郝柏林院士的生物信息学讲座

FindingGenesintheRiceGenome,HaoBailinT-LifeResearchCenter,FudanUniversityBeijingGenomicsInstitute,AcademiaSinicaInstituteofTheoreticalPhysics,AcademiaSinica(,TwoCultivarsofRice,Oryzasativassp.indica(籼稻)Oryzasativassp.Japonica(粳稻)ThedifferencewasdescribedinXuShens(许慎说文解字)ChineseDictionaryofEastHanDynasty(2ndCenturyAD)J.H.Zhangetal.RicecultivationofJianhuRemainsinHenanProvince,ScienceJ.(科学杂志)，53（4），2002，3(inChinese),cccaatatcttgcttcagcaagatattgggtatttctagctttcctttcttcaaaaattgctatatgttagcagaaaagccttatccattaagagatggaacttcaagagcagctaggtctagagggaagttgtgagcattacgttcgtgcattacttccataccaagattagcacggttgatgatatcagcccaagtattaataacgcgaccttggctatcaactacagattggttgaaattgaatccgtttagattgaaagccatagtactaatacctaaagcagtgaaccaaatccctactacaggccaagcagccaagaagaagtgtaaagaacgagagttgttaaaactagcatattggaagattaatcggccaaaataaccatgagcggccacaatattataagtttcttcctcttgaccaaatctgtaaccctcattagcagattcgttttcagtggtttccctgatcaaactagaggttaccaaggaaccatgcatagcactgaatagggaaccgccgaatacaccagctacacctaacatgtgaaatggatgcataaggatgttatgctctgcctggaatacaatcataaagttgaaagtaccagatattcctaaaggcataccatcagagaaacttccttgaccaatagggtaaatcaagaaaacagcagtagcagctgcaacaggagctgaatatgcaacagcaatccaaggacgcatacccagacggaaactcagttcccactcacgacccatataacaagctacaccaagtaagaagtgtagaacaattagctcataaggaccaccattgtataaccactcatcaacagatgcagcttcccaaattgggtaaaagtgcaatccgatcgccgcagaagtaggaataatggcaccagagataatattgtttccgtaaagtaaagaaccagaaacaggctcacgaataccatcaatatctactggaggggcagcgatgaaggcgataataaatacagaagttgcggtcaataaggtagggatcatcaaaacaccgaaccatccgatgtaaagacggttttcggtgctagttatccagttgcagaagcgaccccacaggcttgtactttcgcgtctctctaaaattgcagtcatggtaagatcttggtttattcaaattgcaaggactcccaagcacacgtattaactagaaagataatagaaggcttgttatttaacagtataatatagactatataccaatgtcaaccaagccagccccgacagttgtatatccatacaacaaaatttaccaaaccaaaaaattttgtaaatgaagtgagtgaaaaatcaaaactcagattgctcctttctagtttccatatgggttgcccgggactcgaacccggaactagtcggatggagtagataattattccttgttacaatagagaaaaaacctctccccaaatcgtgcttgcatttttcattgcacacgactttccctatgtagaaataggctatttctattccgaagaggaagtctactaatttttttagtagtaagttgattcacttactatttattatagtacagagaacatttcagaatggaaactgtgaaagttttaccttgatcatttatcaatcatttctagtttattagttttgtttaatgattaattaagaggattcaccagatcattgatacggagaatatccaaataccaaatacgctcactgtgcgatccacggaaagaaaagtaagttgttttggcgaacatcaaagaaaaaacttgctcttcttccgtaaaaaattcttctaaaaataccgaacccaaccattgcataaaagctcgtaccgtgcttttatgtttacgagctaaagttctagcgcatgaaagtcgaagtatatactttagtcgatacaaagtcttcttttttgaagatccactgtgataatgaaaaagatttctacatatccgaccaaaccgatcaagaatatcccaatccgataaatcggtccaaattggtttactaataggatgccccgatccagtacaaaattgggcttttgctaaagatccaatgagaggagtaacagggactttggtatcgaattttttcatttgagtatctattagaaatgaattctccagcatttgattccttactaacaaagaatttattggtacacttgaaaagtaccccagaaaatcgaagcaagagttttctaattggtttagatggatcctttgcggttgagtccaaaaagagaaagaatattgccacaaacggacaaggtaacatttccatttcttcttcaaaagaagagttccttttgatgcaagaattgcctttccttgatatcgaacataatgcataaggggatccataacgaaccatatggttttccgaaaaaaagcagggtacattaacccaaaatgttccatcttcctagaaaagatgattcgttccagaaaggttccggaagaagttaatcgcaagcaagaagattgtttacgaagaaacaacaagaaaaattcatattctgatacataagagttatataggaaccgaaatagtcttttattttcttttttcaaaataaaaatggatttcattgaagtaataaaactattccaattcgagtagtagttgagaaagaatcgcaataaatgcaaggatggaacatcttggatccggtattgaaggagttgaagcaagatatccaaatggataggatagggtatttctatatgtgctagataatgtaagtgcaaaaatttgtcttctaaaaaaggaaatattgaatgaatagatcgtaaattctgaaactttggtatttctttttcttccggacaagactgttctcgtagcgagaatgggatttctacaacgatcgcaaacccctcagatagaatctgagaataaaactcagaataaaaaaaattgttgtaatccaataatcgatcttggttaggatgattaaccaaattaatccaaaaattctgctgatacattcgaatcattaaccgtttcacaagtagtgaactaaatttcttgttattagaaccaataatttcgacaagttcggaaccatttaatccataatcatgggcaaacacataaatgtactcctgaaagagtagtgggtagacgaaatattgtctaggaaatttaagtttttctgaataaccctcgaatttttccatttgtatttctacttgaatcagagagagagaaatatttctcggtttatcaaatggtgatacatagtacaatatggtcagaacagggtgttgcattttttaatacaaacccctggggaagaaaaggagtctaatccacggatctttttccgctccttttctatccaatttgtttatgtttgttctaattacaaaagagaacaaatcctttatttttgcaggccaattgctcttttgactttgggatacagtctctttatcaatatactgcttcttttacacattcaatccataacatccttttcaatccaaaatcaagaataattaggatttctaaaaaaaaaagaaaaaatcaaaggtctactcataggaaaaccagcttttccctacatcaggcactaatctatttttaacgtctaattagatcagggagttcttccaattaagaagttaagctcgttgctttttgttttaccagaattggagccaggctctatccatttattcattagacccagaaaatcagaatttttttattccattccaaaaatccaaaataagaaattgattttattacgacatgctattttttccattcattacccttgaggatcagtcgcggtcttatagactctaccaagagtctggacgaattttttgcttcatccaaatgtgtaaaagatcatagtcgcacttaaaagccgagtactctaccattgagttagcaacccagataaactaggatcttagatacgatcgaaatccaaaaatcaatggaattacaccgcacacccctgtcaaaatcttaaaatagcaagacattaaaagaaagattttatcaccattgaaaacactcagataccaaaaggaacgggtctggttaaatttcactaaggttaaaagtggcaccaatcacgatcgtaaaattgtcatttttttagcatttttatttaaataaataaataaatcttgtatgagagtacaaacaagagggacaaccctaccatttgagcaaagtgtaggcaaaaaacctaatagggagtgaggataaagagacttatccatctacaaattctagatgttcaatggacctttgtcaatggaaatacaatggtaagaaaaaaattagatagaaaaactcaaaaaaataaaggcttatgttggattggcacgacataaatccagtcaaaaataggattaagaaagaggcaaattatttctaaatagttagacaacaagggatactagtgagcctctcctagttttttattcatttagttcttcaattaactcaaagttctttctttttctttaaagaattccgccttccttaaaatatcagaaacggttcttgtaggttgagcacctttttcaaggaaatagagaatagctggaacatttaaacaagtttgattctttatcggatcataaaaacctacttttcgaagatctcttccttctcttcgagatcgaacatcaattgcaacgattcgatagacagcttattgggatagatgtagataaataaagccccccctagaaacgtataggaggttttctcctcatacggctcgagaatatgacttgcattaatttccgtacagaaaaaacaaatttcatttatactcatgactcaagttgactaattttgattgacagacttgaaagaaaaaaatcctttgaaattttttgagtcgtctctaaactcttttctttgcctcatctcgaacaaattcacttttattccttattccggtccaattctattgttgagacagttgaaaatcgtgtttacttgttcgggaatcctttatctttgatttgtgaaatccttgggtttaaacattacttcgggaattcttattcttttttctttcaaaagagtagcaacatacccttttttcttatttccttcgataaagcatttccctcttctatagaaatcgaatatgagcgattgattctgatagactttaatcaaaagagttttcccatatcttccaaaattggactttcttcttattttaaccttttgatttctatattatttcgatttctatattaagggtagaatgacaaagttggcctaatttattagttttcactaaccctagattctttcccttgataaaaaataaattctgtcctctcgagctccatcgtgtactatttacttagcttacttacaaacaacccagcgaaaattcggttcgggacgaatagaacagactatgtcgagccaagagcattttcattactatggaaaatggtggatagcaaaatccacaatcgatcgtgtccttcaagtcgcacgttgctttctaccacatcgttttaaacgaagttttaacataacattcctctaatttcattgcaaagtgttatagggaattgatccaatatggatggaatcatgaatagtcattagtttcgttttttgtatactaattcaaacttgctttgctatctatggagaaatatgaataaaagaaattaagtatttatcgggaaagactccgcaaagagccaatttatttaaacccatattctatcatatgaatgaaatatagttcgaaaaaagggaataaacaagtttgcttaagacttatttattatggaatttccatcctcaacagaggactcgagatgatcaatccaatcctgaaatgataagagaagaattgactcttctccaacaaataaactatcaacctcccgtttaattaatttaattaatatattagattagcaatctatttttccataccatttttccgtaacaaaactaattaactattaactagttaaactattgcaatgaaaagaaagttttttggtagttatagaattctcgtatttcttcgactcgaataccaaaagaaagaaaaaaatgaagtaaaaaaaacgcatttcctgtaaagtaaaattaaggtctttgcttttacttattttttcttttacctaaaagaagcaactccaaatcaaaattgaatccattctatctaacgagcagttcttatcttatctttaccgggatggatcattctggatatttaaaaaatcgcggatcgagatcgtttttgcttaaccaaagaaagaaaaagaagaaggaaccttttttactaataaaatactataaaaaaaatttatctctatcataaatctatctctaccataaaggaataggtctcgttttttatacaatgttctacgtcaagtttaaaattttttcatgaaaaaaagattttcaatttgactggacttgacactggattatgttttctgagacagaaaatgaacgcattaggactgcatcgaatctaagagtttataagagaaaaaaattctctttaataaactttatgtctcgtgcagaatacaatacgatttcatctttcgtttcatcagaaaaaatctgggacggaaggattcgaacctccgagtaacgggaccaaaacccgctgccttaccacttggccacgccccatttcgggttttatgcgacactaataaacagtattatgtttatttcttattcgtcaatcctacttcaattacataaaaatggggggtattctcttggtaggattctagacatgcgaataatatagaatccaaaaaatgcattgatcattacatggaattctattaagatattatatgaaagtcgaatttcttccactctcatttgagagtgcgaatacaaggaggtattttgtgtttgggaaagtccgaagaaaaaaggattttgaatcctccttttcctttttcccttagaaaaataactcaatcaaaatccaattatctactctacaagaacgaaacgcttgttatgcctaatatacttagtttaacctgtatttgttttaattctgttatttatccgactagttttttcttcgccaaattgcccgaagcttatgccattttcaatccaatcgtggattttatgcctgtcatacctgtactcttttttctattagcctttgtttggcaagctgctgtaagttttcgatgaaatctttactactctgtctgccaaattgaatcatgtattcattctaaaaaaattcgaaaaatggataagagccgagaagtcttatattatgaaccttcgattctaaaattcaaattcttctacattgaatgtatagctgcagcaataaatttggatcagcctttctactccctgcatctacgttgagcaggtatctttaggtaaccgcacaatacctaacctaatttattgataagagtgcttattataaatcaattcttgcaatttttttcaaaaattgatttttgcatttttaggtgtcaaaataaacaaaacccatcctagtggatttgtgtggtaaggaaaaacgggtaatctattccttaaaaaaaaatcttggagattatgtaatgcttactctcaaactttttgtttatacagtagtgatattctttgtttccctctttatctttggattcttatctaatgatccaggacgtaatcctgggcgtgacgagtaaaaatccaaaattttttcttacaaattggatttgtttcatacatttatctacgagaaaatccgggggtcagaattccttccaattcgaaagtcccaaacgatccgagggggcggaaagagagggattcgaaccctcggtacaaaaaaattgtacaacggattagcaatccgccgctttagtccactcagccatctctccccgttccaaatcgaaaggtttccgtgatatgacagaggcaagaaataacgattgcaaaaaatccttcctttttctttcaaaagttcaaaaaaattatattgccaattccattttagttatattcttttttcttaatgttaataaaaaaaagaagaaaattcttcttttttctttctaattctaaaattggatattggctaaaagacaatcagatagattttctcttcagcaggcatttccatataggacttgttataataaaacaagcaggttatagaaaaaaactcttttttttattatttatcaacaaagcaaaaaggggtcttatcaaaccaacccaccccataaaattggaaagaaagataaagtaagtggacctgactccttgaatgaggcctctatccgctattctgatatataaattcgatgtagatgaaattgtataagtggatttttttgtatttccttagacttagaccacgcaaggcaagaatttctcgctatttactatttcatattcttgttactagatgttctataggaataagaagaaatcgcaacccctttccgctacacataaaaatggatttcgaaagtcaatttttcttttcaatatctttactttttttcagaatcctatttttgttcttatacccatgcaatagagagcgagtgggaaaagggaggttactttttttcattttttccttaaaaaataggctttcttggaaataggaatcatggaataatctgaattccaatgtttatttctatagtataagaaaaactaattgaatcaaattcatggatttaccacgacctcggctgtgaccccatagataaaaatgcaaaatttctatcttcgagaccattgaaaaaaggcattgaacgagaaaaaatcgtccacagataatctatcgtatgccttggaagtgatataaggtgctcggaaatggttgaagtaattgaataggaggatcactatgactatagcccttggtagagttactaaagaagaaaatgatttatttgatattatggacgactggttacgaagggaccgttttgtttttgtaggatggtctggcctattgctttttccttgtgcttatttcgctttaggaggttggtttacagggacaacttttgtaacttcttggtatacccatggattggcgagttcctatttggaaggttgcaatttcttaaccgcagcagtttccacccctgccaatagtttagcacactctttgttgctactatggggcccggaagcacaaggggattttactcgttggtgtcaattaggtggtctgtggacttttgttgctctccatggggcttttgcactaataggtttcatgttacgtcaatttgaacttgctcggtctgttcaattgcggccttataatgcaatttcattctctggcccaatcgctgtttttgtttccgtattcctgatttatccactggggcaatccggttggttctttgcgccgagttttggcgtagcagcgatatttcgattcatcctcttcttccaaggatttcataattggacgttgaacccatttcatatgatgggagttgccggagtattaggcgcggctctgctatgcgctattcatggggcaaccgtgga,Gene-FindingbyComputer,Startingfromearly1980s:“Abinitio”or“denovo”algorithms:GeneMark,GenScan,FgeneSH,Genie,basedongene-structuremodelsandtrainingdata.(Ouron-goingproject:BGF,theBGIGeneFinder)HomologmethodsbasedonsequencealignmentwithknowngenesindatabasesMixedapproachusingbothstrategy:TwinScan,DifferentStagesofGene-Finding,Useallpossibleexistingprogramsandservicesonthewebwithapublic-domainorhome-madegenomeviewerWriteyourowngene-finder,trainedforthespecificorganismAdreamforthetimebeing:designaself-trainingandself-developingprogram“foranyspecies”whichwouldimproveitselfiterativelystartingfromafewavailablereads,cDNAs,andESTs,PerformanceofGene-FindersinEukaryoteGenomes,M.Q.Zhang,NatureReviewGenetics,3(2002)698-710(mostlyforthehumangenome):Nucleotidelevel:80%Exonlevel:45%Wholegenestructure:20%FgeneSHandBGFforrice(ourtestson128cDNA-confirmedsingle-genegenomicsequences):Nucleotidelevel:90%Exonlevel:60%Wholegenestructure:40%,5,3,3,5,Eachstrandcarriesthesameamountofinformation,butdifferentsetsofgenes.Twostrandsareequivalentininformationcontent.Twostrandsarenotequivalentingenecontent.Biologicalprocessing(duplication,transcription)goesfrom5to3.Findinggenesononestrandatatimeorontwostrandsatthesametime:one-passortwo-passprograms.,5-UTR3-UTR,transcribe,GenomicDNA,Pre-mRNA,splice,mRNA,translate,AAseq(proteinprimaryseq),fold,Proteinfold,start,stop,5,3,RNAPolII+,splicesomeu1u2u4u5u6RNP,ribsomeinit.