数量性状蛋白子(QTP)和数量性状代谢子(QTM).本文还介绍了一些常用的分析软件,例如WindowsQTLCartographer,QTLExpress,MapManagerQTX,R/qtl和QTLNetwork.

关键词 复杂性状;连锁定位;关联定位;QTXNetwork软件

Significantimprovementinthefieldofcomplextraitanalysiswastheformationoflargecollectionsofmolecularmarkers,whichcouldbeusedtoconstructdetailedgeneticmapsofbothexperimentalanddomesticatedspecies[1].Withconvenienceofhighdensemarkers,itisnowconceivabletounderstandmoreregardinggeneticarchitectureofcomplextraitsanddiseases.Traditionalquantitativetraitlocus(QTL)mappingwasadventwithmolecularmarkertechnology,whichhasbeenplayingasignificantroletocomprehendthegeneticarchitecturebehindMendelianandcomplextraitsordiseasessincelongtimeago.Nowwithconvenienceofmolecularandnextgenerationsequencingtechnology,genome‐wideassociationstudy(GWAS)mappingtakesplaceoftraditionalQTLmapping.However,QTLmappingisstillplayingasignificantroleforcomplextraitanalysisforanimalandplanttraits.AnumberofstudieshavebeenpreparedwithQTLmappingforanimalsandplants[28].Inthisreview,wehavedescribedsomeexistingQTLmethodologiesandpopularsoftwaresforcomplextraitsanalysis.WealsodescribedourQTLNetworksoftwareanditsimplementedfunctionsforanalysisofcomplextraits.Despitealotofsuccess,QTLmappingsuffersfromsomefundamentallimitations:OnlyallelicdiversitythatsegregatesbetweentwoparentsoftheparticularF2crossorwithintheRILpopulationcanbeassayed,andtheamountofrecombinationthatoccursduringthecreationoftheRILpopulationplacesalimitonthemappingresolution;however,GWASovercomesthementionedlimitationsofQTLanalysis[9].TherehavebeensuccessfullyidentifiedmanyvariantsandgeneticpathwaysassociatedwithtraitvariationbyperformingGWASwithincreasingsamplesizesormetaanalysesofmultiplestudiesforcomplextraitsthatcontributesgreatlytohumangeneticsanddrugdiscovery[1014].GWAShasalsobeenusedtodissectgeneticarchitectureofcomplextraitsforanimalsandplantstoassistbreedersindomesticationprocessofphenotypictraitsthatwillacceleratedevelopmentofhighproductiveanimalandplantlines[1521].

1 MethodsforQTLmappingandGWAS1.1 Highthroughputmarkers

Accordingtodetectionmethodandthroughput,allmolecularmarkerscanbedividedintothreemajorgroups[22]:low‐throughput,hybridization‐basedmarkerssuchasrestrictionfragmentlengthpolymorphisms(RFLPs);medium‐throughput,PCR‐basedmarkersthatincludesrandomamplificationofpolymorphicDNA(RAPD),amplifiedfragmentlengthpolymorphism(AFLP),simplesequencerepeats(SSRs);andhigh‐throughput(HTP),sequence‐basedmarkerssuchassinglenucleotidepolymorphisms(SNPs),whichareusuallyusedinwholegenomeassociationstudy.

1.2 MethodsforQTLmapping

Regionsofagenome,whichareresponsibleforvariationinthequantitativetraitofinterest,areknownasQTLandthegoalofQTLmappingistoidentifyallofsuchregions.QTLmappingisapowerfulmethodtoidentifyregionsofthegenomeusinglinkageinformationofflankingmarkersthatco‐segregateswithagiventrait.TherehavebeenanumberofapproachesdevelopedforQTLmapping.IntervalmappingwasadventasstandardmethodforQTLmapping,anditcoulddetectpositionaswellaseffectofQTLsituatedbetweentwoadjacentmarkers,proposedbyLanderet

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al.[23],however,itwasaffectedbybackgroundQTLsandgavebiasedestimateifmultipleQTLsweresituatedinthesamechromosome[2426].Usingselectedbackgroundmarkersoftheintervalthroughstepwiseselectionprocedure,amultipleregressionapproachforcontrollingtheeffectsofbackgroundQTLswasproposedindependentlybyZeng[2425]andJansenetal.[26],knownascompositeintervalmapping.Multipleintervalmapping(MIM)approachtoaddressmaineffectsaswellasepistasiseffectsofQTLswasproposed[27]basedonCockerham smodelforinterpretinggeneticparametersandthemethodofmaximumlikelihoodforestimatinggeneticparameters.Amixedmodelbasedcompositeintervalmapping(MCIM)wasproposedtreatingbackgroundmarkereffectsasrandomeffectsandQTLseffectsasfixedeffects,toaddressmaineffects,epistasiseffects,environmentinteractioneffectsofmaineffectsandepistasiseffects[28].OneofthedisadvantagesofCIMandMIMisthattheyarenotuniqueforestimationsincetheestimatedeffectsdependonthenumberofbackgroundmarkersusingascofactors.AnovelapproachtodissectgeneticarchitectureofcomplextraitswasproposedbyconsideringQTL‐QTLinteractions(epistasis),QTL‐by‐environmentinteractionsinmodelbasedonHandersonmethodIIItoaddressQTLsandBayesianmethodviaGibbssamplingtoestimatetheireffects[29].ItdoesnotincludethemarkersinmodelandtheestimatedeffectsofQTLsareunique.AmultivariatemixedmodelbasedmappingapproachwasdevelopedtomapmultipletraitsusingWilks lambdatestinsteadofF‐testtodeterminetheexistenceofQTLs[30].Thesetwomixedmodelapproaches(univariate[29]andmultivariate[30])areimplementedinQTLNetworksoftware,andareavailableathttp://ibi.zju.edu.cn/software/QTLNetwork.1.3 MethodsforGWAS

