简介:目的:对目前最常用的检测微小RNA(miRNA)的茎环实时定量PCR法和PAP实时定量PCR法进行比较。方法:分别用茎环实时定量PCR法和PAP实时定量PCR法检测人乳腺癌细胞MCF-7中U6和23种miRNA的表达,利用定量PCR分析软件和琼脂糖凝胶电泳方法,将2种方法在引物设计难度、特异性与灵敏度,以及检测通量方面进行比较。结果:茎环法的特异性和灵敏度比PAP法高,但引物设计难度大,检测通量低;PAP法引物设计难度较低,检测通量较高,但特异性和灵敏度较差。结论:茎环法实时定量PCR适于有针对性地检测小规模miRNA,而PAP法则适于大规模miRNA筛选实验。
简介:Heterogeneousnuclearribonucleoproteins(hnRNPs)arespliceosomalmacromolecularassemblagesandthusactivelyparticipateinpre-mRNAmetabolism.Theyarecomposedofevolutionarilyconservedandtandemlyrepeatedmotifs,wherebothRNA-bindingandprotein-proteinrecognitionoccurtoachievecellularactivities.Byyetunknownmechanisms,theseribonucleoprotein(RNP)particlesaretargetedbyautoantibodiesandhenceplaysignificantroleinavarietyofhumansystemicautoimmunediseases.Thisfeaturemakesthemimportantprognosticmarkersintermsofmolecularepidemiologyandpathogenesisofautoimmunity.SinceRNPdomainisoneofthemostconservedandwidespreadscaffolds,evolutionalysesoftheseRNA-bindingdomainscanprovidefurthercluesondisease-specificepitopeformation.ThestudypresentedhereinrepresentsasequencecomparisonofRNA-recognitionregionsofrecentlyclonedandcharacterizedhumanhnRNPA3withthoseofotherrelevanthnRNPA/B-typeproteins.Theirimplicationsinhumanautoimmunityareparticularlyemphasized.
简介:在不到10年里自从它的开始,RNA干扰(RNAi)在生物医学的科学上有非凡的影响。RNAi被表明了到影响众多生物并且疾病小径。RNAi技术的开发和采纳是丰富的从基本loss-of-function工具,到药品的目标确认的染色体宽的屏蔽图书馆和治疗学的开发。然而,RNAiis的分子的机制理解远非完全。这简短评论的目的是在阐明加亮关键成就导致RNA的silencing建筑群并且到的生化学机制为这块地构画出主要挑战。
简介:Inordertostudythefunctionalstructureofthetranscriptionterminatorsandthemechanismoftemination,asurveyofthechromatinstructure,includingthelocationofDNaseIhypersensitivesitesandthenucleosomearrangement,ofyeastADH1andFLPterminatorswasmade.TheresultsshowthatthereisnorelationshipbetweenthefunctionoftheterminatorsandtheexistenceofDNaseIhypersensitivesites.However,itisfoundthatthereisalwaysanucleosmoeattheimmediateupstreamofthetranscriptionalterminationsites.Asacontrol,thechromatinstructuresofthepBR322DNAfragmentsontheyeastshuttervectorsarealsoinvestigatedatthesametime.TherandomnucleosomearrangementonthebacterialDNAinyesastagreeswiththepublishedreports.Anewhypothesis,aboutthemechanismoftranscriptionalterminationisputforwardandthereasonofdifferentnucleosomearrengementontheDNAswhichareoriginallyfromdifferentspeciesinyeastisdiscussed.
