简介:近些年来,DNA条形码技术为便捷的物种鉴定提供了很大的帮助,但随着该技术的发展,也出现了一系列的问题。微型条形码技术是作为DNA条形码技术的补充而出现的一项新兴技术,具体是指通过通用引物扩增出比细胞色素c氧化酶I号基因全序列更短的一段序列,并通过该序列进行物种鉴定、分类等研究工作。作为一项新兴技术,其优点包括,适用于部分降解的DNA样品的目的基因扩增,能够很好地解决环境混合样品多样性的调查等。但是,该技术所选DNA片段非常短,因此标记序列包含的遗传信息有限,在鉴定的精确度方面和COI全条形码存在一定的差距。本文在总结前人研究的基础上,简要概述了微型条形码技术的优缺点,并对其未来在害虫分子识别方面的应用做了初步探讨。
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:ThebindingofCo(bpy)2dppz3+tocalfthymusDNAwasinvestigatedbyusingabsorptionandemissionspectroscopy,DNAmeltingtechniques,cyclicvoltammetry,viscosityandelectro-phoresismeasurements,wherebpyis2,2’-bipyridyl,dppzisdipyrido[3,2-o:2’,3’-c]phenazine.Thebindingcompoundshowsabsorptionhypochromicity,fluorescenceenhancement,andincreasingofDNAmeltingtemperatureandthespecificviscosity.CVmeasurementshowstheshiftsinoxidation-reductionpotentialandchangeinpeakcurrentwithadditionofDNA.ThecompoundisalsoshowntobemoreefficientphotosensitisersforstrandbreaksinplasmidDNA.
简介:DNAcondensationisanimportantprocessinmanyfieldsincludinglifesciences,polymerphysics,andappliedtechnology.Inthenucleus,DNAiscondensedintochromosomes.Inpolymerphysics,DNAistreatedasasemi-flexiblemoleculeandapolyelectrolyte.Manyagents,includingmulti-valentcations,surfactants,andneutralpoorsolvents,cancauseDNAcondensation,alsoreferredtoascoil–globuletransition.Moreover,DNAcondensationhasbeenusedforextractionandgenedeliveryinappliedtechnology.ManyphysicaltheorieshavebeenpresentedtoelucidatethemechanismunderlyingDNAcondensation,includingthecounterioncorrelationtheory,theelectrostaticzippertheory,andthehydrationforcetheory.Recentlyseveralsingle-moleculestudieshavefocusedonDNAcondensation,sheddingnewlightonoldconcepts.Inthisdocument,themulti-fieldconceptsandtheoriesrelatedtoDNAcondensationareintroducedandclarifiedaswellastheadvancesandconsiderationsofsingle-moleculeDNAcondensationexperimentsareintroduced.
简介:TheeffectofCdionsonsalmonspermDNAwasstudiedbymeansofcirculardichroism(CD),Ramanspectroscopy,X-rayphotoelectronspectroscopy(XPS)andfluorescencespectroscopy.TheCDspectralandfluorescentprobe-acriflavineresultsindicatethattheDNAunderwentaconformationchangeupontheadditionofCdions.XPSandRamanstudiesrevealthatthereexistedinteractionsbetweenCdionsandthephosphategroupsoftheDNA.Inaddition,anewbandappearedat803cm-1intheRamanspectra,whichcanbeattributedtocharacterizing"marker"bandofA-DNA.ItisconcludedthatCdionscanbecoordinatedbythephosphategroupsoftheDNAandinducetheconformationchangesoftheDNAfromB-DNAtoA-DNA.
简介:HydrolysisofDNAisanimportantenzymaticreaction,butitisexceedinglydifficulttomimicinthelaboratorybecauseofthestabilityofhydrolysisofDNA.Inthispaper,thecleavageactivityofcomplexesformedbetweenCu(Ⅱ)andfourdifferentaminoacidoraminoacidmethylesteronDNAisstudiedbygelelec-trophoresis.ItisfoundthatDNAcouldbecleavedbyCu(Ⅱ)-L-HisandCu(Ⅱ)-L-Hismethylestercomplexesandtheefficiencyofcleavageislargelydependentonthemetalion-to-ligandratio.FurtherexperimentsshowthatthecleavageofDNAmediatedbyCu(Ⅱ)-L-HiscomplexesoccursviaahydrolyticmechanismandtheactivechemicalspeciesthataffectsDNAcleavageisproposedtobeMI2H+andML2H22+.