動物遺傳學課件

Chapter8Geneticstructureinanimalpopulation

動物群體的遺傳結構TheHardy-Weinbergequilibriuminanimalpopulations動物群體的平衡Changesinthegeneticstructureofpopulations影響平衡和基因頻率變化的因素Geneticdiversity遺傳多樣性Speciesandspeciation

物種與物種形成Populationandpopulationgenetics

群體與群體遺傳學Population:entiregroupoforganismsofonekind;aninterbreedinggroupofplantsandanimals;theextensivegroupfromwhichasamplemightbetaken.群體是由交配和親子關系相連的個體構成的集團Mendelianpopulation:

Anaturalinterbreedingunitofsexuallyreproducingplantsoranimalssharingacommongenepool.孟德爾群體是指能相互交配以有性方式產生個體的集團

Populationgenetics:Thebranchofgeneticsthatdealswithfrequenciesofallelesandgenotypesinbreedingpopulation.研究群體的遺傳結構及其變化規(guī)律的遺傳學就是群體遺傳學Evolutiongenetics進化遺傳學TheHardy-Weinbergequilibriuminanimalpopulations動物群體的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium基因頻率與Hardy-Weinberg平衡Calculationofallelefrequenciesinrandom-breedingpopulations

隨機交配群體基因頻率的計算TheHardy-Weinbergequilibriumforoveronelocus一個以上座位的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium

基因頻率與Hardy-Weinberg平衡Allelefrequency:Theproportionofoneallelerelativetoallallelesatalocusinapopulation一個群體內某一定等位基因的頻率叫做基因頻率，其中A1的頻率為：

x1=(2N11+N12)/(2N)=X11+X12/2

A2的頻率

x2=1-x1=X12/2+X22

AllelefrequenciesandTheHardy-Weinbergequilibrium

基因頻率與Hardy-Weinberg平衡X11=x12X12=2x1x2X22=x22

TheHardy-Weinbergprincipleofgeneticequilibiumdescribestherelationshipbetweenallelefrequenciesandgenotypefrequenciesundertheassumptionofrandommating.Thisprincipleappliestolociwithalleles,lociwithmultiplealleles,andX-linkedloci.

Randommating隨機交配

這是指在群體中一種性別的任何一個個體與其相反性別的任一個體交配的機會均等Allelefrequenciesinlociwithmultiplealleles復等位基因的基因頻率一般情況：Hardy-Weinberg平衡：xi=Xii+(1/2)∑Xiji≠jXii=xi2,Xij=2xixj

Calculationofallelefrequenciesinrandom-breedingpopulations

隨機交配群體基因頻率的計算Co-dominantorin-completeddominantalleles等顯性或不完全顯性等位基因

xi=(2nii+∑nij)/(2n)Completeddominantalleles完全顯性等位基因

x2=√nk/nSex-linkedloci伴性基因頻率的計算Forexample例子CalculateallelefrequenciesofA,B,C求出等位基因A,B,C的頻率GenotypeAABBCCABACBCTotalObserved7402612808200Expected720.524.512847200例1

一個群體中個體的血型比例是：血型ABOAB

比例0.320.150.490.04計算各等位基因的頻率。

解答

血型A,B,O分別由基因IA,IB,i控制，假定它們的頻率為x1,x2,x3，則x3=√0.49=0.7

x1+x2+x3=1,(x2+x3)2

=(1–x1)2(x2+x3)2=B+O,x1=1–√B+O=1–√0.32+0.49=1–0.9=0.1x2=1–0.1–0.7=0.2由于所以例2

1998級畜牧專業(yè)全體同學的血型比例是：血型ABOAB

比例14(0.259)10(0.185)26(0.482)4(0.074)

計算各等位基因的頻率。

AllelefrequenciesforX-linkedloci

伴性基因頻率雌性：x12+2x1x2+x22

A1A1A1A2A2A2雄性：

x1+x2

A1A2TheHardy-Weinbergequilibriumforoveronelocus

一個以上座位的平衡Changesinthegeneticstructureofpopulations

影響平衡和基因頻率變化的因素Matingsystems交配方式Selection選擇Mutation突變Geneticdrift遺傳漂變Immigration遷移Thefounder創(chuàng)始者效應ConditionsforHardy-WeinbergequilibiumHardy-Weinberg平衡的5個條件Uniforminadaptation適應性一致Bigpopulations大群體Randommating隨機交配Noimmigration無遷入與遷出Mutationinbalance突變處于平衡狀態(tài)Matingsystems交配方式Matingsystem:inbreedingandoutbreeding交配方式：近交與雜交EffectsofmatingsystemsontheHardy-Weinbergequilibium

