A possible cause of termination of cell growth in the cellular slime mold Dictyostelium discoideum☆
[摘要] Amacromolecularinhibitorofcelldivisioncanbewashedoffexponentiallygrowingaswellasstationaryslimemoldamoebae.However,stationarycellsappeartohavefourtimesasmuchmitoticinhibitingactivityasthesamenumberofexponentialcells.Removalofsuchaninhibitorbywashingcellsduringexponentialgrowthdelayedtheonsetofstationaryphaseandresultedincultureswithafinalcelldensitydoublethatnormallyattained.Additionofapartiallypurifiedfractionofdivisioninhibitortorapidlygrowingcellsresultsintheabruptterminationofcelldivision.Itisalsodemonstratedthatconditionedmediumcontainssufficientnutrientsforcellgrowth.Therefore,thedivisioninhibitormayplayasignificantroleinthecessationofgrowth.Proteincontentofamoebaeincreasesduringvegetativegrowth,reachingamaximumatstationaryphase.TheeffectofcyclicAMPoncelldivisionwasexamined.Ahypothesisonthemechanismofactionandadaptivesignificanceofthedivisioninhibitorisdiscussed:Amacromolecularmitoticinhibitorbeginstoaccumulateonthecellsurfaceduringvegetativegrowth.Whentheinhibitorsaturatesthecellsurface,mitosisisprevented.Thisinhibitionmayoccurthroughactivationofadenylcyclase.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
