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动物学研究 2012
Stage-specificappearanceofcytoplasmicmicrotubulesaroundthesurvivingnucleiduringthethirdprezygoticdivisionofParameciumDOI: 10.3724/SP.J.1141.2012.E05-06E98, PP. 98-103 Keywords: Paramecium,Conjugation,Meiosis,Paroralconeregion,Cytoplasmicmicrotubules Abstract: TherearesixmicronucleardivisionsduringconjugationofParameciumcaudatum:threeprezygoticandthreepostzygoticdivisions.Fourhaploidnucleiareformedduringthefirsttwomeioticprezygoticdivisions.Usuallyonlyonemeioticproductislocatedintheparoralcone(PC)regionatthecompletionofmeiosis,whichsurvivesanddividesmitoticallytocompletethethirdprezygoticdivisiontoyieldastationaryandamigratorypronucleus.TheremainingthreelocatedoutsideofthePCdegenerate.Themigratorypronucleiarethenexchangedbetweentwoconjugantsandfusewiththestationarypronucleitoformsynkarya,whichundergothreesuccessivedivisions(postzygoticdivisions).However,littleisknownaboutthesurvivingmechanismofthePCnuclei.Inthecurrentstudy,stage-specificappearanceofcytoplasmicmicrotubules(cMTs)wasindicatedduringthethirdprezygoticdivisionbyimmunofluorescencelabelingwithanti-alphatubulinantibodiessurroundingthesurvivingnuclei,includingthePCnucleiandthetwotypesofprospectivepronuclei.ThissuggestedthatcMTswereinvolvedintheformationofaphysicalbarrier,whosefunctionmayrelatetosequesteringandprotectingthesurvivingnucleifromthemajorcytoplasm,wheredegenerationofextra-meioticproductsoccurs,anotherimportantnucleareventduringthethirdprezygoticdivision.
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