简介:目的:通过对TRIzol一步法进行改进,建立一种从富含胶原蛋白、多糖及色素的仿刺参体壁提取总RNA的有效方法。方法:样品在液氮中研磨并用TRIzol匀浆后再进行抽提;对TRIzol一步法提取的总RNA进行DNaseⅠ消化和酚氯仿抽提,用2.5mol/L的醋酸钾沉淀,并加入适量糖原(10mg/mL)与RNA共沉淀。结果:琼脂糖凝胶电泳和紫外分光光度法以及RT-PCR检测结果表明,改进的方法能够有效去除基因组DNA、蛋白、多糖及色素的污染,RNA的产率提高。结论:制备的总RNA纯度高,完整性好,能够满足mRNA差异显示RT-PCR等分子生物学研究的要求,是一种提取仿刺参体壁及其他富含黏多糖、胶原蛋白和色素的动物组织总RNA的有效方法。
简介:比期望,非编码的RNA(ncRNA)基因才是更众多的。然而,与计算算法或生物实验识别ncRNAs仍然是一项困难的任务。最近的报告建议了ncRNAs可以也出现在表示顺序标签(EST的)数据库。不过,内部遗传因子的EST几乎没收到很少注意并且糟糕由于他们的低丰富被注解。这里,我们为从人的EST发现ncRNA基因开发了计算策略。我们首先收集了位于的EST内部遗传因子的区域并且别让详细注解。内部遗传因子的区域被划分成非重叠的50-nt窗口,从UCSC数据库获得的PhastCons分数被分到这些窗口。我们使有超过0.8的PhastCons分数并且有至少三支持EST充当种子的窗户保存。相应于种子的EST的每簇被装配进长contig。我们使用了二个标准从这些contigs为ncRNA抄本屏蔽:第一是最长预言的开的读物框架是不到300nt,第二是可能的Pol-II倡导者在contigs在上游或下游的2,000nt以内存在。作为结果,118新奇ncRNA基因从人的低丰富EST被识别。七个随机选择的候选人,六在由RT-PCR出现的人的2BS房间被抄录。我们的工作证明EST为检测新奇ncRNA基因是“隐藏的财富”。
简介:Humantumornecrosisfactorα(hTNFα),apleiotropiccytokinewithactivitiesrangingfromhostdefensemechanismsininfectionandinjurytoseveretoxicityinsepticshockorotherrelateddiseases,isapromisingtargetfordrugscreening.UsingtheSELEX(systematicevolutionofligandsbyexponentialenrichment)process,weisolatedoligonucleotideligands(aptamers)withhighaffinitiesforhTNFα.Aptamerswereselectedfromastartingpoolof40randomizedsequencescomposedofabout1015RNAmolecules.RepresentativeaptamersweretruncatedtotheminimallengthwithhighaffinityforhTNFαandwerefurthermodifiedbyreplacementof2'-OHwith2'-Fand2'-NH2atallribopurinepositions.ThesemodifiedRNAaptamerswereresistanttonuclease.ThespecificityoftheseaptamersforhTNFαwasconfirmed,andtheiractivitytoinhibitthecytotoxicityofhTNFαonmouseL929cellswasdetermined.Resultsdemonstratedthatfour2'-NH2-modifiedaptamersboundtohTNFαwithhighaffinityandblockedthebindingofhTNFαtoitsreceptor,thusprotectingtheL929cellsfromthecytotoxicityofhTNFα.OligonucleotideaptamersdescribedherearepotentialtherapeuticsanddiagnosticsforhTNFc-relateddiseases.
