简介：Inthispaper,wetooktheleadinstudyingonspecificityofthemicrosatelliteDNAlociandapplicabilityofmicrosatelliteDNAprimersinprotozoa.Inordertostudycharactersofmicrosatellitesinfree-livingprotozoa,eightmicrosatellitelociprimersdevelopedfromTrypanosomacruzi(MCLE01,SCLE10,MCLE08,SCLE11,MCLF10,MCLG10,MCL03,MCL05)wereemployedtoamplifymicrosatelliteinfourfree-livingprotozoa,includingBododesignis,EuglenagracilisFACHB848,ParameciumbruziseandTetrahymenathermophilaBF1.IntheamplificationsystemsofP.bruzise,fourloci(SCLE10,SCLE11,MCLF10,MCL03)wereamplifiedsuccessfully,andfouramplificationfragmentswereinpropersize.IngenomeofE.gracilisFACHB848,fiveofeightprimersbroughtfiveclearamplificationbands.InB.designis,three(No.4,5and7)ofeightlociproducedclearandsharpproductswithoutstutterbands,whereasnobandsappearedinT.thermophilaBF1.Further,eight300-500bpamplificationfragmentswereclonedandsequenced.Nevertheless,allsequencedproductsdidnotcontaincorrespondingmicrosatellitesequence,althoughBodoisinthesameorderandhasthenearestphylogeneticrelationwithTrypanosomaamongthesefourspecies.Thus,themicrosatelliteDNAprimerscannotbeappliedamongorderormorefartaxa,andthespecificityofmicrosatelliteDNAisveryhighinprotozoa.TheresultsofthisstudywillcontributetoourunderstandingofmicrosatelliteDNAinprotozoa.