广州市XX大道一期工程施工课件

广州市番禺区番禺大道一期工程施工T。。。2023/7/26广州市番禺区番禺大道一期工程施工T。。。IntroductionUntiltheearly1970’s,DNAwasthemostdifficultcellularmoleculeforbiochemiststoanalyze.DNAisnowtheeasiestmoleculetoanalyze–wecannowisolateaspecificregionofthegenome,produceavirtuallyunlimitednumberofcopiesofit,anddetermineitsnucleotidesequenceovernight.MolecularBiologyOfTheCell.Albertsetal.491-495广州市番禺区番禺大道一期工程施工T。。。IntroductionAttheheightoftheHumanGenomeProject,sequencingfactoriesweregeneratingDNAsequencesatarateof1000nucleotidespersecond24/7.TechnicalbreakthroughsthatallowedtheHumanGenomeProjecttobecompletedhavehadanenormousimpactonallofbiology…..MolecularBiologyOfTheCell.Albertsetal.491-495广州市番禺区番禺大道一期工程施工T。。。HumanGenomeProjectGoals:

■identifyalltheapproximate30,000genesinhumanDNA,■determinethesequencesofthe3billionchemicalbasepairsthatmakeuphumanDNA,■storethisinformationindatabases,■improvetoolsfordataanalysis,■transferrelatedtechnologiestotheprivatesector,and■addresstheethical,legal,andsocialissues(ELSI)thatmayarisefromtheproject.

Milestones:■1990:ProjectinitiatedasjointeffortofU.S.DepartmentofEnergyandtheNationalInstitutesofHealth

■June2000:Completionofaworkingdraftoftheentirehumangenome(covers>90%ofthegenometoadepthof3-4xredundantsequence)■February2001:Analysesoftheworkingdraftarepublished■April2003:HGPsequencingiscompletedandProjectisdeclaredfinishedtwoyearsaheadofscheduleU.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003http://www.sanger.ac.uk/HGP/overview.shtml广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?

BytheNumbers•Thehumangenomecontains3billionchemicalnucleotidebases(A,C,T,andG).

•Theaveragegeneconsistsof3000bases,butsizesvarygreatly,withthelargestknownhumangenebeingdystrophinat2.4millionbases.

•Thetotalnumberofgenesisestimatedataround30,000--muchlowerthanpreviousestimatesof80,000to140,000.

•Almostall(99.9%)nucleotidebasesareexactlythesameinallpeople.

•Thefunctionsareunknownforover50%ofdiscoveredgenes.U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?HowIt'sArranged•Thehumangenome'sgene-dense"urbancenters"arepredominantlycomposedoftheDNAbuildingblocksGandC.

•Incontrast,thegene-poor"deserts"arerichintheDNAbuildingblocksAandT.GC-andAT-richregionsusuallycanbeseenthroughamicroscopeaslightanddarkbandsonchromosomes.

•Genesappeartobeconcentratedinrandomareasalongthegenome,withvastexpansesofnoncodingDNAbetween.

•Stretchesofupto30,000CandGbasesrepeatingoverandoveroftenoccuradjacenttogene-richareas,formingabarrierbetweenthegenesandthe"junkDNA."TheseCpGislandsarebelievedtohelpregulategeneactivity.

•Chromosome1hasthemostgenes(2968),andtheYchromosomehasthefewest(231).

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?

TheWheatfromtheChaff•Lessthan2%ofthegenomecodesforproteins.

•Repeatedsequencesthatdonotcodeforproteins("junkDNA")makeupatleast50%ofthehumangenome.

•Repetitivesequencesarethoughttohavenodirectfunctions,buttheyshedlightonchromosomestructureanddynamics.Overtime,theserepeatsreshapethegenomebyrearrangingit,creatingentirelynewgenes,andmodifyingandreshufflingexistinggenes.

•Thehumangenomehasamuchgreaterportion(50%)ofrepeatsequencesthanthemustardweed(11%),theworm(7%),andthefly(3%).U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?