genome‐wideassociationstudy(GWAS),alsocalledwholegenomeassociationstudy(WGAS),aninspectiontolocategeneticvariantsassociatedwithtraitsofdifferentindividuals,generallyfocusesonassociationbetweenSNPandtraitslikecomplextraitsormajordiseasesoforganisms.TheperformanceofGWASdependsonstatisticalmethodologiesusingforanalysisandtherehavebeenproposedseveralstatisticalapproachesforGWASinseveraltimetoincreaseitsconsistencyandreliability.ThefirstsuccessfulGWASwaspublishedin2005andhadfoundtwosignificantSNPsassociatedwithage‐relatedmaculardegeneration(AMD)usingsingle‐markerassociations[31].Aunifiedmixedlinearmodelapproachwasdemonstratedin2006tosimultaneouslyaccountforpopulationstructureandunequalrelatednessamongindividuals[32].MultipointassociationmappingwithmodelbasedimputationmethodforinferringgenotypesatobservedandunobservedSNPsanddetectingcausalvariants[33]andgenome‐widerapidassociationusingmixedmodelandregression(GRAMMAR)forgenome‐widepedigree‐basedassociationanalysis[34]wereproposedin2007.Efficientmixed‐modelassociation(EMMA)wasproposedin2008forcorrectingpopulationstructureandgeneticrelatednessinmodelorganismassociationmapping[35].MethodEMMAX(EMMAexpedited)toremovecomputationalcomplexityofEMMA[36],compressedMLMandP3D(populationparameterpreviouslydetermined)approachestoreducecomputingtimeandimprovestatisticalpower[37],alogistickernel‐machinetestemployedforevaluatingthesignificanceofSNPsetforcase‐controlstudy[38],wereproposedin2010.Factoredspectrallytransformedlinearmixedmodels(FaST‐LMM)forreducingruntimeandmemoryuse[39];epistaticassociationmapping(EAM)approachforallthemain‐effectQTL,QTL‐by‐environmentinteractionsandQTL‐by‐QTLinteractionsestimatedbyempiricalBayesapproachforhomozygouscropcultivars[40]wereproposedin2011.Thereweremanynewmethodsproposedin2012:multi‐locusmixedmodelformappingcomplextraitsinstructuredpopulation[41];genome‐wideefficientmixedmodelassociation

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(GEMMA),whichisn(samplesize)timesfasterthanEMMA[42];variancecomponentsbasedtwo‐stepmethod,GRAMMAR‐Gamma,forextremelyfastcalculations,andtouseforassociationtestinginwhole‐genomeresequencingstudiesoflargehumancohorts[43];anapproximateconditionalandjointassociationanalysisthatcanusesummary‐levelstatisticsfromameta‐analysisofGWASandestimatelinkagedisequilibrium(LD)fromareferencesamplewithindividual‐levelgenotypedata,computationallyfastandapplicabletocase‐controldata[13].Recently,wehavedevelopednewmappingapproachesofdetectinggene‐to‐geneinteractionandgene‐to‐environmentinteractionbyGWASofquantitativetraitswithSNPs(QTSs),transcripts(QTTs),proteins(QTPs),andmetabolites(QTMs).Inourapproach,thegeneticmodelofcomplextraitscanincludecofactors(i.e.block,sex,age),geneticmaineffects(additiveA,dominanceD),epistasiseffects(additivebyadditiveAA,additivebydominanceAD,dominancebydominanceDD),andgene‐to‐environmentinteraction(AE,DE,AAE,ADE,andDDE).Wehaveusedmixedlinearmodelapproachesforunbiasedpredictionofgeneticmaineffects,epistasiseffects,andgene‐to‐environmentinteractioneffectsandalsoestimatetheheritabilityofindividualeffects.MappingsoftwaresGMDR‐GPUandQTXNetworkhavealsobeendevelopedbasedonGPUcomputationtechnologyandcanbeusedunderdifferentoperatingsystems(Windows,Unix,Mac).

1.4 ProblemsofmissingheritabilityinGWASMissingheritabilityisacommonprobleminGWASandmostofthecurrentstudiesfallinproblemofmissingheritability.Usingsimplestatisticalmodel(includingonlymaineffects,ignoredepistasisandenvironmentalinteractioneffects)owingtoheavycomputationalburdenandinappropriatemethodologiesismaincauseoflargeamountofmissingheritability[4448].Maineffectsaswellasvarioustypesofepistasisandenvironmentalinteractioneffectsusuallycontrolcomplextraitsanddiseases.Mappingepistaticinteractionsisbeingchallengedexperimentally,statisticallyandcomputationally;thestatisticalchallengeistheseverepenaltythatisincurredfortestingmultiplehypotheses,andcomputationalchallengeisthelargenumberofteststhatmustbeevaluated[49].ImplementedGPU‐computationmethodologyinQTXNetworksoftwarepermitsustousemorecomplexmodelthanotherexistingsoftware,whichcouldprovidemoreinformationaboutgeneticandenvironmentvariantsandtheirinteractions.

2 SoftwaresforQTLmappingandGWASandtheirapplications

2.1 SoftwaresforQTLmappingandtheirapplicationsTherehavebeenanumberofsoftwaresforQTLmapping.InthissectionwehavedescribedsomepopularsoftwaresandQTLNetworksoftware.

2.1.1 WindowsQTLCartographer WindowsQTLCartographerv2.5permitssingle‐markeranalysis,intervalmapping,compositeintervalmapping,Bayesianintervalmapping,multipleintervalmapping,multipletraitanalysisandcategoricaldataanalysis.Theinformationisavailableathttp://statgen.ncsu.edu/qtlcart/WQTLCart‐1.htmandathttp://statgen.ncsu.edu/qtlcart/WQTLCart.htm.

