简介:CleavageofchromosomalDNAintooligonucleosomalsizefragmentsisanintegralpartofapoptosis.ElegantbiochemicalworkidentifiedtheDNAfragmentationfactor(DFF)asamajorapoptoticendonucleaseforDNAfragmentationinvitroGeneticstudiesinmicesupporttheimportenceofDFFinDNAfragmentationandpossiblyinapoptosisinvivo.RecentworkalsosuggeststheexistenceofadditionalendonucleasesforDNAdegradation.Understandingtherolesofindividualendonucleasesinapoptosis,andhowtheymightcoordinatetodegradeDNAindifferenttissuesduringnormaldevelopmentandhomeostasis,aswellasinvariousdiseasedstates,willbeamajorresearchfocusinthenearfuture.
简介:<正>Apoptosisisahighlyregulatedphysiologicalprocesscriticalindevelopmentandtissuehomeostasis.Abnormalapoptosiscanleadtodiseaseconditionsincludingneurodegeneration,autoimmunityandcancer.DNAfragmentationisanintegralpartofapoptosisandhaslongbeensuspectedtobeofcriticalimportanceincleaninguppotentiallyantigenicDNAandgeneticmaterialcapableofinducingneoplasmictransformationinneighboringcells.DirectevidenceforthisfunctionofDNAfragmentationhowever,isstilllacking.TheidentificationofaheterodimericDNAfragmentationfactor45and40(DFF45andDFF40,alsocalledICADforInhibitorofCaspaseActivatedDNaseandCADforCaspaseActivatedDNaserespectively)aswellas
简介:[背景]西花蓟马于2003年入侵中国后,迅速传播扩散并在局部区域造成严重危害,对我国蔬菜、花卉及果树产业的健康发展构成了巨大威胁.[方法]以线粒体DNA标记技术,对采自我国13个省(市)不同地理区域西花蓟马种群的175条COⅠ基因进行序列变异及群体遗传结构分析.[结果]试验共检测到13个单倍型,各地理种群西花蓟马的单倍型多样性Hd较高,为0.691,而核苷酸多样性π较低,为0.00652.总体固定指数Fst为0.24359,基因流Nm为0.78;种群之间固定指数和基因交流分析表明,我国各地理种群间可能出现了一定分化.种群间AMOVA分析显示,我国西花蓟马的遗传变异主要来自种群内部.对国内外不同地理种群COⅠ基因序列的单倍型进行聚类分析表明,我国西花蓟马有2个品系,即温室品系和羽扇豆品系,其中羽扇豆品系来源于新西兰和荷兰,而广泛存在的温室品系存在多个入侵来源.[结论与意义]我国西花蓟马各地理种群的发生,既与国际贸易活动有关,又与国内蔬菜、花卉、水果等的调运以及观光旅游密不可分.研究结果对西花蓟马的有效阻截及其种群扩张趋势监测意义重大.
简介:AsthetopologicalpropertiesofeachspotinDNAmicroarrayimagesmayvaryfromoneanother,weemployedgranulometriestounderstandtheshape-sizecontentcontributedduetoasignificantintensityvaluewithinaspot.Analysiswasperformedonthemicroarrayimagethatconsistedof240spotsbyusingconceptsfrommathematicalmorphology.Inordertofindoutindicesforeachspotandtofurtherclassifythem,weadoptedmorphologicalmultiscaleopenings,whichprovidedmicroarraysatmultiplescales.Successiveopenedmicroarraysweresubtractedtoidentifytheprotrusionsthatweresmallerthanthesizeofstructuringelement.Spot-wisedetails,intermsofprobabilityoftheseobservedprotrusions,werecomputedbyplacingaregularlyspacedgridonmicroarraysuchthateachspotwascenteredineachgrid.Basedontheprobabilityofsizedistributionfunctionsoftheseprotrusionsisolatedateachlevel,weestimatedthemeansizeandtextureindexforeachspot.Withthesecharacteristics,weclassifiedthespotsinamicroarrayimageintobrightanddullcategoriesthroughpatternspectrumandshape-sizecomplexitymeasures.Thesesegregatedspotscanbecomparedwiththoseofhybridizationlevels.
简介:Apoptosiscanbetriggeredbyavarietyofstimuliincludingdeathfactors,anti-cancerdrugsandfactor-deprivation.Theseapoptoticcellsareswiftlyphagocytosedbymacrophagestopreventthereleaseofnoxiousorinflammatorymaterialsfromdyingcells.ThemolecularanalysisofFasligand(adeathfactor)-inducedapoptosisindicatedthatacascadeofproteases(caspases)isactivatedduringthisprocess,whicheventuallyactivatesaspecificDNase(caspase-activatedDNase).CADexistsasacomplexwithitsinhibitor(ICAD)inproliferatingcells.Whenthecellsaretriggeredtoapoptosis,caspases,inparticularcaspase3,inthedownstreamofthecaspasecascadecleaveICAD,whichreleasesCADtocauseDNAdegradationinnuclei.