HowtheHumanCompareswithOtherOrganisms

•Unlikethehuman'sseeminglyrandomdistributionofgene-richareas,manyotherorganisms'genomesaremoreuniform,withgenesevenlyspacedthroughout.

•HumanshaveonaveragethreetimesasmanykindsofproteinsastheflyorwormbecauseofmRNAtranscript"alternativesplicing"andchemicalmodificationstotheproteins.Thisprocesscanyielddifferentproteinproductsfromthesamegene.

•Humanssharemostofthesameproteinfamilieswithworms,flies,andplants;butthenumberofgenefamilymembershasexpandedinhumans,especiallyinproteinsinvolvedindevelopmentandimmunity.

•AlthoughhumansappeartohavestoppedaccumulatingrepeatedDNAover50millionyearsago,thereseemstobenosuchdeclineinrodents.Thismayaccountforsomeofthefundamentaldifferencesbetweenhominidsandrodents,althoughgeneestimatesaresimilarinthesespecies.Scientistshaveproposedmanytheoriestoexplainevolutionarycontrastsbetweenhumansandotherorganisms,includingthoseoflifespan,littersizes,inbreeding,andgeneticdrift.

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?

VariationsandMutations•Scientistshaveidentifiedabout3millionlocationswheresingle-baseDNAdifferences(SNPs)occurinhumans.Thisinformationpromisestorevolutionizetheprocessesoffindingchromosomallocationsfordisease-associatedsequencesandtracinghumanhistory.

•Theratioofgermline(spermoreggcell)mutationsis2:1inmalesvsfemales.Researcherspointtoseveralreasonsforthehighermutationrateinthemalegermline,includingthegreaternumberofcelldivisionsrequiredforspermformationthanforeggs.

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?Ledtothediscoveryofwholenewclassesofproteinsandgenes,whilerevealingthatmanyproteinshavebeenmuchmorehighlyconservedinevolutionthanhadbeensuspected.Providednewtoolsfordeterminingthefunctionsofproteinsandofindividualdomainswithinproteins,revealingahostofunexpectedrelationshipsbetweenthem.MolecularBiologyOfTheCell.Albertsetal.491-495广州市番禺区番禺大道一期工程施工T。。。Whatdoesthedrafthumangenomesequencetellus?Bymakinglargeamountsofproteinavailable,ithasyieldedanefficientwaytomassproduceproteinhormonesandvaccinesDissectionofregulatorygeneshasprovidedanimportanttoolforunravelingthecomplexregulatorynetworksbywhicheukaryoticgeneexpressioniscontrolled.MolecularBiologyOfTheCell.Albertsetal.491-495广州市番禺区番禺大道一期工程施工T。。。Howdoesthehumangenomestackup?广州市番禺区番禺大道一期工程施工T。。。•Genenumber,exactlocations,andfunctions•Generegulation•DNAsequenceorganization•Chromosomalstructureandorganization•NoncodingDNAtypes,amount,distribution,informationcontent,andfunctions•Coordinationofgeneexpression,proteinsynthesis,andpost-translationalevents•Interactionofproteinsincomplexmolecularmachines•Predictedvsexperimentallydeterminedgenefunction•Evolutionaryconservationamongorganisms•Proteinconservation(structureandfunction)•Proteomes(totalproteincontentandfunction)inorganisms•CorrelationofSNPs(single-baseDNAvariationsamongindividuals)withhealthanddisease•Disease-susceptibilitypredictionbasedongenesequencevariation•Genesinvolvedincomplextraitsandmultigenediseases•Complexsystemsbiologyincludingmicrobialconsortiausefulforenvironmentalrestoration•Developmentalgenetics,genomics

FutureChallenges:WhatWeStillDon’tKnowU.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。AnticipatedBenefitsofGenomeResearchMolecularMedicine

•improvediagnosisofdisease

•detectgeneticpredispositionstodisease

•createdrugsbasedonmolecularinformation

•usegenetherapyandcontrolsystemsasdrugs

•design“customdrugs”(pharmacogenomics)basedonindividualgeneticprofiles

MicrobialGenomics•rapidlydetectandtreatpathogens(disease-causingmicrobes)inclinicalpractice

•developnewenergysources(biofuels)

•monitorenvironmentstodetectpollutants

•protectcitizenryfrombiologicalandchemicalwarfare

•cleanuptoxicwastesafelyandefficientlyU.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。RiskAssessment•evaluatethehealthrisksfacedbyindividualswhomaybeexposedtoradiation(includinglowlevelsinindustrialareas)andtocancer-causingchemicalsandtoxinsBioarchaeology,Anthropology,Evolution,andHumanMigration•studyevolutionthroughgermlinemutationsinlineages

•studymigrationofdifferentpopulationgroupsbasedonmaternalinheritance

•studymutationsontheYchromosometotracelineageandmigrationofmales

•comparebreakpointsintheevolutionofmutationswithagesofpopulationsandhistoricalevents

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003AnticipatedBenefitsofGenomeResearch-cont.广州市番禺区番禺大道一期工程施工T。。。DNAIdentification(Forensics)•identifypotentialsuspectswhoseDNAmaymatchevidenceleftatcrimescenes

•exoneratepersonswronglyaccusedofcrimes

•identifycrimeandcatastrophevictims

•establishpaternityandotherfamilyrelationships

•identifyendangeredandprotectedspeciesasanaidtowildlifeofficials(couldbeusedforprosecutingpoachers)

•detectbacteriaandotherorganismsthatmaypolluteair,water,soil,andfood

•matchorgandonorswithrecipientsintransplantprograms

•determinepedigreeforseedorlivestockbreeds

•authenticateconsumablessuchascaviarandwine

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003AnticipatedBenefitsofGenomeResearch-cont.广州市番禺区番禺大道一期工程施工T。。。Agriculture,LivestockBreeding,andBioprocessing

•growdisease-,insect-,anddrought-resistantcrops

•breedhealthier,moreproductive,disease-resistantfarmanimals

•growmorenutritiousproduce

•developbiopesticides

•incorporateediblevaccinesincorporatedintofoodproducts

•developnewenvironmentalcleanupusesforplantsliketobacco

U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003AnticipatedBenefitsofGenomeResearch-cont.广州市番禺区番禺大道一期工程施工T。。。AnticipatedBenefits:•improveddiagnosisofdiseaseearlierdetectionofgeneticpredispositionstodiseaserationaldrugdesigngenetherapyandcontrolsystemsfordrugspersonalized,customdrugs

MedicineandtheNewGeneticsU.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003GeneTestingPharmacogenomicsGeneTherapy广州市番禺区番禺大道一期工程施工T。。。ELSI:Ethical,Legal,

andSocialIssues•Privacyandconfidentialityofgeneticinformation.•Fairnessintheuseofgeneticinformationbyinsurers,employers,courts,schools,adoptionagencies,andthemilitary,amongothers.•Psychologicalimpact,stigmatization,anddiscriminationduetoanindividual’sgeneticdifferences.•Reproductiveissuesincludingadequateandinformedconsentanduseofgeneticinformationinreproductivedecisionmaking.

•Clinicalissuesincludingtheeducationofdoctorsandotherhealth-serviceproviders,peopleidentifiedwithgeneticconditions,andthegeneralpublicaboutcapabilities,limitations,andsocialrisks;andimplementationofstandardsandquality‑controlmeasures.U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。ELSIIssues(cont.)•Uncertaintiesassociatedwithgenetestsforsusceptibilitiesandcomplexconditions(e.g.,heartdisease,diabetes,andAlzheimer’sdisease).•Fairnessinaccesstoadvancedgenomictechnologies.•Conceptualandphilosophicalimplicationsregardinghumanresponsibility,freewillvsgeneticdeterminism,andconceptsofhealthanddisease.•Healthandenvironmentalissuesconcerninggeneticallymodified(GM)foodsandmicrobes.•Commercializationofproductsincludingpropertyrights(patents,copyrights,andtradesecrets)andaccessibilityofdataandmaterials.U.S.DepartmentofEnergyGenomePrograms,GenomicsandItsImpactonScienceandSociety,2003广州市番禺区番禺大道一期工程施工T。。。BeyondtheHGP:What’sNext?HapMapSystemsBiologyExploringMicrobialGenomesforEnergyandtheEnvironmentChartgeneticvariation

