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:作为一个模式植物,烟草在植物分子生物学研究中发挥着重要的作用。总RNA的提取质量,对于基因表达、基因克隆、cDNA文库建立、RNA原位杂交以及转基因材料鉴定等分子生物学基础研究至关重要。尤其在进行基因克隆及cDNA文库时,只有高质量的RNA,才能保证cDNA第一链合成的完整性。由于烟草中糖类、蛋白质及次生代谢物的含量较高,因此,在应用TRIzolRNA提取试剂盒进行烟草总RNA提取时,所提取的RNA产物中的蛋白质及多糖等杂质含量偏高。因此,针对这一问题,我们对TRIzol法进行了改进,并获得了高质量的烟草总RNA。经琼脂糖电泳检测,利用该方法提取的烟草总RNA,条带清晰、无拖尾现象,28S与18S的比例约为2:1。紫外吸收值的测定表明,所提取的烟草总RNA的A260/A280的值基本达到了1.9以上,说明所提取的RNA的质量较高,可广泛应用于基因的克隆及基因的表达研究。
简介:Anincreasingnumberofstructuralhomologysearchtools,mostlybasedonprofilestochasticcontext-freegrammars(SCFGs)havebeenrecentlydevelopedforthenon-codingRNAgeneidentification.SCFGscanincludestatisticalbiasesthatoftenoccurinRNAsequences,necessarytoprofilespecificRNAstructuresforstructuralhomologysearch.Inthispaper,asuccinctstochasticgrammarmodelisintroducedforRNAthathascompetitivesearcheffectiveness.Moreimportantly,theprofilingmodelcanbeeasilyextendedtoincludepseudoknots,structuresthatarebeyondthecapabilityofprofileSCFGs.Inaddition,themodelallowsheuristicstobeexploited,resultinginasignificantspeed-upfortheCYKalgorithm-basedsearch.
简介:Objective:TostudytheeffectofantisenseVEGFRNAonratC6gliomasinvivoandfindoutthefeasibilityofantiangiogenesistherapywithantisenseVEGFRNAformalignantgliomas.Methods:ParentalratC6gliomacellsandC6cellstransfectedwithantisenseVEGFcDNAwereimplantedintracerebrallyandsubcutaneouslyintoSDratsascontrolandtransfectedgroup.RatsbearingcerebralandsubcutaneousC6gliomasweretreatedwithantisenseVEGFcDNAastreatedgroupandsenseVEGFcDNAandemptyvectorascontroloftreatedgroup.Thegeneralmanifestation,survivaltime,MRIandhistopathologicalchangesofallratswereobserved.Thevolumeofsubcutaneouslyimplantedtumorswasdeterminedregularly.InsituhybridizationandimmunohistochemicalstainingwereusedfordetectionofVEGFgeneexpressionofgliomaswhilePCNAimmunostainingandTUNELmethodforexaminationofproliferationactivityandapoptosisofgliomas,respectively.Results:Thesurvivaloftheratsintransfectedandtreatedgroupwasprolonged.Thereweretworatssurvivingover90dinthetreatedgroupandtheirtumorsdisappeared.TheVEGFgeneexpression,thenumberofmicrovesselsandtheproliferationactivityweredecreasedandalargeamountofapoptoticcellscouldbefoundincerebralandsubcutaneousgliomasintreatedandtransfectedgroups.Conclusion:VEGFisoneofthecandidategenesforgenetherapyofmalignantgliomas.AntisenseVEGFRNAcombinedwithothertherapiesshouldbestudiedfurtherforenhancingthetherapeuticeffectofmalignantgliomas.
简介:目的构建表达Nogo受体(NgR)特异性siRNA199的重组质粒。方法按照E1bashir等设计原则和siRNA表达载体的要求,在合成、筛选出基因沉默效率较高的siRNA199基础上,设计带有BamHⅠ、HindⅢ酶切黏性末端、终止识别序列和LOOP环的shRNA,并将其克隆入载体pRNAT-1/6.1/Neo,构建成NgR特异siRNA199重组质粒,然后进行酶切鉴定及基因测序。结果设计的shRNA成功克隆入载体pRNAT-1/6.1/Neo,构建成NgR特异siRNA199重组质粒,酶切鉴定及基因测序表明设计序列完全相符,目的基因序列准确无误。结论重组质粒构建成功,为构建病毒载体及观察重组质粒抑制大鼠NgR基因的表达对脊髓损伤的修复作用奠定了基础。
简介:Inordertostudythefunctionalstructureofthetranscriptionterminatorsandthemechanismoftemination,asurveyofthechromatinstructure,includingthelocationofDNaseIhypersensitivesitesandthenucleosomearrangement,ofyeastADH1andFLPterminatorswasmade.TheresultsshowthatthereisnorelationshipbetweenthefunctionoftheterminatorsandtheexistenceofDNaseIhypersensitivesites.However,itisfoundthatthereisalwaysanucleosmoeattheimmediateupstreamofthetranscriptionalterminationsites.Asacontrol,thechromatinstructuresofthepBR322DNAfragmentsontheyeastshuttervectorsarealsoinvestigatedatthesametime.TherandomnucleosomearrangementonthebacterialDNAinyesastagreeswiththepublishedreports.Anewhypothesis,aboutthemechanismoftranscriptionalterminationisputforwardandthereasonofdifferentnucleosomearrengementontheDNAswhichareoriginallyfromdifferentspeciesinyeastisdiscussed.
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:目的探讨HCVRNA定量与丙型肝炎临床及病理的关系及判断疗效。方法采用美国PE公司生产的5700型荧光定量PCR仪,对665例丙型肝炎病毒单纯感染的慢性肝炎及肝硬化患者行HCVRNA定量检测,对部分患者行血生化及肝穿刺病理检查,用不同类型干扰素治疗。结果慢性丙型肝炎的HCVRNA定量值比肝炎肝硬化高(P〈0.001)。20例患者的HCVRNA定量与肝脏病理分析,HCVRNA定量与肝组织炎症及纤维化无明显关系。但肝组织炎症程度与血清生化指标有一定相关性,血清丙氨酸转氨酶的高低与肝组织的炎症程度成正相关。32例用不同干扰素治疗,疗效与HCVRNA值可能有关,HCVRNA值越低,效果越好。结论HCVRNA定量慢性丙型肝炎比肝炎肝硬化高,HCVRNA定量与肝组织炎症及纤维化无明显关系,干扰素治疗疗效与HCVRNA值可能有关。HCVRNA定量是丙型肝炎诊断和观察抗病毒治疗的一项可靠指标。
简介:以卷丹、麝香百合品种富田和离体鲜切花的花蕾为材料,比较Trizol法、异硫氰酸胍法、CTAB改进法和SDS改进法提取总RNA的效果,结果表明,SDS改进法能有效去除多糖,提取的RNA中28SrRNA亮度约为18SrRNA的两倍,OD260/OD280值介于1.7-2.2之间,卷丹RNA得率为132.52μg/g,富田RNA得率为186.88μg/g。进一步用SDS改进法分别提取富田外轮花瓣、内轮花瓣、雄蕊、雌蕊、叶和茎的RNA,同样可以获得完整的纯度高的RNA,其中28SrRNA亮度约为18SrRNA的两倍,OD260/0D280值介于1.7~2.2之间,说明此方法适用于百合各个组织RNA的提取。经RT—PCR获得了花发育基因的特异性条带,说明用SDS改进法从百合中提取的RNA质量好、产率高、完整性强,完全适合于百合进一步的分子生物学研究。
简介:Inordertostudythefunctionalstructureofthetranscriptionterminatorsandthemechanismoftermination,asurveyofthechromatinstructure,includingthelocationofDNaseIhypersensitivesitesandthenucleosomearrangement,ofyeastADH1andFLPterminatorswasmade.TheresultsshowthatthereisnorelationshipbetweenthefunctionoftheterminatorsandtheexistenceofDNaseIhypersensitivesites.However,itisfoundthatthereisalwaysanucleosomeattheimmediateupstreamofthetranscrip-tionalterminationsites.Asacontrol,thechromatinstructuresofthepBR322DNAfragmentsontheyeastshuttervectorsarealsoinvestigatedatthesametime.TherandomnucleosomearrangementonthebacterialDNAinyeastagreeswiththepublishedreports.Anewhypothesis,aboutthemechanismoftranscriptionalterminationisputforwardandthereasonofdifferentnucleosomearrangementontheDNAswhichareori-ginallyfromdifferentspeciesinyeastisdiscussed.