简介:以田间幼嫩叶片为试材,建立枣RNA改良CTAB提取法,改良之处包括利用巯基乙醇和PVP联合去除多酚、CTAB与异硫酸氰胍联合促进RNA释放及加入糖原提高产率等。改良CTAB法提取液组成:2%CTAB,4mol/L异硫酸氰胍,100mmol/LTris-HCl(pH8.0),20mmol/LEDTA(pH8.0),2%PVP,4%β-巯基乙醇,250μg/ml糖原。进而采用Trizol试剂法、改良CTAB法、改进SDS-酚法、热硼酸法和异硫氰酸胍法5种方法分别对枣组培苗、幼叶、幼嫩枝皮、根皮和枣果5种器官和组织进行了总RNA提取。结果表明,组培苗RNA提取以Trizol试剂法为最佳,田间幼叶和成熟果实宜采用改良CTAB法,幼嫩枝皮和根皮宜采用改良CTAB法或改进SDS-酚法;本研究建立的改良CTAB法可作为枣不同器官和组织RNA提取的通用方法;根据季节可从不同器官和组织中获得高质量RNA;枣组织RNA含量相差较大,以幼嫩叶片含量最高,其次为组培苗、枝皮、枣果和根皮。
简介:RNA干扰(RNAi)是生物体内源基因发生转录后特异性降解的一种生理现象,作为抵抗病毒的免疫机制,广泛存在于生物体内。RNAi在秀丽隐杆线虫中的发生机制已明确,但昆虫的系统性RNAi不同于线虫,在昆虫中尚未发现线虫跨膜蛋白SID.2的同源蛋白,且果蝇中不存在依赖于RNA的RNA聚合酶(RdRP),但存在具有相似活性的物质。昆虫发生RNAi的效率不仅与靶标基因自身及双链RNA的选择有关,而且与虫体的发育状态及摄入双链RNA的剂量相关。随着RNAi在昆虫中作用特点的阐明,RNAi的应用价值也逐渐体现。近年来,通过RNAi沉默靶标基因,不但促进了昆虫基因功能研究的发展,而且被广泛用于重要农业害虫抗药性基因的研究。最新研究表明,RNAi结合第2代测序技术,针对非模式昆虫,能迅速找到具有致死效应的靶标序列,加快了利用RNAi技术生产生物农药的步伐。
简介:Honeybees(Apismellifera)havehaplodiploidsexdetermination:malesdevelopfromunfertilizedeggsandfemalesdevelopfromfertilizedones.Thedifferencesinlarvalfoodalsodeterminethedevelopmentoffemales.Herewecomparedthetotalsomaticgeneexpressionprofilesof2-dayand4-day-olddrone,queenandworkerlarvaebyRNASeq.Theresultsfromaco-expressionnetworkanalysisonallexpressedgenesshowedthat2-day-olddroneandworkerlarvaewerecloseringeneexpressionprofilesthan2-day-oldqueenlarvae.Thisindicatedthatforyounglarvae(2-day-old)environmentalfactorssuchaslarvaldiethaveagreatereffectongeneexpressionprofilesthanploidyorsexdetermination.Droneshadthemostdistinctgeneexpressionprofilesatthe4-daylarvalstage,suggestingthathaploidy,orsexdramaticallyaffectsthegeneexpressionofhoneybeelarvae.Dronelarvaeshowedfewerdifferencesingeneexpressionprofilesatthe2-dayand4-daytimepointsthantheworkerandqueenlarvalcomparisons(598against1190and1181),suggestingadifferentpatternofgeneexpressionregulationduringthelarvaldevelopmentofhaploidmalescomparedtodiploidfemales.Thisstudyindicatesthatearlyindevelopmentthequeencastehasthemostdistinctgeneexpressionprofile,perhapsreflectingtheveryrapidgrowthandmorphologicalspecializationofthiscastecomparedtoworkersanddrones.Laterindevelopmentthehaploidmaledroneshavethemostdistinctgeneexpressionprofile,perhapsreflectingtheinfluenceofploidyorsexdeterminationongeneexpression.
简介:AnewmethodforsimulatingthefoldingpathwayofRNAsecondarystructureusingthemodifiedantcolonyalgorithmisproposed.ForagivenRNAsequence,thesetofallpossiblestemsisobtainedandtheenergyofeachstemiscalculatedandstoredattheinitialstage.Furthermore,amorerealisticformulaisusedtocomputetheenergyofmulti-branchloopinthefollowingiteration.Thenafoldingpathwayissimulated,includingsuchprocessesasconstructionoftheheuristicinformation,theruleofinitializingthepheromone,themechanismofchoosingtheinitialandnextstemandthestrategyofupdatingthepheromonebetweentwodifferentstems.FinallybytestingRNAsequenceswithknownsecondarystructuresfromthepublicdatabases,weanalyzetheexperimentaldatatoselectappropriatevaluesforparameters.ThemeasureindexesshowthatourprocedureismoreconsistentwithphylogeneticallyprovenstructuresthansoftwareRNAstructuresometimesandmoreeffectivethanthestandardGeneticAlgorithm.