2.1.2 QTLExpress Web‐baseduser‐friendlypackagetomapQTLsinoutbredpopulations,publishedin2002[50].Allowpopulationfromlinecrosses,halfsibfamilies,nuclearfamiliesandsibpairs.UsingpermutationteststodetermineempiricalsignificancelevelsandbootstrappingtoestimateempiricalconfidenceintervalsofQTLlocationsareoptional.Fixedeffects/covariatescanbefittedandmodelsmayincludesingleormultipleQTLandresultsarepresentedintabularandgraphicalformat.URL:http://qtl.cap.ed.ac.uk.

2.1.3 MapManagerQTX Thissoftwarewasfirstpublishedin2001[51].ItcandetectandlocalizeQTLsbyfastregression‐basedsinglelocus

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association,simpleintervalmapping,compositeintervalmappingandsearchforinteractingQTLs.Thissoftwareisnolongerunderdevelopment.2.1.4 R/qtl ItisanRpackagepublishedin2003[52].HiddenMarkovmodel(HMM)technologyfordealingwithmissinggenotypedatawasused.ThemainHMMalgorithmswithallowanceforthepresenceofgenotypingerrors,forbackcross,intercross,andphase‐knownfour‐waycrosseswereimplemented.Thecurrentversion(1.31‐9)ofR/qtlincludesfacilitiesforestimatinggeneticmaps,identifyinggenotypingerrors,andperformingsingle‐QTLgenomescansandtwo‐QTL,two‐dimensionalgenomescans,byintervalmapping(withtheEMalgorithm),Haley‐Knottregression,andmultipleimputation.Allofthismaybedoneinthepresenceofcovariates(suchassex,ageortreatment).Onemayalsofithigher‐orderQTLmodelsbymultipleimputationandHaley‐Knottregression.Sourceofinformation:http://www.rqtl.organdavailabilityofpackage:http://www.rqtl.org/download/.2.1.5 QTLNetwork FirstversionofQTLNetworkwaspublishedin2008[53].Presentversion,QTLNetwork‐2.0isuser‐friendlycomputersoftwareforunivariatemapping(UVM)[29]andmultivariatemapping(MVM)[30]ofQTLwithepistasiseffectsandQEinteractioneffectsinDH,RI,BC,F2,IF2andBxFypopulations;andforgraphicalpresentationofQTLmappingresults.ThesoftwareisprogrammedbyC++programminglanguageunderMicrosoftVisualC++6.0environment.ItworkswithMicrosoftWindowsoperatingsystems,includingWindows95/98,NT,2000,XP,2008Server.Availability:http://ibi.zju.edu.cn/software/qtlnetwork/download.htm.

2.2 SoftwaresforGWASandtheirapplicationsThereareseveralsoftwaresavailableforGWAS.InthissectionwehavedescribedsomepopularsoftwaresandourdevelopedQTXNetworksoftwareandtheirapplicationsinGWAS.2.2.1 PLINK Itisthemostpopulartoolset(anopensourceC/C++WGAStoolset)forGWASandpopulationbasedlinkageanalysis,whichhasfivedomainfunctionsatelementaryversioni.e.datamanagement,summarystatistics,populationstratification,associationanalysis,andidentity‐by‐descentestimation[54].Latestversion(v1.7)includesmanyfunctionswithpreviousdomainfunctionsandpermitsmorecomplexanalysisthanearlierversions.Somemajorimplementedfunctionsaremetaanalysis:automaticallycombineseveralgenerically‐formattedsummaryfilesformillionsofSNPs,analysiswithfixedandrandomeffectsmodels;gene‐basedtestsofassociations,screenforepistasis,gene‐environmentinteractionwithcontinuousanddichotomousenvironments;multimarkerpredictorandhaplotypictests:conditionalhaplotypetests,case/controlandTDTassociationonprobabilistichaplotypephase,asetofproxyassociationmethodstostudysingleSNPassociationsintheirlocalhaplotypiccontext,imputationheuristic;copynumberofvariantanalysis:jointSNPandCNVtests,case/controlcomparisontestsforglobalCNVproperties,permutationbasedassociationprocedure;summarystatisticsforqualitycontrol:HWEtests,missinggenotyperates,IBSandIBDstatistics,non‐Mendeliantransmissioninfamilydata,sexchecksbasedonXchromosomeSNPs,testsofnon‐randomgenotypingfailure;andbasicassociationtesting:case/control(standardallelictest,Fisher sexacttests,Cochran‐Armitagetrendtestetc.),family‐basedassociation(TTD,sibshiptest),quantitativetraits,associationandinteraction,associationconditionalononeormoreSNPs.Availability:http://pngu.mgh.harvard.edu/purcell/plink/.

2.2.2 TASSEL Itisanotherpopularsoftwareforassociationmappingofcomplextraits,implementsQ+Kcompositeapproach,canmergedatafromdifferentsourcesintoasingleanalysisdataset,imputesmissingdatausingaK‐nearest‐neighboralgorithmandconductPCAtoreduceasetofcorrelatedphenotypes[55].Italsoprovidesassociationmappingwithgenerallinearmodel

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(GLM)andhaveabilitytohandleawiderangeofindels(insertionanddeletions).Exampledatasetsandtutorialdocumentarefreelyavailableathttp://www.maizegenetics.net/tasselandthesourcecodeforTASSELcanbefoundathttp://sourceforge.net/projects/tassel.