简介:The2004SoutheastAsiaTsunamikillednearly5,400peopleinSouthernThailand,includingforeigntouristsandlocalresidents.TorecoverDNAevidenceasmuchaspossiblefromtheseriouslydecomposedbodies,weexploredproceduresofsamplepreparationfrombothboneandtoothsamplesaswellasbothmitochondrialandnuclearmarkers.DespitehavingfailedtorecoverenoughDNAfornuclearmarkertyping,wesucceededinobtainingfullyinformativeresultsformitochondrialmarkers(HV1andHV2)from258toothsampleswithasuccessrateof51%(258/507).UsinganorganicDNAextractionmethodcoupledwithanultrafiltrationstep,weobtained16STR(including13CODISloci,onesexdiscriminationlocus,andtwoIdentifilerloci)profilesfor834sampleswithasuccessrateof79%(834/1,062).Inaddition,bycomparingtheallelicfrequenciesbetweenthetypedsamplesasagroupandotherindexpopulations,weconcludethattheThaitsunamivictimsareacombinedgroupofseveralpopulations.Ourresultsprovidevaluableevidenceandprotocolsforthefutureforensicpractice.
简介:Eelfamilyisahugeone,inwhichmanykindsofeelsespeciallysomemigratoryeels,bearstrongresemblancetoeachother,andarethereforedifficulttobeidentified.Inthisstudy29randomprimerswereusedtomakeRAPDanalysisforJapaneseseel(Anguillajaponica),Europeaneel(Anguillaanguilla)andPikeeel(Muraenesoxcinereus).Andtotally299fragmentswerecounted.Sharedorspecificfragmentswerecountedandgeneticsimilarityorgeneticdistancewerecalculated.ThegeneticsimilaritybetweenJapaneseeelandPikeeelis0.68andthegeneticdistancebetweenthemis0.32;thosebetweenEuropeaneelandPikeeelare0.72and0.28respectively,andbetweenJapaneseeelandEuropeaneelare0.74and0.25respectively.Themethodhasbeenshowntobesuitabletomolecularidentificationofeels.Itprovidesanalternativeapproachtodeterminetherelationshipbetweenspecies.
简介:DNA聚合酶III是为DNA的复制负责的五eubacterialDNA聚合酶之一双。在DNA聚合酶III核心酶的十个子单元之中,高山哈子单元两个都为polymerizing催化反应DNA海滨。在这研究,我们提取了高山的genomic序列哈从159的子单元定序eubacterial染色体,并且执行了基于顺序的种系发生、结构的分析。我们发现所有eubacterial染色体有至少一座高山哈子单元,哪个形式homodimers或heterodimers。种系发生并且领域高山的结构的分析以及拷贝数字变化哈在每个细菌的子单元显示高山的分类哈子单元进四个基本的组:polC,dnaE1,dnaE2,和dnaE3。这个分类具有在染色体作文分析的本质。我们也巩固了命名惯例在基因注解避免进一步的混乱。
简介:在源于mitochondrial机能障碍的氧化phosphorylation的改变长被假设了涉及tumorigenesis。线粒体最近被显示了在调整规划房间死亡和房间增长起一个重要作用。而且,mitochondrialDNA(mtDNA)变化在各种各样的癌症房间被发现了。然而,在tumorigenesis的这些mtDNA变化的角色仍然保持大部分未知。这评论集中于基本mitochondrial遗传,mtDNA变化和与癌症联系的结果的mitochondrial机能障碍。潜在的分子的机制,调停从mtDNA变化的致病和到tumorigenesis的mitochondrial机能障碍也被讨论。
简介:Humanpolymorphonuclearleukocytes(PMN)havebeenreportedtocompletelylackofDNA-dependentproteinkinase(DNA-PK)whichiscomposedofKuproteinandthecatalyticsubunitDNA-PKcs,neededfornonhomologousend-joining(NHEJ)ofDNAdouble-strandbreaks.PromyelocyticHL-60cellsexpressavariantformofKuresultinginenhancedradiationsensitivity.ThisraisesthequestioniflowefficiencyofNHEJ,instrumentalforthecellularrepairofoxidativedamage,isanormalcharacteristicofmyeloiddifferentiation.HereweconfirmedthecompletelackofDNAPKinPMNproteinextracts,andtheexpressionofthetruncatedKu86variantforminHL-60.However,thisdegradationofDNA-PKwasshowntobeduetoaDNA-PK-degradingproteaseinPMNandHL-60.Inaddition,byusingaprotease-resistantwholecellassay,bothKu86andDNA-PKcscouldbedemonstratedinPMN,suggestingthepreviouslyreportedabsenceinPMNofDNA-PKtobeanartefact.ThelevelsofKu86andDNA-PKcsweremuchreducedinPMN,ascomparedwiththatofthelymphocytes,whereasHL-60displayedamarkedlyelevatedDNA-PKconcentration.Inconclusion,ourfindingsprovideevidenceofreduced,notdepletedexpressionofDNA-PKduringthematurestagesofmyeloiddifferentiation.