交配方式的作用：改變基因型頻率，不改變基因頻率各種近交類型Varioustypesofconsanguineousmating近交效應Inbreeding,orconsanguieousmating,occurswherematesaregeneticallyrelatedInbreedingallowsrareallelestobecomehomozygous,anditgreatlyincreasesthelikelihoodthatrarerecessivedisorderswillappearintheoffspringofrelatedparentsSelection

選擇Selection:Differentialsurvivalandreproductionamonggenotypes;themostimportantofthefactorsthatchangeallelefrequenciesinlargepopulations選擇是基因型的非隨機差異繁殖

Melanicformofmothbistonbetulariarestingonanunpollutted,lichen-coveredtreetrunk(a).Atypicalformofthemothrestingonapolluted,soot-coveredtreetrunk(b)ThreebasicmodesofselectionandtheireffectsMutation突變A1A2uvx2=

uu+v平衡：

Mutation:AchangeintheDNAataparticularlocusinanorganism.Thetermisusedlooselytoincludepointmutationsinvolvingasinglegenechangeaswellasachromosomalchange.EffectsofmutationsonpopulationsMutationsareasourceofnewvariationSomemutationsareharmful,somearebeneficial,andsomeareneutralornearlysoExperimentshaveshownthatmost,ifnotallmutationsarepreadaptive,notpostadaptiveAmalelionwithacubhesired

Geneticdrift遺傳漂變Geneticdriftarechangesinsmallpopulations等位基因的隨機變動叫做遺傳漂變Geneticdriftoperatinginasmallpopulation.Theaallelefrequencychangesfrom0.5to0.3asaconsequenceofsamplingerrors.Thereisachancethattheaallelecouldbecomeextinct.Migration遷移Δqi=qi’–qi=m(qc–qi)AmodelofmigrationbetweenalargecontinentalpopulationandsmallislandFounderprinciple創(chuàng)始者效應AbalancebetweenselectionandmutationMutation-selectionbalanceforarecessivealleleGeneticdiversity

遺傳多樣性

遺傳多態(tài)現(xiàn)象(geneticpolymorphism)是指同一交配繁殖群體中存在兩種或兩種以上遺傳變異的類型,其中頻率最低的類型并不依靠重復突變維持。Geneticpolymorphism遺傳多態(tài)現(xiàn)象染色體多態(tài)現(xiàn)象chromosomalpolymorphismDNA多態(tài)現(xiàn)象DNApolymorphism蛋白質多態(tài)現(xiàn)象proteinpolymorphismchromosomalpolymorphism

染色體多態(tài)現(xiàn)象牛Y染色體的多態(tài)性豬銀染核仁組織區(qū)多態(tài)性結構異染色質多態(tài)性DNA多態(tài)現(xiàn)象產生的原因單個核苷酸的點突變即核苷酸的替換單一DNA序列的插入或缺失整串DNA序列的插入或缺失基因轉換DNA多態(tài)現(xiàn)象檢測的原理-RFLPs1)

2)電泳圖譜1)2)DNA多態(tài)現(xiàn)象的類型RFLP(restrictedfragmentlengthpolymorphism)RAPD(randomamplifiedpolymorphicDNA)微衛(wèi)星多態(tài)性(microsatellitepolymorphism)SSCP(singlestrandconformationpolymorphism)DSCP(doublestrandconformationpolymorphism)DNA芯片(DNAchips)Proteinpolymorphism

蛋白質多態(tài)現(xiàn)象

蛋白質多態(tài)現(xiàn)象是在蛋白質水平上存在的遺傳變異

蛋白質多態(tài)現(xiàn)象是由于構成蛋白質的多肽鏈上的氨基酸出現(xiàn)變化引起的GeneticvariationatthePgm-1locusoffruitfly分子水平下多態(tài)現(xiàn)象的維持機制選擇學說(selectiontheory)--認為雜合子優(yōu)勢維持分子水平下的多態(tài)現(xiàn)象中性學說(neutraltheory)--認為分子水平下的多態(tài)現(xiàn)象與選擇無關，是一種隨機的固定群體遺傳變異的度量

--群體的雜合性(H)Geneticdiversity遺傳多樣性Speciesandspeciation

物種與物種形成ThespeciesconceptPhenotypicorpheneticspeciesconceptBiologicalspeciesconceptModesofspeciationTheallopatricmodeofspeciationSympatricspeciation:AcontroversialmodeParapatricspeciationQuantumspeciationChapter2Mendel’sLaw:TheBasicPrinciplesofInheritance

