Enzymes involved in DNA replication in the axolotl: I. Analysis of the forms and activities of DNA polymerase and DNA ligase during development☆

[摘要] DNApolymerasesandDNAligaseshavebeenstudiedduringdevelopmentoftheamphibian,axolotl.ThreeformsofDNApolymerase,I,II,andIII,withsedimentationcoefficientsinsucroseof9,6,and3.1S,respectively,havebeenfoundintheaxolotlegg.TheactivityofthesethreeDNApolymerasesisunchangedduringearlyembryonicdevelopment.TheactivityofDNApolymeraseIIIthenincreasessignificantly,beginningatthetailbudstage,whiletheactivityofDNApolymeraseIIincreasesatthelarvalstage.DNApolymeraseIdoesnotshowsignificantvariationsduringthistime.Onthebasisoftheircatalyticproperties,itappearsthatDNApolymerasesIandIIareα-typeDNApolymeraseswhereasDNApolymeraseIIIisaβ-typeenzyme.TwodifferentDNAligasesarefoundintheaxolotl,oneshowingasedimentationcoefficientinsucroseof8.2S(heavyform)andtheother,6S(lightform).The6SenzymeisthemajorDNAligaseactivityfoundintheeggbeforeandafterfertilization.Itsactivitythendecreasesduringembryonicdevelopment.Itcanbeobservedagain,astheonlyDNAligaseactivity,insomeadulttissues.The8.2Senzymeappearsduringthefirstdivisioncycleofthefertilizedegg,ispresentatallstagesofembryonicdevelopment,andisabsentfromtheadulttissuestested.PropertiesofthetwoDNAligasesatdifferentstagesofembryonicdevelopmenthavealsobeencompared.

[学科分类] 生物科学（综合）