2.2.3 SNPassoc ItisanRpackageforGWAS,implementsfunctionsfordescriptivestatisticsandexploratoryanalysisofmissingvalues,calculationofHardy‐Weinbergequilibrium,analysisofassociationbasedongeneralizedlinearmodels(eitherforquantitativeorbinarytraits),andanalysisofmultipleSNPs(haplotypeandepistasisanalysis)[56].Permutationtest,sumstatisticandtruncatedproducttest,andmax‐statisticandgeneticrisk‐allelescoreexactdistributionsarealsoavailableinversion1.9‐1.Availability:http://cran.r‐project.org/web/packages/SNPassoc/index.html.

2.2.4 GenABEL AnRpackage,provideseasyinterfacestostandardstatisticalandgraphicalproceduresimplementedinbaseRandspecialRlibrariesforgeneticanalysis,providessummarystatisticsforphenotypicdataandchecksforoutliersataspecifiedP‐valueorfalsediscoveryratecut‐offlevel[57].Availability:http://cran.r‐project.org.

2.2.5 ProbABEL ImplementedcodesarewritteninCandC++languagesandconsistofthreeexecutablefiles,andareusedtoperformlinear,logistic,andCoxregressions,andahelperPerlscriptwhichfacilitatestheanalysisofmultiplechromosomes[58].Version0.4.1alsoincludesrobustvariance‐covariancematrixofparameterestimates,two‐stepscoretestforassociationandestimationofthekinshipmatrix.Availability:http://www.genabel.org/packages/ProbABEL.2.2.6 QTXNetwork AGPUparallelcomputingsoftware,canbeusedunderdifferentoperatingsystems(Windows,Unix,Mac).ThissoftwareusesGPUcomputationtechnologyandcandetectgene‐to‐geneinteractionandgene‐to‐environmentinteractionbyGWASofquantitativetraitwithSNPs(QTSs),transcripts(QTTs),proteins(QTPs),andmetabolites(QTMs);canincludecofactors(i.e.block,sex,age),geneticmaineffects(additiveA,dominanceD),epistasiseffects(additivebyadditiveAA,additivebydominanceAD,dominancebydominanceDD),andgene‐to‐environmentinteraction(AE,DE,AAE,ADE,andDDE);canestimatesuperiorgenotypes(positiveandnegative)ingeneralandaswellasindifferentenvironmentsandheritabilityforindividualeffects.Availability:http://ibi.zju.edu.cn/software/QTXNetwork.

3 Conclusions

Genome‐wideassociationstudies(GWAS)areadventasanexcellentcomplementtoQTLmapping,havebeenbecomingincreasinglypopularingeneticresearch.ItischallengingtoseparatemanylinkedgenethatcontainQTL,whereGWASproducemanyunlinkedindividualgenesorevennucleotides.However,thesestudiesmayriddlewithlargeexpectednumbersoffalsepositivesduetoinadequatestatisticalmethodologyanduseofsimplegeneticmodel.ImplementedmethodologyinQTXNetworksoftwarepermitstousemorecomplexgeneticmodel,basedonmixedmodelapproachthatiswidelyrecognizedforGWAS,andisabletoexplainmoreaboutgeneticarchitectureoftraitsanddiseasesascomparedtoexistingsoftware.Again,QTLNetworkprovidesmorefeatures,inwhichimplementedmethodologydoesnotrelyonnumberofmarkerslikeCIMandMCIM,providesunivariatemapping(UVM)aswellasmultivariatemapping(MVM)approaches,andpermitsmorecomplexmodelascomparedtoexistingsoftwareforQTLanalysis.

References:

[1] DoergeRW.Mappingandanalysisofquantitativetraitlociinexperimentalpopulations.NatureReviewsGenetics,2002,3

(1):43‐52.

[2] MottR,TalbotCJ,TurriMG,etal.Amethodforfinemappingquantitativetraitlociinoutbredanimalstocks.

ProceedingsoftheNationalAcademyofSciencesofthe

UnitedStatesofAmerica,2000,97(23):12649‐12654.

483第40卷 

马蒙,朱军:数量性状位点定位和全基因组关联分析的方法与软件综述(英文)

[3] LonghiS,MorettoM,ViolaR,etal.ComprehensiveQTLmappingsurveydissectsthecomplexfruittexturephysiology

inapple(Malus×domesticaBorkh.).Journalof

ExperimentalBotany,2012,63(3):1107‐1121.[4] WurschumT.MappingQTLforagronomictraitsinbreedingpopulations.TheoreticalandAppliedGenetics,2012,125

(2):201‐210.

[5] QuZ,LiLZ,LuoJY,etal.QTLmappingofcombiningabilityandheterosisofagronomictraitsinricebackcross

recombinantinbredlinesandhybridcrosses.PLoSONE,

2012,7(1):e28463.

[6] KimSM,SuhJP,LeeCK,etal.QTLmappinganddevelopmentofcandidategene‐derivedDNAmarkersassociated

withseedlingcoldtoleranceinrice(OryzasativaL.).Molecular

GeneticsandGenomics,2014,289(3):333‐343.[7] XuYF,WangRF,TongYP,etal.MappingQTLsforyieldandnitrogen‐relatedtraitsinwheat:influenceof

nitrogenandphosphorusfertilizationonQTLexpression.

TheoreticalandAppliedGenetics,2014,127(1):59‐72.[8] RosarioMF,GazaffiR,MouraA,etal.CompositeintervalmappingandmixedmodelsrevealQTLassociatedwith

performanceandcarcasstraitsonchickenchromosomes1,3,

and4.JournalofAppliedGenetics,2014,55(1):97‐103.[9] KorteA,FarlowA.TheadvantagesandlimitationsoftraitanalysiswithGWAS:areview.PlantMethods,2013,9

(1):29.

[10] YangJ,ZaitlenNA,GoddardME,etal.Advantagesandpitfallsintheapplicationofmixed‐modelassociation

methods.NatureGenetics,2014,46(2):100‐106.[11] NishizawaD,FukudaK,KasaiS,etal.Genome‐wideassociationstudyidentifiesapotentlocusassociatedwith

humanopioidsensitivity.MolecularPsychiatry,2014,19

(1):55‐62.

