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《insertion sequence-related genetic variation in resting escherichia coli k-12》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、Copyright01994bytheGeneticsSocietyofAmericaInsertionSequence-RelatedGeneticVariationinRestingEscherichiacoliK-12ThierryNaas,*MichelBlot,*WalterM.FitchtandWernerArber**AbteilungMikrobiologie,BiozentrumderUniversitatBasel,CH-4056Basel,Switzerland,andtDepartmentofEcologyandEvolutionaryBiology,
2、UniversityofCalifornia,Zruine,California92717ManuscriptreceivedSeptember13,1993AcceptedforpublicationNovember10,1993ABSTRACTBacterialsubclonesrecoveredfromanoldstabcultureofEscherichiacoliK-12revealedahighdegreeofgeneticdiversity,whichoccurredinspiteofaveryreducedrateofpropagationduringstor
3、age.Thisconclusionisbasedonapronouncedrestrictionfragmentlengthpolymorphism(RFLP)detecteduponhybridizationwithinternalfragmentsofeightresidentinsertionsequences(IS).GeneticdiversitywasdependentontheISconsideredand,inmanycases,aclearconsequenceofIStransposition.IS5wasparticularlyactiveintheg
4、enerationofvariation.AllsubclonesinwhichIS30hadbeenactivetestifytoaburstofIS30transposition.Thiswascorrelatedwithalossofprototrophyandareducedgrowthonrichmedia.ApedigreeoftheentireclonecouldbedrawnfromtheRFLPpatternsofthesubclones.Outof118subclonesanalyzed,68differentpatternswerefoundbutthe
5、putativeancestralpopulationhaddisappeared.Afewpatternswereeachrepresentedbyseveralsubclonesdisplayingimprovedfitness.TheseresultsofferinsightsintotheroleofISelementsintheplasticityoftheE.coligenome,andtheyfurtherdocumentthatenzyme-mediatedDNArearrangementsdooccurinrestingbacterialcultures.T
6、ABcultureskeptintightlysealedglasstubesatEightdifferentISelementsareidentifiedasresidentSroomtemperatureofferasimple,convenientonthechromosomeofE.coliK-12:IS2(OHTSUBOandmethodofstorageofbacterialstrainsforverylongpe-OHTSUBO1978);IS2(GHOSALandSAEDLER1979);IS3riods.However,itiswellknown,tomos
7、tscientistsusing(TIMMERMANandTu1985);IS4(KLAERetal.1981);IS5stabs,thatthesedonotguaranteegeneticstabilityofthe(ENGLERandBREE1981);IS30(DALRYMPLEetal.1984);storedbacterialstrains.ThisissomewhatsurprisingIS250(SCHWARTZetUl.1988),IS186(KOTHARYetUl.sinceafte
