分析細(xì)胞生物學(xué)cell division

12.312.3cellproliferation:(cellularreproduction)Theprocessthatincreasesthenumberofthecellsandproducesthedaughtercellsthroughcelldivisionwhichhavethesamegeneticinformationasthatofthemothercell.Thewholeprocessofcellgrowthandproliferationisdefinedasthecellcycle,thestagesthroughwhichacellpassesfromonecellmitosistothenext.

nucleardivision( Mitosisisaprocessofnuclearandcytokinesiswhichresultsintheoftwodaughtercellsfromasingleparentcellwithsameerphaseinterphase

metaphase,anaphase,1.Greatchanges ceinthecell mitoticapparatus(有 器)andring(收縮環(huán))nuclearenvelopeandnucleolusdisappearand2.theduplicatedchromosomesarepartitionedtwodaughtercells,andthechromosomalnumberssmadaughtercellarethesameasthatofmothersma

DNAduplicatedassemblyofduplicatedcyto

3.Amainreproduciblewayofeukaryotic

1(一phase(前期2.prometaphase(前中期3.metaphase(中期4.anaphase(后期 ophase(末期6.cytokinesis(胞

Prophase(前期Timelapse(時(shí)長):fromtheformationoftothedissolutionofthenuclearNucleus:(1)formationofthemitoticassemblyofdoubleprofilenuclearenvelopearefragmentedintonucleolus sm:twocentrosomesmovetowardoppositeendsofthecell(5.establishingthetwopoles);formtheearlymitoticapparatus---spindleMarktheendofprophase:thedissolutionthenuclear sm:formationofwholeAstralmicrotubules(星體微管):radiateoutwardfromthecentrosomeintotheregionoutsidethebodyofthespidle

Nucleus:allofthechromosomesealignedatthe sm:formawholemitotic

Kinetochoremicrotubules動(dòng)粒微管extendfromthecentrosometothechromosomesPolarmicrotubules極微管extendfromthecentrosomepastthechromosomes

mitoticapparatus:acomplexapparatusconsistsofcentrosome,spindleandNucleus:spindlemicrotubulesconnectwith

chromosome.Itisassociatedwithmovementandseparationof4.Anaphase4.Anaphase（后期Timelapse:fromthesplitofcentromeretothesisterchromatidspolesofthecellsplitandbegintheirpolewardmigrationTheprocessofchromosomesmovingtowardtwospindlepoles: (1)anaphaseA(shorteningofthekinetochoremicrotubules):thedyneinattachedtokinetochoremovetowardsthepoleendsthroughpassingalongtheshorteningofthemicrotubules2anaphaseB(twopolesmovement)A.asetofkinesinlocatedinequator maketheslidingofoverlap fromoppositepolesoveroneanotherinoppositedirections,thussegregatingthetwospindlepole;B.asetofdyneinsituatealongtheastralmicrotubulesandelongatethedistanceofspindletwopole.

polarpolarmicrotubulesoftwopoles:Timelapse:fromthechromosomesneartheirrespectivepolestotheformationofthetwodaughtercellsNucleus:thenucleusreform---the edispersedandformthechromatins;thenucleolusreappear;formthenucleusofthetwodaughtercells

cytokinesis(胞 associatedwithnucleardivition,fromanaphaseto contractilering smamembrane→formationofthecleavagefurrow Contractilering(收縮環(huán)):consistofactin(肌動(dòng)蛋白)filamentsandmyosin(肌球蛋白)filaments.Theoppositeslidingofthefilamentsofthecontractileringmakesthecellindent,thussplittingthecellintwo3Cytokinesisin meiosisCytokinesisin conception:Theprocessduringgermcellareproducedsothatdaughtercellsarewhichthenumberofchromosomespercellishalved 數(shù)三 分種 （terminal 裂 的（initial 比類 較 （intermediate GeneralDNAduplicateonetime;has

thestagesofdivisions;thechromosomalnumbersofthedaughtercellhavehalfasmuchasthatofthemothercell

primary2n

premeioticSphasegenerallytakesseveraltimeslongerthanpremitoticS

metaphase,prophase,

leptotene,zygotene

prophase,metaphaseanaphase,

assemblyofcentrosomeandsingleprofilekinetochore4SingleSingleprofileSisterachromatidwithoutkinetochoreprophaseLeptotene(細(xì)線期chromatiniscompactedtoformthefibrillarchromosomeZygotene(偶線期homologouschromosomesformthesynapsis(聯(lián)會(huì))andbivalent(二價(jià)體).synapsis:homologouschromosomesarepairedandassociatewithoneanotherinapoint

Homologouschromosome(同源 Twochromosomesresembleinshape,sizeandfunction.Oneisfrommother,anotherisfromfather. ♀ nonhomologoussister nonsisterSynaptonemalcomplex(聯(lián)會(huì)復(fù)合體SCisaladderlikestructurecomposedofLalelement(側(cè)生組分)Centralelement(組分)Transverse(橫向的)fibreBivalent:theresultofabivalentcontainsapairofhomologouschromosome

theformationofchiasma(交叉)andcrossingover(互換)aretaking ceinthenonsisterchromatidofhomologouschromo-somes(thebinationnodulesofSC);producethe 5diplotene（雙線期）homologouschromosomesmoveapartsomewhatfromeachother;chiasmasitebegintomovetotheendofchromosomediakinesis（終變期）：chromosomesarecompactedfurther;meioticspindleisassembled;disappearanceofnucleolus;breakdownofthenuclear

MetaphaseⅠ：homologouschromosomes(tetrad) alignedattheequator AnaphaseⅠ:(1)homologousseparatefromone(2)nonhomologouschromosomesophaseⅠ:producetwodaughtermetaphase anaphase

ophase 間期):assemblyofcentrosomeanddoubleprofilekinetochoreProphaseⅡ:chromatinsarecompactedtoformchromosomesMetaphaseⅡ:sisterchromatids(dyad-二分體)arealignedattheequator Prophase metaphse

AnaphaseⅡ:splittingofthecentromeresandsisterchromatidsmovetowardoppositepolesofthecell.ophaseⅡ:producefourdaughternumberofchromosomesreducein ophase2characteristicand(1)DNAduplicateone2characteristicand(1)DNAduplicateonetime;hastwocell①maintainthestabilityofgeneticmaterialbetweenparentalgenerationanddaughtergenerationnnchiasma(交叉andcrossingnn nonhomologous mothermother6partnership（配對(duì)）andseparationofhomologouschromosomes①partnershipishelpfulforthechiasmaandcrossingoverofthenonsisterchromatid，andresultingene ②chiasmaandcrossingoverareimportantforthehomologouschromosomescorrectpartnership ualNumberofThesameasthemothercellReduceinProducetheGeneticthestabilityofgenetic

3.comparemitosiswithTypeofOneOneOneNumberof 7ChromatinfibersarecompactedintorodlikeChromatinfibersarecompactedintorodlikeDuplicationDuplicationofchromatincondensation8structurestructureofcentrosome ···· polar ·9 動(dòng)粒微管的收縮和牽拉平衡， 排列kinetochorethechromosomesarealignedatthe anaphaseA:shorteningofkinechoremicrotubulesmovedaughterchromosomestowardtheirspindlepolePolarPolarmovement:elongationofpo