[12] ZillerMJ,GuH,MüllerF,etal.ChartingadynamicDNAmethylationlandscapeofthehumangenome.Nature,2013,

500(7463):477‐481.

[13] YangJ,FerreiraT,MorrisAP,etal.Conditionalandjointmultiple‐SNPanalysisofGWASsummarystatisticsidentifies

additionalvariantsinfluencingcomplextraits.Nature

Genetics,2014,44(4):369‐375.

[14] ManolioTA.Genomewideassociationstudiesandassessmentoftheriskofdisease.TheNewEnglandJournal

ofMedicine,2010,363(2):166‐176.

[15] WaterhouseEG,XuB.Theskinnyonbrain‐derivedneurotrophicfactor:evidencefromanimalmodelstoGWAS.

JournalofMolecularMedicine,2013,91(11):1241‐1247.[16] MeyerRS,PuruggananMD.Evolutionofcropspecies:geneticsofdomesticationanddiversification.NatureReviews

Genetics,2013,14(12):840‐852.

[17] LiH,PengZY,YangXH,etal.Genome‐wideassociationstudydissectsthegeneticarchitectureofoilbiosynthesisin

maizekernels.NatureGenetics,2013,45(1):43‐50.[18] AbrashE.Foodforthoughtfromplantandanimalgenomes.GenomeBiology,2013,14:302.

[19] HuangXH,KurataN,WeiXH,etal.Amapofricegenomevariationrevealstheoriginofcultivatedrice.

Nature,2012,490(7421):497‐501.

[20] HuangXH,HanB.Acropofmaizevariants.NatureGenetics,2012,44(7):734‐735.

[21] BucklerES,HollandJB,BradburyPJ,etal.Thegeneticarchitectureofmaizefloweringtime.Science,2009,325

(5941):714‐718.

[22] MammadovJ,AggarwalR,BuyyarapuR,etal.SNPmarkersandtheirimpactonplantbreeding.International

JournalofPlantGenomics,2012,2012:728398.

[23] LanderES,BotsteinD.MappingMendelianfactorsunderlyingquantitativetraitsusingRFLPlinkagemaps.

Genetics,1989,121(1):185‐199.

[24] ZengZB.Theoreticalbasisforseparationofmultiplelinkedgeneeffectsinmappingquantitativetraitloci.Proceedingsof

theNationalAcademyofSciencesoftheUnitedStatesof

America,1993,90(23):10972‐10976.

[25] ZengZB.Precisionmappingofquantitativetraitloci.Genetics,1994,136(4):1457‐1468.

[26] JansenRC,StamP.Highresolutionofquantitativetraitsintomultiplelociviaintervalmapping.Genetics,1994,136

(4):1447‐1455.

[27] KaoCH,ZengZB,TeasdaleRD.Multipleintervalmappingforquantitativetraitloci.Genetics,1999,152(3):

1203‐1216.

[28] WangDL,ZhuJ,LiZK,etal.MappingQTLswithepistaticeffectsandQTL×environmentinteractionsbymixed

linearmodelapproaches.TheoreticalandAppliedGenetics,

1999,99(7/8):1255‐1264.

[29] YangJ,ZhuJ,WilliamsRW.Mappingthegeneticarchitectureofcomplextraitsinexperimentalpopulations.

Bioinformatics,2007,23(12):1527‐1536.

[30] ZhuZH,ZhangCH,WangXS,etal.Dissectinganxiety‐relatedQTLsinmicebyunivariateandmultivariatemapping.

ChineseScienceBulletin,2012,57(21):2727‐2732.[31] KleinRJ,ZeissC,ChewEY,etal.ComplementfactorHpolymorphisminage‐relatedmaculardegeneration.Science,

2005,308(5720):385‐389.

[32] YuJ,PressoirG,BriggsWH,etal.Aunifiedmixed‐modelmethodforassociationmappingthataccountsformultiple

levelsofrelatedness.NatureGenetics,2006,38(2):

203‐208.

[33] MarchiniJ,HowieB,MyersS,etal.Anewmultipointmethodforgenome‐wideassociationstudiesbyimputationof

genotypes.NatureGenetics,2007,39(7):906‐913.[34] AulchenkoYS,deKoningDJ,HaleyC.Genomewiderapidassociationusingmixedmodelandregression:afastand

simplemethodforgenomewidepedigree‐basedquantitative

traitlociassociationanalysis.Genetics,2007,177(1):

583

 第4期

浙江大学学报(农业与生命科学版)

577‐585.

[35] KangHM,ZaitlenNA,WadeCM,etal.Efficientcontrolofpopulationstructureinmodelorganismassociation

mapping.Genetics,2008,178(3):1709‐1723.

[36] KangHM,SulJH,ServiceSK,etal.Variancecomponentmodeltoaccountforsamplestructureingenome‐wide

associationstudies.NatureGenetics,2010,42(4):348‐354.[37] ZhangZ,ErsozE,LaiCQ,etal.Mixedlinearmodelapproachadaptedforgenome‐wideassociationstudies.

NatureGenetics,2010,42(4):355‐360.

[38] WuMC,KraftP,EpsteinMP,etal.PowerfulSNP‐setanalysisforcase‐controlgenome‐wideassociationstudies.AmericanJournal

ofHumanGenetics,2010,86(6):929‐942.

[39] LippertC,ListgartenJ,LiuY,etal.FaSTlinearmixedmodelsforgenome‐wideassociationstudies.Nature

Methods,2011,8(10):833‐835.

[40] LüHY,LiuXF,WeiSP,etal.Epistaticassociationmappinginhomozygouscropcultivars.PLoSONE,2011,6

(3):e17773.