withinthehumangenome广州市番禺区番禺大道一期工程施工T。。。GenomestoLife:

ADOESystemsBiologyProgramExploringMicrobialGenomesforEnergyandtheEnvironmentGoals•identifytheproteinmachinesthatcarryoutcriticallifefunctions

•characterizethegeneregulatorynetworksthatcontrolthesemachines

•characterizethefunctionalrepertoireofcomplexmicrobialcommunitiesintheirnaturalenvironments

•developthecomputationalcapabilitiestointegrateandunderstandthesedataandbegintomodelcomplexbiologicalsystems广州市番禺区番禺大道一期工程施工T。。。HapMapAnNIHprogramtochartgeneticvariation

withinthehumangenome•Begunin2002,theprojectisa3-yearefforttoconstructamapofthepatternsofSNPs(singlenucleotidepolymorphisms)thatoccuracrosspopulationsinAfrica,Asia,andtheUnitedStates.

•Consortiumofresearchersfromsixcountries•ResearchershopethatdramaticallydecreasingthenumberofindividualSNPstobescannedwillprovideashortcutforidentifyingtheDNAregionsassociatedwithcommoncomplexdiseases•Mapmayalsobeusefulinunderstandinghowgeneticvariationcontributestoresponsesinenvironmentalfactors广州市番禺区番禺大道一期工程施工T。。。DideoxySequencingDideoxysequencing(alsocalledchain-terminationorSangermethod)usesanenzymaticproceduretosynthesizeDNAchainsofvaryinglengths,stoppingDNAreplicationatoneofthefourbasesandthendeterminingtheresultingfragmentlengths.Eachsequencingreactiontube(T,C,G,andA)inthediagramcontainsaDNAtemplate,aprimersequence,andaDNApolymerasetoinitiatesynthesisofanewstrandofDNAatthepointwheretheprimerishybridizedtothetemplate;thefourdeoxynucleotidetriphosphates(dATP,dTTP,dCTP,anddGTP)toextendtheDNAstrand;onelabeleddeoxynucleotidetriphosphate(usingaradioactiveelementordye);andonedideoxynucleotidetriphosphate,whichterminatesthegrowingchainwhereveritisincorporated.TubeAhasdidATP,tubeChasdidCTP,etc./sci/techresources/Human_Genome/publicat/primer/fig12.html广州市番禺区番禺大道一期工程施工T。。。DideoxySequencingForexample,intheAreactiontubetheratioofthedATPtodidATPisadjustedsothateachtubewillhaveacollectionofDNAfragmentswithadidATPincorporatedforeachadeninepositiononthetemplateDNAfragments.Thefragmentsofvaryinglengtharethenseparatedbyelectrophoresisandthepositionsofthenucleotidesanalyzedtodeterminesequence.Thefragmentsareseparatedonthebasisofsize,withtheshorterfragmentsmovingfasterandappearingatthebottomofthegel.Sequenceisreadfrombottomtotop/sci/techresources/Human_Genome/publicat/primer/fig12.html广州市番禺区番禺大道一期工程施工T。。。DideoxySequencingPolyacrylamidegelwithsmallporesisusedtofractionatesingle-strandedDNA.Inthesizerange10to500nucleotides,DNAmoleculesthatdifferinsizebyonlyasinglenucleotidecanbeseparatedLane1-partialreplicasterminatinginGLane2-partialreplicasterminatinginALane3-partialreplicasterminatinginTLane4-partialreplicasterminatinginCAlbertsetal.MolecularBiologyoftheCell.广州市番禺区番禺大道一期工程施工T。。。