+elong.factorsterm.chaperonine,ThreeScalesofSearch,Local:signalswithminimalsignature(start,stop,splicing);movablesignals(caps,promoters,polyAs,branchingpoints,someveryweak)-clustering,discriminationanalysis,variousstatisticalmodelsIntermediate:exons,introns,intergenic-Markov,semi-Markov,Hidden-Markovmodels;intronlengthdistributionGlobal:optimalcombinationoftheabove-dynamicprogramming,（）【（.）（.）（.）】（）,Signals:transcriptionstart(downstreamofpromoters)transcriptionend(upstreamofpoly-A)【translationstart(ctg,1/64inarandomseq.)】translationend(tag,tga,taa,3/64)（splicingdonorsite(minimalsignal=gt,1/16)）splicingacceptersite(ag,1/16)branchingpoint(veryweaka),TranscriptionTranslationTranslationTranscriptionstartstartendend,（）【（.）（.）（.）】（）,【（Firstexon）（Internalexon）】Lastexon（Non-coding5exon）【Non-coding5exon（.）Intron】（Non-coding3exon(rare)）Non-coding3exon(rare)Intergenicregion,TranscriptionTranslationTranslationTranscriptionstartstartendend,SignalandSequenceModels,eiid:equalprobabilityindependentlyandidenticallydistributedniid:non-equalprobabilityindependentlyandidenticallydistributedWWM:Windowedweightmatrix,etc.MMn:Markovchainmodelofordern:homogeneousandperiod-3MM5areusedinmanygene-findersConsensussequence,ConsensusSequences,TATAAT(Pribnovor-10box):T80A95T45A60A50T96TTGACA(-35box):T82T84G78A65C54A45CAAT(CAATor75box):GGYCAATCTTATA(TATAorGoldberger-Hognessbox):TATAWAWATG(Transcriptionstartpoint)However,inAful:ATG76%GTG22%TTG2%,GT-AGRuleforIntron,5splicingdonorsiteexonA64G73G100T100A62A68G84T6312PyNC65A100G100Nexon3splicingacceptorsite,Exonandintronsizedistribution,Algorithms,SequencemodelsandscoresforsignalsDynamicprogramming:optimalparseHiddenMarkovModel:geometricdistributionofintronlengthsSemi-HiddenMarkovModel:needssequence-generatingmodelsandlengthprobabilityforeachnodeLanguagetheoryapproach,FlowChartofGenScan,ChrisBurge(1996):A27-statesemi-HMMAsimplermodel:19-stateAmodeltakingUTRintronsintoaccount：35-state,Figure：N,intergenicregion;P,promotor;F,5UTR;,single-exongene;,initialexon;phasekinternalexon;,ter-minalexon;T,3UTR;A,polyadenylationsignal;and,phasekintron.)strand.,Problems:MinorandMajor,Ambiguitysymbols(N,W,S,R,)(1-p)atflankingD-typenodesIndelsandframe-shiftsGradienteffectsingenestructureIntronsin5-UTRsand3-UTRs:leadingto35-stateMarkovModelsAlternativesplicingandsub-optimalpathsLimitofprobabilisticmodelsDeterministicapproaches,Dycklanguage:Alanguageofnestedparentheses,ManytypesofparenthesesFinitedepthofnestingContext-freelanguageOurcase:Only3typesofparenthesesShallownestingConjecture:mayberegularlanguage,TwoTestDatasetsforRiceGene-Finders,The28469japonicafull-lengthcDNAs(Kikuchietal.,Science301(18July2003)Selectahigh-qualitysubsetwithoutoverlapswithpublicallyavailablecDNAsAsingle-geneset:500sequenceswithonegeneineachAmulti-geneset:46