[41] SeguraV,VilhjálmssonBJ,PlattA,etal.Anefficientmulti‐locusmixed‐modelapproachforgenome‐wide

associationstudiesinstructuredpopulations.Nature

Genetics,2012,44(7):825‐830.

[42] ZhouX,StephensM.Genome‐wideefficientmixed‐modelanalysisforassociationstudies.NatureGenetics,2012,44

(7):821‐824.

[43] SvishchevaGR,AxenovichTI,BelonogovaNM,etal.Rapidvariancecomponents‐basedmethodforwhole‐genome

associationanalysis.NatureGenetics,2012,44(10):

1166‐1170.

[44] ZukO,HechterE,SunyaevSR,etal.Themysteryofmissingheritability:Geneticinteractionscreatephantom

heritability.ProceedingsoftheNationalAcademyof

SciencesoftheUnitedStatesofAmerica,2012,109(4):

1193‐1198.

[45] BrachiB,MorrisGP,BorevitzJO.Genome‐wideassociationstudiesinplants:Themissingheritabilityisinthe

field.GenomeBiology,2011,12(10):232.

[46] vanOsJ,RuttenB.Gene‐environment‐wideinteraction

studiesinpsychiatry.TheAmericanJournalofPsychiatry,

2009,166(9):964‐966.

[47] PhillipsPC.Epistasis:theessentialroleofgeneinteractionsinthestructureandevolutionofgeneticsystems.Nature

ReviewsGenetics,2008,9(11):855‐867.

[48] Carlborg湣,HaleyCS.Epistasis:toooftenneglectedincomplextraitstudies?NatureReviewsGenetics,2004,5(8):

618‐625.

[49] MackayTFC.Epistasisandquantitativetraits:usingmodelorganismstostudygene‐geneinteractions.NatureReviews

Genetics,2013,15(1):22‐33.

[50] SeatonG,HaleyCS,KnottSA,etal.QTLExpress:mappingquantitativetraitlociinsimpleandcomplex

pedigrees.Bioinformatics,2002,18(2):339‐340.[51] ManlyKF,CudmoreJrRH,MeerJM.MapManagerQTX,cross‐platformsoftwareforgeneticmapping.

MammalianGenome,2001,12(12):930‐932.

[52] BromanKW,WuH,SenS',etal.R/qtl:QTLmappinginexperimentalcrosses.Bioinformatics,2003,19(7):889‐890.[53] YangJ,HuCC,HuH,etal.QTLNetwork:mappingandvisualizinggeneticarchitectureofcomplextraitsin

experimentalpopulations.Bioinformatics,2008,24(5):

721‐723.

[54] PurcellS,NealeB,Todd‐BrownK,etal.PLINK:atoolsetforwhole‐genomeassociationandpopulation‐basedlinkage

analyses.AmericanJournalofHumanGenetics,2007,81

(3):559‐575.

[55] BradburyPJ,ZhangZ,KroonDE,etal.TASSEL:softwareforassociationmappingofcomplextraitsindiverse

samples.Bioinformatics,2007,23(19):2633‐2635.[56] GonzálezJR,ArmengolL,SoléX,etal.SNPassoc:anRpackagetoperformwholegenomeassociationstudies.

Bioinformatics,2007,23(5):644‐645.

[57] AulchenkoYS,RipkeS,IsaacsA,etal.GenABEL:anRlibraryforgenome‐wideassociationanalysis.Bioinformatics,

2007,23(10):1294‐1296.

[58] AulchenkoYS,StruchalinMV,vanDuijnCM.ProbABELpackageforgenome‐wideassociationanalysisofimputed

data.BMCBioinformatics,2010,11:134.

683第40卷 

数量性状位点定位和全基因组关联分析的方法与软件综述

(英文)

作者:马蒙, 朱军, Md Mamun Monir, Zhu Jun

作者单位:马蒙,Md Mamun Monir(浙江大学农业与生物技术学院农学系,杭州,310058), 朱军,Zhu Jun(浙江大学农业与生物技术学院农学系,杭州 310058; 浙江大学数学系,杭州 310058;

浙江大学空气污染与健康研究中心,杭州310058)

刊名:

浙江大学学报(农业与生命科学版)

英文刊名:Journal of Zhejiang University (Agriculture & Life Sciences)

年,卷(期):2014(4)

本文链接:https://www.360docs.net/doc/7d17449362.html,/Periodical_zjdxxb-nyysm201404003.aspx

刘祖洞遗传学第三版答案 第9章 数量性状遗传

第九章数量性状遗传 1.数量性状在遗传上有些什么特点?在实践上有什么特点?数量性状遗传和质量性状 遗传有什么主要区别? 解析:结合数量性状的概念和特征以及多基因假说来回答。 参考答案: 数量性状在遗传上的特点: (1)数量性状受多基因支配 (2)这些基因对表型影响小,相互独立,但以积累的方式影响相同的表型。 (3)每对基因常表现为不完全显性,按孟德尔法则分离。 数量性状在实践上的特点: (1)数量性状的变异是连续的,比较容易受环境条件的影响而发生变异。 (2)两个纯合亲本杂交,F1表现型一般呈现双亲的中间型,但有时可能倾向于其中的 一个亲本。F2的表现型平均值大体上与F1相近,但变异幅度远远超过F1。F2分离群体内,各种不同的表现型之间,没有显着的差别,因而不能得出简单的比例,因此只能用统计方法分析。 (3)有可能出现超亲遗传。 数量性状遗传和质量性状遗传的主要区别: (1)数量性状是表现连续变异的性状,而质量性状是表现不连续变异的性状; (2)数量性状的遗传方式要比质量性状的遗传方式复杂的多,它是由许多基因控制的,而且它们的表现容易受环境条件变化的影响。 2.什么叫遗传率?广义遗传率?狭义遗传率?平均显性程度? 解析:根据定义回答就可以了。 参考答案:遗传率指亲代传递其遗传特性的能力,是用来测量一个群体内某一性状由遗 传因素引起的变异在表现型变异中所占的百分率,即:遗传方差/总方差的比值。广义遗传 率是指表型方差(Vp)中遗传方差(Ve)所占的比率。狭义遗传率是指表型方差(Vp )中加性方差(V A)所占的比率。平均显性程度是指..V D /V A。〔在数量性状的遗传分析中,对于单位点模型,可以用显性效应和加性效应的比值d/a来表示显性程度。但是推广到多基因