简介:TounderstandtheDNA-methylationmediatedgenesilencingmechanisms,weanalyzedincellcultureofthepromoterfunctionoftheMAGE-A1gene,whichisfrequentlydemethylatedandover-expressedinhumanhepatocellularcarcinoma.WehaveestablishedthecorrelationoftheDNAmethylationofthepromoterCpGislandwithexpressionstatusofthisgeneinapaneloftheestablishedlivercancercelllines.ThecrucialCpGdinucleotide(s)withintheminimalpromotersubjectedtothecontrolmediatedbyDNAmethylationwithprofoundbiologicalfunctionswasalsodelineated.Furthermore,anovelsequence-specificDNA-proteininteractionatthe-30CpGdinucleotideupstreamofthegenewasfoundhavingavitalparttoplayintheDNAmethylationmediatedtranscriptionsilencingoftheMAGE-A1gene.OurresultswouldnotonlyprovidenewinsightsintotheDNAmethylationmediatedmechanismsovertranscriptionoftheMAGE-A1gene,butalsopavethewayforfurtherdefiningthecross-talkamongDNAmethylation,histonemodificationandchromatinremodelingindetail.
简介:Meiotic前期我是一个长、复杂的阶段。相应再结合是在meiotic前期期间发生在相应染色体之间的一个重要过程我。chiasmata的形成,它一起保持相应染色体直到中期我到后期,我转移,为合适的染色体分离是批评的。最近的研究建议了SPO11蛋白质在产生被认为是相应再结合的起点的双strandedDNA裂缝(DSB)的地点在很多个有机体保存了功能。DSB的这些地点处理要求RecA相当或相同的事物的功能,例如RAD51,DMC1,和其它,由变异的研究建议了;因此,修理这些meioticDSB的失败导致反常chromosomal引申,导致破坏成熟分裂。这些RecA相当或相同的事物的功能上的最近的发现改进了位于meiotic下面的机制的理解相应再结合。
简介:DNAbarcodingisapowerfulapproachforcharacterizingspeciesoforganisms,especiallythosewithalmostidenticalmorphologicalfeatures,therebyhelpingtotoestablishphylogeneticrelationshipsandrevealevolutionaryhistories.Inthisstudy,wechosea648-bpsegmentofthemitochondrialgene,cytochromecoxidasesubunit1(COI),asastandardbarcoderegiontoestablishphylogeneticrelation-shipsamongbrineshrimp(Artemia)speciesfrommajorhabitatsaroundtheworldandfurtherfocusedonthebiodiversityofArtemiaspeciesinChina,especiallyintheTibetanPlateau.SamplesfromfivemajorsaltlakesoftheTibetanPlateaulocatedataltitudesover4,000mshowedcleardifferencesfromotherArtemiapop-ulationsinChina.Wealsoobservedtwoconsistentaminoacidchanges,153A/Vand183L/F,intheCOIgenebetweenthehighandlowaltitudespeciesinChina.Moreover,indelsintheCOIsequencewereidentifiedincystandadultsamplesuniquetotheCoQenpopulationfromtheTibetanPlateau,demonstratingtheneedforadditionalinvestigationsofthemitochondrialgenomeamongTibetanArtemiapopulations.
简介:RecognitionofDNAdamageisacriticalstepforDNAdamage-mediatedcellularresponse.XPCisanimportantDNAdamagerecognitionproteininvolvedinnucleotideexcisionrepair(NER).WehavestudiedtheXPCproteinincisplatinDNAdamagingtreatment-mediatedcellularresponse.ComparisonofthemicroarraydatafrombothnormalandXPCdefectivehumanfibroblastsidentified861XPC-responsivegenesinthecisplatintreatment(withminimumfoldchange≥1.5).Thecellcycleandcellproliferation-relatedgenesarethemostaffectedgenesbytheXPCdefectinthetreatment.Manyothercellularfunctiongenes,especiallytheDNArepairandsignaltransduction-relatedgenes,werealsoaffectedbytheXPCdefectinthetreatment.Tovalidatethemicroarraydata,thetranscriptionlevelsofsomemicroarray-identifiedgeneswerealsodeterminedbyanRT-PCRbasedrealtimePCRassay.TherealtimePCRresultsareconsistentwiththemicroarraydataformostofthetestedgenes,indicatingthereliabilityofthemicroarraydata.Tofurthervalidatethemicroarraydata,thecisplatintreatment-mediatedcaspase-3activationwasalsodetermined.TheWesternblothybridizationresultsindicatethattheXPCdefectgreatlyattenuatesthecisplatintreatment-mediatedCaspase-3activation.Weelucidatedtheroleofp53proteinintheXPCproteinDNAdamagerecognition-mediatedsignalingprocess.TheXPCdefectreducesthecisplatintreatment-mediatedp53response.TheseresultssuggestthattheXPCproteinplaysanimportantroleinthecisplatintreatment-mediatedcellularresponse.Itmayalsosuggestapossiblemechanismofcancercelldrugresistance.