Brown.Genomes2广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresisTechniquecombinestheuseofgel-filledcapillarytubeswithauniquelaserscanningsystemtosequenceeachofthefourdifferenttypesofbases--adenine,cytosine,guanine,andthymine--inasampleofDNA.CapillaryarrayelectrophoresiscutsthetimeoftheSangerdideoxymethoddownbyreplacingtheslabwithhundredsoftinygel-filledcapillaries,about100microns(fourthousandthsofaninch)ininternaldiameter,thatcanbebundledintoasinglearrayforautomateddetection./Science-Articles/Archive/automated-DNA-sequencing.html广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresisThedideoxymethodwasimprovedbytheuseoffluorescentlabels.Theprimerissynthesizedandsplitintofourbatches,eachofwhichislabeledwithadifferentfluorescentdye.Eachdyelabeledprimerisusedinasequencingreactionwithoneofthedideoxynucleotides.Thereactionproductsarepooledandanalysedinasinglelaneofasequencinggel.Afour-colourfluorescencedetectormonitorstheDNAasitmigratestothebottomofthegel.Thefluorescencesignatureisusedtoidentifytheterminalnucleotide./Science-Articles/Archive/automated-DNA-sequencing.html广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresisAmethodwasthendevelopedbasedonthiswherefluorescentdideoxynucleotideswereusedinasinglesequencingreaction.Thefragmentsarethenseparatedinasinglelaneofasequencinggelandidentifiedbythefluorescentsignature.Thelimitationsofgelelectrophoresissoonbecameapparent.Gelstakealongtimetorunandhavealimitedreproducibility.Anautomatedmethodwasmuchmoredesirable,buttheautomationofgelsrequirescomplexrobotichandling.Theuseofcapillariesallowsmuchhigherelectricalfieldstobeusedmakingtheseparationsfaster.Flexiblecapillariesarealsoeasilyincorporatedintoanautomatedinstrumentmakingsequencingcheap,fastandefficient.Howeverasinglecapillaryisstillabottleneckinthesequencingprocess.Ageliseasilycapableofrunningupto96samplessimultaneously.Toovercomethisainstrumentfittedwithanarrayofcapillarieswasdeveloped.Inthefirstinstrumentsthedetectormovedacrossthearray,butthetimelagmeanssomeinformationcanbemissed.Nowallthecapillariesaresimultaneouslymonitoredusinganarrayofphotodiodes./exemplarchem/entries/2003/leeds_chromatography/chromatography/cge.htm广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresishttp://elchem.kaist.ac.kr/BK21_SMS.web/2001_instanal/FIG/20011029/0003_ANG_2000_04463_DNA_CAE.pdf广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresisCapillaryholdsasievingmedium,whichallowsseparationofDNAfragmentsbasedontheirsizeSampleisinjectedintothecapillarybyplacingtheendofthecapillaryinthesamplesolution,andapplyingelectriccurrent.Afterinjectioniscomplete,thesampleisreplacedbyrunningbufferandelectricfieldisreappliedtodrivethesamplesthroughthecapillary.Laser-inducedfluorescencedetectorneartheendofthecapillaryrecordsthefluorescentsignalinfourdifferentchannelstoresolvethefluorescentsignalfromthefourdyes.http://elchem.kaist.ac.kr/BK21_SMS.web/2001_instanal/FIG/20011029/0003_ANG_2000_04463_DNA_CAE.pdf广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresisSmallinnerdiameterofcapillarytubereducesJouleheatingtonegligiblelevels,allowingtheuseofextremelyhighvoltage,forrapidsequencingProvidesa2-foldimprovementoverslabgelsequencingmethodshttp://elchem.kaist.ac.kr/BK21_SMS.web/2001_instanal/FIG/20011029/0003_ANG_2000_04463_DNA_CAE.pdf广州市番禺区番禺大道一期工程施工T。。。