文献综述 英文

文献综述 大学生时间管理研究——以郑州大学西亚斯国际学院为例 姓名:代永寒学号:20091211205 专业:工商管理班级:工本2班 史蒂芬?柯维的《要事第一》 “要事第一”,顾名思义是指重要的主要的事情要放在第一时间去完成。而在实际工作中我们往往是将认为急迫的紧要的事情放在第一时间完成; 本书通过四个象限来告诉我们如何区分事情的紧急性与重要性,从而告诉我们在平常的工作中应怎样去区分事情属轻属重,以及造成事情紧急性的原因,在平常工作中要注意哪些方面以避免出现紧急事件的情况。 第一象限包括四点:A危机 B 急迫的问题C最后期限迫近的项目 D 会议准备工作等。第一象限显得紧迫与重要,但我们要知道形成第一象限的紧迫与重要主要是因被延误及没有进行计划与预测及计划所致。第二象限包含准备工作、预防、价值、筹划、建立关系、真正的再创造与赋予能力。第二象限属于质量象限,属于重要但不紧迫的事情,但我们必须要去做,因只有这样才能避免出现第一象限包含的情况。第三象限包含干扰、电话;邮件、报告;某些会议;很多临近、急迫的事情及很多流行的活动。第三象限包括“紧急但不重要的事情”,而事实上它易给人造成假象,从而形成第一象限情况。第四象限包含琐事、打发时间的工作、某些电话,解闷,“逃避”行为、无关紧要的邮件及过多地看电视;第四象限属于既不紧急也不重要的事情,它是浪费象限,第四象限中的行为是堕落行为。这四个象限告诉我们如果在办事过程中不是以重要性而是以紧要性为出发点,就会出现第一第三甚至第四象限的情况,在平常的工作中,我们要加以区分,日常工作生活中往往事情越是紧迫,反而说明事情越不重要!像最近存货系统因急着想能早日上线,在运作过程中被卡住,故一心想着去解决软件中存在的问题,而忽略了与其他人员的沟通协调,存货上软件固然重要,但与公司整体运作相比就稍显其次,没合理分配其他人员手头事项,这样会导致其他问题的增多,从而会出现第一第三象限甚至于第四象限的浪费情况。 “要事第一”,告诉我们在日常的工作与生活中要从以下方面着手加以区分、

数量性状基因座原理

数量性状基因座(QTL)定位的基本原理 数量性状基因座(quantitative trait locus,QTL)指的是控制数量性状的基因在基因组中的位置。QTL定位的理论依据是Morgan 的连锁遗传规律,通过数量性状观察值与标记间的关联分析,当标记与特定性状连锁时,不同标记基因型个体的表型值存在显著差异,来确定影响各个数量性状的基因(QTL)在染色体上的位置、效应,甚至各个QTL间的相关作用。QTL定位检测的是分子标记与QTL之间的连锁关系,通过分析整个染色体组的DNA标记和数量性状表型值的关系,将QTL逐一的定位到连锁群的相应位置,并估算出相应的QTL效应值。QTL定位实质上是基于一个特定模型的遗传假设,与数量性状基因有本质区别,是统计学上的一个概念,有可信度(如95%、99%等)。 近年来,数量性状的研究进入了崭新的QTL时代,先后提出了多种QTL定位的统计方法。可分两大类:一类是基于性状的分析方法(Trait Based Analysis,TBA),其原理是利用分离群体的两极端表型个体来分析标记与QTL的连锁关系,检验标记基因型在两极端类型内的分离比是否偏离孟德尔定律;第二类是基于标记的分析方法(Marker Based Analysis,MBA),如果某标记与QTL连锁,该标记与QTL在一定程度上共分离,分析不同标记基因型的表型值差异来推测标记与QTL的连锁关系。MBA方法通常有3类,即传统的单标记分析法(Single Marker Analysis,SMA)、性状-标记回归法和性状- QTL - 回归法。性状- QTL - 回归法又包括基于两个侧邻标记的区间作图法

