遺傳學新版課件 11

CHAPTER11ChromosomalRearrangementsAndChangesInChromosomeNumberReshapeEukaryoticGenomes

PartIChangesInChromosomeNumber1.CytologicalTechniquesPeripheralbloodlymphocyteculturetoanalysisofmitoticchromosome

2.PolyploidyPloidyeuploidydiploid(2n)haploid(n)polyploid(3n)polyploid(4n)

aneuploidymonosomy(2n-1)trisomy(2n+1)tetrasomy(2n+2)

ExamplesofpolyploidsChrysanthemumstrawberry(up)bananacotton(down)

Formationofunivalentandtrivalentasexualpropagation:cutting,graft,bulb

a.SterilePolyploids:Originoffertiletetraploidandhexaploid

b.FertilePolyploilds:OriginofPolyploids

c.ChromosomeDoublingRussiancytologistG.D.Karpechenkoin1920’sRadishXCabbagen=9n=92n=182n=18

Raphanobrassica4n=36

d.ExperimentalProductionofPolyploidse.g.Polyploidcotton

e.ExperimentalProductionofPolyploidsf.Tissue-SpecificPolyploidyandPolyteny

(endomitosis)e.g.polytenechromosomesinDrosophila,9roundsofreplication,500copiesproduced

PolyteneXchromosome

Homologouspolytenechromosomespair

Allthecentromerescongealintochromocenterg.Thegeneticsoftriploidytetraploidy

Tetraploidy

Amphiploidsinagriculture

a.TrisomicDaturastramonium(曼陀羅)

3.Aneuploidy

Aneuploidy:CausesandconsequencesMistakesduringmitosiscangenerateclonesofaneuploidcells

Aneuploidb.TrisomyinHumanBeingse.g.Downsyndrome(47,XX,+21)

TheOriginofDownSyndrome

ExamplesofAneuploidy

c.Monosomy

e.g.45,X---Turnersyndrome

TheCreationandUseofMonoploidplants

Deletion

PartIIChromosomeRearrangementsDuplicationInversionTranslocationTranspositionChromosomeRearrangements

a.DeletionofChromosomeSegments14-16weeks10-11weeks

AmniocentesisandChorionicBiopsy

OriginofDeletionandDetection

PhenotypicEffectsofDeletion

DeletionLoop

DeletionHeterozygoteFly:scarlet---darkredeyesMiceheterozygousfortheshaker-1mutation

Duplicationfor

region16Adeletionand

duplicationof6F-7C

b.ChromosomeDuplicationStructure,OriginandDetectionofDuplication

TheGeneticConsequenceofDuplication

c.AttachedXChromosomeLillianMorgan,1922XmXmxX+Y

↓XmXmX+Y

Homozygousforarecessivemutation(y)thatcausesthebodytobeyellowinDrosophila

Attached-Xchromosome

d.Inversions

TheOrigin,typesandphenotypiceffectsofinversiony+:DrosophilayellowgenePositionEffectsofChromosomeInversion

Inversionheterozygotesandrecombinationinhibition

e.Translocation:Reciprocaltranslocation

Reciprocaltranslocation

ANormalchromosome14ANormalchromosome21Translocation14and21

Translocation14and21TranslocationandDownsyndrome

Alternateandadjacentsegregationpatterns

RobertsonianTranslocatione.g.humanchromosome2:metacentricchr.Fromtwoacrocentricchr.ofgreatapes

RobertsonianTranslocation

TranslocationHeterozygoteHowareciprocaltranslocationhelps

causeonekindofleukemia

TranslocationandBurkitt’sLymphoma

f.TransposableElementsandTransposition

Transposableelementsinhumanandcorn

Retroposons:StructureandMovement

Transposons:StructureandMovement

TransposableElementsandInsertionMutation

TransposableElementsandChromosomeRearrangementsVariationinchromosomestructure

Deletione.g.Cri-du-cha