CapillaryElectrophoresis/ce/ce.html广州市番禺区番禺大道一期工程施工T。。。AutomatedSequencing/sci/techresources/Human_Genome/publicat/hgn/v10n3/images/megabaces.jpg广州市番禺区番禺大道一期工程施工T。。。/sci/techresources/Human_Genome/education/images.shtml广州市番禺区番禺大道一期工程施工T。。。Brown.Genomes2广州市番禺区番禺大道一期工程施工T。。。ShotgunSequencingBacteriophagefX174,wasthefirstgenometobesequenced,aviralgenomewithonly5,368basepairs(bp).FredericSanger,inanotherrevolutionarydiscovery,inventedthemethodof"shotgun"sequencing,astrategybasedontheisolationofrandompiecesofDNAfromthehostgenometobeusedasprimersforthePCRamplificationoftheentiregenome.TheamplifiedportionsofDNAarethenassembledbytheiroverlappingregionstoformcontiguoustranscripts(otherwiseknownascontigs).Thefinalstepinvolvedtheutilizationofcustomprimerstoelucidatethegapsbetweenthecontigsthusgivingthecompletelysequencedgenome.Sangerfirstused"shotgun"sequencingfiveyearslatertocompletethebacteriophagelsequencethatwassignificantlylarger,48,502bp.Thismethodallowedsequencingprojectstoproceedatamuchfasterratethusexpandingthescopeofrealisticsequencingventure.Sangerfirstused"shotgun"sequencingfiveyearslatertocompletethebacteriophagelsequencethatwassignificantlylarger,48,502bp./course/projects/final-4/广州市番禺区番禺大道一期工程施工T。。。ShotgunSequencingAteamheadedbyJ.CraigVenterfromtheInstituteforGenomicResearch(TIGR)andNobellaureateHamiltonSmithofJohnsHopkinsUniversity,sequencedthe1.8MbbacteriumwithnewcomputationalmethodsdevelopedatTIGR'sfacilityinGaithersburg,Maryland.Previoussequencingprojectshadbeenlimitedbythelackofadequatecomputationalapproachestoassemblethelargeamountofrandomsequencesproducedby"shotgun"sequencing.Inconventionalsequencing,thegenomeisbrokendownlaboriouslyintoordered,overlappingsegments,eachcontainingupto40KbofDNA.Thesesegmentsare"shotgunned"intosmallerpiecesandthensequencedtoreconstructthegenome.Venter'steamutilizedamorecomprehensiveapproachby"shotgunning"theentire1.8MbH.Influenzaegenome./course/projects/final-4/广州市番禺区番禺大道一期工程施工T。。。ShotgunSequencingPreviously,suchanapproachwouldhavefailedbecausethesoftwaredidnotexisttoassemblesuchamassiveamountofinformationaccurately.Software,developedbyTIGR,calledtheTIGRAssemblerwasuptothetask,reassemblingtheapproximately24,000DNAfragmentsintothewholegenome.AftertheH.Influenzaegenomewas"shotgunned"andtheclonespurifiedsufficientlytheTIGRAssemblersoftwarerequiredapproximately30hoursofcentralprocessingunittimeonaSPARCenter2000containinghalfagigabyteofRAM./course/projects/final-4/广州市番禺区番禺大道一期工程施工T。。。ShotgunSequencingVenter'sH.InfluenzaeprojecthadfailedtowinfundingfromtheNationalInstituteofHealthindicatingtheseriousdoubtssurroundinghisambitiousproposal.Itsimplywasnotbelievedthatsuchanapproachcouldsequencethelarge1.8Mbsequenceofthebacteriumaccurately.Venterprovedeveryonewrongandsucceededinsequencingthegenomein13monthsatacostof50centsperbasewhichwashalfthecostanddrasticallyfasterthanconventionalsequencing./course/projects/final-4/广州市番禺区番禺大道一期工程施工T。。。