大鼠松果体Clock基因和苏烷脘N-乙酰转移酶基因的昼夜节律性表达及光照影响VIP免费

生理学报ActaPhysiologicaSinica,February25,2005,57(1):97-102http://www.actaps.com.cn97研究论文Received2004-04-23Accepted2004-09-29ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina(No.30170295),MedicalDevelopmentalFoun-dationofSoochowUniversity(No.EE134031)andYoungTeacher’sResearchFoundationofSoochowUniversity(No.Q3134044).*Correspondingauthor.Tel:+86-512-65125041;Fax:+86-512-65304830;E-mail:tongjian@suda.edu.cn大鼠松果体Clock基因和芳烷脘N-乙酰基转移酶基因的昼夜节律性表达及光照影响王国卿1,2,杜玉珍2,童建2,*苏州大学1医学院基础医学系生理学教研室；2放射医学与公共卫生学院卫生毒理学教研室，苏州215007摘要：探讨12h光照、12h黑暗交替(12h-light:12h-darkcycle,LD)及持续黑暗(constantdarkness,DD)光制下松果体Clock基因和芳烷脘N-乙酰基转移酶基因(arylalkylamineN-acetyltransferasegene,NAT)是否存在昼夜节律性表达及其光反应变化。Sprague-Dawley大鼠在LD和DD光制下分别被饲养4周(n=36)和8周(n=36)后，在一昼夜内每隔4h采集一组松果体组织(n=6)，提取总RNA，用竞争性定量RT-PCR测定不同昼夜时点样品中Clock及NAT基因的mRNA相对表达量，通过余弦法和ClockLab软件获取节律参数，并经振幅检验是否存在昼夜节律。结果如下：(1)在DD或LD光制下，松果体Clock和NAT基因mRNA的表达均呈现夜高昼低的节律性振荡(P<0.05)。(2)与DD光制下比较，LD光制下松果体Clock和NAT基因的表达振幅及峰值相的mRNA水平均降低(P<0.05)。(3)在DD或LD光制下，Clock和NAT基因之间显示相似的节律性表达(P>0.05)。结果表明，Clock和NAT基因在松果体中存在同步的内源性昼夜节律表达，光照作用可使其表达下调。关键词：Clock基因;NAT基因;昼夜节律;光照;松果体中图分类号：Q811.213;R322.55;R852.6;R322.81CircadianrhythmsandlightresponsesofclockgeneandarylalkylamineN-acetyltransferasegeneexpressionsinthepinealglandofratsWANGGuo-Qing1,2,DUYu-Zhen2,TONGJian2,*1DepartmentofPhysiology,MedicalSchool;2DepartmentofToxicology,SchoolofRadiationMedicineandPublicHealth,SoochowUniversity,Suzhou215007,ChinaAbstract:ThisstudywastoinvestigatethecircadianrhythmsandlightresponsesofClockgeneandarylalkylamineN-acetyltransferase(NAT)geneexpressionsintheratpinealglandunderthe12h-light:12h–darkcyclecondition(LD)andconstantdarkness(DD).Sprague-DawleyratshousedunderthelightregimeofLD(n=36)for4weeksandofDD(n=36)for8weeksweresampledforthepinealglandonceagroup(n=6)every4hinacircadianday.ThetotalRNAwasextractedfromeachsampleandthesemiquantitativereversetranscriptionpolymerasechainreaction(RT-PCR)wasusedtodeterminethetemporalchangesinmRNAlevelsofClockandNATgenesduringdifferentcircadiantimesorzeitgebertimes.Thedatawereanalysedbythecosinefunctionsoftware,ClockLabsoftwareandtheamplitudeFtestwasusedtorevealthecircadianrhythm.Themainresultsobtainedareasfollows.(1)InDDorLDcondition,bothofClockandNATgenesmRNAlevelsinthepinealglandshowedrobustcircadianoscillation(P<0.05)withthepeakatthesubjectivenightoratnight-time.(2)IncomparisonwithDDregime,theamplitudesandthemRNAlevelsatpeaksofClockandNATgenesexpressionsinLDinthepinealglandweresignificantlyreduced(P<0.05).(3)InDDorLDcondition,thecircadianexpressionsofNATgeneweresimilarinpatterntothoseofClockgeneinthepinealgland(P>0.05).ThesefindingssuggestthattheexpressionsofClockandNATgenesinthepinealglandnotonlyshowremarkablysynchronousendogenouscircadianrhythmicchanges,butalsoresponse生理学报ActaPhysiologicaSinica,February25,2005,57(1):97-10298大多数生物体的生理功能表现出以24h为周期的昼夜节律。产生这种节律的结构基础是分子计时器——昼夜节律生物钟。哺乳类动物的生物钟已被定位于下...