全基因组关联分析的原理和方法

全基因组关联分析(Genome-wide association study;GWAS)是应用基因组中 数以百万计的单核苷酸多态性(single nucleotide ploymorphism ,SNP)为分子 遗传标记,进行全基因组水平上的对照分析或相关性分析,通过比较发现影响复杂性状的基因变异的一种新策略。 随着基因组学研究以及基因芯片技术的发展,人们已通过GWAS方法发现并鉴定了大量与复杂性状相关联的遗传变异。近年来,这种方法在农业动物重要经济性状主效基因的筛查和鉴定中得到了应用。 全基因组关联方法首先在人类医学领域的研究中得到了极大的重视和应用,尤其是其在复杂疾病研究领域中的应用,使许多重要的复杂疾病的研究取得了突破性进展,因而,全基因组关联分析研究方法的设计原理得到重视。 人类的疾病分为单基因疾病和复杂性疾病。单基因疾病是指由于单个基因的突变导致的疾病,通过家系连锁分析的定位克隆方法,人们已发现了囊性纤维化、亨廷顿病等大量单基因疾病的致病基因,这些单基因的突变改变了相应的编码蛋白氨基酸序列或者产量,从而产生了符合孟德尔遗传方式的疾病表型。复杂性疾病是指由于遗传和环境因素的共同作用引起的疾病。目前已经鉴定出的与人类复杂性疾病相关联的SNP位点有439 个。全基因组关联分析技术的重大革新及其应用,极大地推动了基因组医学的发展。(2005年, Science 杂志首次报道了年龄相关性视网膜黄斑变性GWAS结果,在医学界和遗传学界引起了极大的轰动, 此后一系列GWAS陆续展开。2006 年, 波士顿大学医学院联合哈佛大学等多个研究机构报道了基于佛明翰心脏研究样本关于肥胖的GWAS结果(Herbert 等. 2006);2007 年, Saxena 等多个研究组联合报道了与2 型糖尿病( T2D ) 关联的多个位点, Samani 等则发表了冠心病GWAS结果( Samani 等. 2007); 2008 年, Barrett 等通过GWAS发现了30 个与克罗恩病( Crohns ' disrease) 相关的易感位点; 2009 年, W e is s 等通过GWAS发现了与具有高度遗传性的神经发育疾病——自闭症关联的染色体区域。我国学者则通过对12 000 多名汉族系统性红斑狼疮患者以及健康对照者的GWAS发现了5 个红斑狼疮易感基因, 并确定了4 个新的易感位点( Han 等. 2009) 。截至2009 年10 月, 已经陆续报道了关于人类身高、体重、 血压等主要性状, 以及视网膜黄斑、乳腺癌、前列腺癌、白血病、冠心病、肥胖症、糖尿病、精神分 裂症、风湿性关节炎等几十种威胁人类健康的常见疾病的GWAS结果, 累计发表了近万篇 论文, 确定了一系列疾病发病的致病基因、相关基因、易感区域和SNP变异。) 标记基因的选择: 1)Hap Map是展示人类常见遗传变异的一个图谱, 第1 阶段完成后提供了 4 个人类种族[ Yoruban ,Northern and Western European , and Asian ( Chinese and Japanese) ] 共269 个个体基因组, 超过100 万个SNP( 约1

QTL-seq:用重测序方法进行数量性状基因座(QTL)定位的方法

TECHNICAL ADVANCE/RESOURCE QTL-seq:rapid mapping of quantitative trait loci in rice by whole genome resequencing of DNA from two bulked populations Hiroki Takagi 1,2,Akira Abe 2,3,Kentaro Yoshida 1,Shunichi Kosugi 1,Satoshi Natsume 1,Chikako Mitsuoka 1,Aiko Uemura 1,Hiroe Utsushi 1,Muluneh Tamiru 1,Shohei Takuno 4,Hideki Innan 5,Liliana M.Cano 6,Sophien Kamoun 6and Ryohei Terauchi 1,*1 Iwate Biotechnology Research Center,Kitakami,Iwate,024-0003,Japan,2 United Graduate School of Iwate University,Morioka,Iwate,020-8550,Japan,3 Iwate Agricultural Research Center,Kitakami,Iwate,024-0003,Japan,4 Department of Plant Sciences,University of California,Davis,CA 95616,USA,5 Graduate University for Advanced Studies,Hayama,Japan,and 6 The Sainsbury Laboratory,Norwich Research Park,Norwich,UK Received 7September 2012;revised 13December 2012;accepted 20December 2012;published online 05January 2013.*For correspondence (e-mail terauchi@ibrc.or.jp). SUMMARY The majority of agronomically important crop traits are quantitative,meaning that they are controlled by multiple genes each with a small effect (quantitative trait loci,QTLs).Mapping and isolation of QTLs is important for ef?cient crop breeding by marker-assisted selection (MAS)and for a better understanding of the molecular mechanisms underlying the traits.However,since it requires the development and selection of DNA markers for linkage analysis,QTL analysis has been time-consuming and labor-intensive.Here we report the rapid identi?cation of plant QTLs by whole-genome resequencing of DNAs from two populations each composed of 20–50individuals showing extreme opposite trait values for a given phenotype in a segregating progeny.We propose to name this approach QTL-seq as applied to plant species.We applied QTL-seq to rice recombinant inbred lines and F 2populations and successfully identi?ed QTLs for important agronomic traits,such as partial resistance to the fungal rice blast disease and seedling vigor.Simulation study showed that QTL-seq is able to detect QTLs over wide ranges of experimental variables,and the method can be generally applied in population genomics studies to rapidly identify genomic regions that underwent arti?cial or natural selective sweeps. Keywords:quantitative trait loci,breeding,whole genome sequencing,next generation sequencer,selective sweep,technical advance. INTRODUCTION The world’s population has already exceeded 7billion and is still growing,while the amount of land suitable for agri-culture is decreasing due to a variety of factors such as rapid climate change.Therefore there is a great demand for ef?cient crop improvement to increase yield without further expanding farmland and damaging the environ-ment (Godfray,2010;David et al.,2011). In crop plants,multiple genes each with a relatively minor effect control the majority of agronomically impor-tant traits.These genes are called quantitative trait loci (QTLs)(Falconer and Mackay,1996).Identi?cation of QTLs is an important task in plant breeding.Once a QTL control-ling a favorable trait is mapped with closely linked DNA markers,it is introduced into an elite cultivar by crossing of the recurrent elite parent to the donor plant.Following QTL a process marker-assisted selection and Matsuoka,2006).Marker-assisted selection reduces the effort and time needed for phenotype evaluation of the progeny during successive improves introgression ?2013The Authors The Plant Journal ?2013Blackwell Publishing Ltd 174 The Plant Journal (2013)74,174–183doi:10.1111/tpj.12105

第四章数量性状的遗传

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文献综述英文版

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