Dr.J.CraigVenterEarnedhisPh.D.inPhysiologyandPharmacologyfromtheUniversityofCaliforniaatSanDiegoandbecamearesearcherattheNationalInstitutesofHealth.WhileservingfirstasaSectionChiefandthenasaLabChiefintheNationalInstituteofNeurologicalDisordersandStroke,hedevelopedexpressedsequencetagsorEST’s,arevolutionarynewstrategyforgenediscovery.In1992,heandhiswife,Dr.ClaireFraser,foundedTheInstituteforGenomicResearchknownasTIGR,whereheservedasPresidentandChiefScientificOfficeruntil1998.Dr.VenterandhisteamatTIGRdecodedthegenomeofthebacteriumHaemophilusinfluenzae,makingitthefirstfree-livingorganismtohaveitsfullDNAdecipheredandtodatehavesequencedover30genomes.HenowservesasChairmanoftheBoardofTrusteesofTIGR.In1998,hefoundedCeleraGenomicsandannouncedthatCelerawoulddecodethehumangenomefasterandmoreeconomicallythanthepubliclyfundedconsortiumofscientists.Thatchallengeisnowcreditedwithcreatingtheclimateofurgencythatspurredcompetitionandsubstantiallyacceleratedtheproject’ssuccessfulconclusion.AttheWhiteHousepressconferenceannouncingthesequencingofthehumangenome,PresidentBillClintoncalledit“themostimportant,mostwondrousmapeverproducedbymankind.”/speakers_template.cfm?spea_id=549广州市番禺区番禺大道一期工程施工T。。。mRNASequencingAnalternativestrategyforsequencingwaspresentedduringtheearly90’sbyCraigVenter.ThefunctionalportionofthehumanDNAsupposedlyaccountsforlessthan10%(perhapslessthan5%)oftheentirehumangenome.TheHGPstrategy,i.e.sequencingeverything,couldbeconsideredaslavishnesswithresourcessincethemainpartoftheinformationlacksrelevance.ThescopeofthestrategybyVenterandco-workersistofocustheinvestigationstomessengerribonucleicacid(mRNA)insteadofDNA.ThepointofusingmRNAisthatitdoesnotincludeanynon-codingDNA.ThemRNAmoleculecanbeisolatedandusedasatemplatetosynthesizeacomplementaryDNA(cDNA)strand,whichcanthenbeusedtolocatethecorrespondinggenesonachromosomemap.ByusingVenter´smethodanincompletecopyofthegene,calledexpressedsequencetag(EST),isacquired.ESTsareusefulforlocalizingandorientingthemappingandsequencedatareportedfrommanydifferentlaboratoriesandserveaslandmarksonthedevelopingphysicalmapofthehumangenome.http://wcn.ntech.se/history.html广州市番禺区番禺大道一期工程施工T。。。WholeGenomeShotgunSequencingVenterandco-workerssuccessin1995ofsequencingtheH.influenzaebacteriumintroducedamethodcalled"wholegenomeshotgunsequencing".Theshotgunmethodinvolvesrandomlysequencingtinyclonedsectionsofthegenome,withnoforeknowledgeofwhereonachromosomethesectionoriginallycamefrom.Thepartialsequencesobtainedarethenreassembledtoacompletesequencebyuseofcomputers.Theadvantagewiththismethodisthatiteliminatestheneedfortime-consumingmapping.Bycompeting(andcooperating)thegovernmentallyfinancedhumangenomeproject(HGP)andtheprivatebiotechnologycompanyCelerahascompletedareferenceDNAsequenceofthehumangenome.BothpartiesmadetheirinformationsimultaneouslyavailableinFebruary2001,bypublishingitinontheInternetandinthescientificjournalsNatureandScience.http://wcn.ntech.se/history.html广州市番禺区番禺大道一期工程施工T。。。WholeGenomeShotgunSequencing

Afterthesequenceisshotgunnedthe10millionfragmentsofthegenomicjigsawpuzzleneedtoberecompiledintothereadablebasepairsintheproperorder.Thisme