孟德爾遺傳規(guī)律

Monohybridcrosses:Theprincipleofsegregation

Dihybridcrosses:TheprincipleofindependentassortmentExtensionsofMendel’slawsFormulatingandtestinggenetichypothesesMendelianPrinciplesinAnimalsMendel’sstudyofheredityHisparentswerefarmersinMoravia,thenapartoftheHapsbergEmpireinCentralEuropeAttheageof21,MendelleftthefarmandenteredaCatholicmonasteryinthecityofBrünnIn1847hewasordainedapriest,taughtatthelocalhighschool,takingtimeoutbetween1951and1953tostudyattheUniversityofViennaAfterreturningtoBrünn,heresumedhislifeasateachingmonkandbeganhisexperimentwithgardenpeaIn1865,MendelpresentedhisresultsbeforethelocalNaturalHistorySociety孟德爾選擇豌豆作為雜交材料的原因

豌豆的形狀和色澤極易區(qū)分和分析；豌豆為自花授粉植物，易于雜交。

Thegardenpea

Onepeculiarityofpeareproductionisthatthepetalsoftheflowerclosedowntightly,preventingpollengrainsfromenteringorleaving.Thisenforcesasystemofself-fertilization

Eachvarietyofpeasaredistinguishedbyaparticularcharacteristic.Mendel’sfocusonthesesingulardifferencesbetweenpeastrainsallowedhimtostudytheinheritanceofonetraitatatime.

Mendelsucceededbecausehefocusedhisattentiononcontrastingdifferencesbetweenplants孟德爾試驗成功的原因

前人的試驗有兩個問題：沒有對雜交子代按性狀分類計數(shù)和沒有運用統(tǒng)計分析孟德爾成功之處在于：運用假說-推理方法，注意實驗材料的選擇，引入群體分析和數(shù)量統(tǒng)計分析Monohybridcrosses:Theprincipleofsegregation分離定律

Homozygous×Homozygous

AllF1offspringareheterozygousandpurplecolor.

Ratioof1:2:1Tallanddwarfvarietiesarecrossed-fertilizedAllprogenyaretall.Tall3:Dwarf1

Mendel’sexplanationforsegregation對分離現(xiàn)象的解釋Inheritanttraitsaredeterminedbygenes遺傳性狀由基因決定Thereareapairofgenescontrollingatraitinacell體細胞中有兩個基因控制一個性狀Apairofgenesegregatefromeachotherduringtheformationofgametes在性細胞形成中成對的基因彼此分離Eachgametecarriesanallele每個性細胞含一個基因Thecombinationofgametesisrandom性細胞的結合完全隨機

PAA×aa

GametesAa

F1Aa

Eggs1/2A1/2a

sperm1/2A1/4AA1/4Aa1/2a1/4AA1/4aa1AA：2Aa：1aa

3：1Interpretation圖示解釋

GlossaryDominance:AconditioninwhichonememberofallelepairismanifestedtotheexclusionoftheotherRecessive:AtermappliedtoonememberofanalleliclackingtheabilitytomanifestitselfwhentheotherordominantmemberispresentGenesandallele:HomozygousandheterozygousGenotypeandphenotypeparental

性狀的概念

Character.Oneofthemanydetailsofstructure,form,substance,orfunctionthatmakeupanindividualorganism

有關概念

雜交（hybridization）是指具有不同遺傳性狀生物個體間的交配相對性狀即一對區(qū)分清楚的性狀，或者說是同一性狀的不同表現(xiàn)類型F1代中沒有表現(xiàn)出來的親代性狀作為隱性性狀（recessivecharacters），F(xiàn)1代仍然表現(xiàn)出來的親代性狀稱為顯性性狀（dominantcharacters）概念

顯性基因（dominantgene）即對應于顯性表現(xiàn)型的基因，如A；隱性基因（recessivegene）即對應于隱性表現(xiàn)型的基因，如a。表現(xiàn)出來的性狀，如豌豆的紫花和白花、圓型和皺型種子等叫做表現(xiàn)型（或表型）（phenotypes）；象AA、Aa、aa等表示個體遺傳構成的則叫基因型（genotypes）。在這幾種基因型中，象AA和aa兩個基因相同的稱為純合體（homozygotes），其中控制顯性性狀的aa稱為顯性純合體（homozygousdominants），控制隱性性狀的aa稱為隱性純合體（homozygousrecessives）；象Aa兩個基因不同的稱為雜合體（heterozygotes）。Testcross.Backcrosstotherecessiveparentaltype.

F1Yy×yyYellowGreen

GametesAllarey1/2y1/2yy=green1/2Y1/2Yy=yellow

ResultsofMendel’sMonohybridcrossesParentalstrainsF2progenyRatioTallplants×dwarfplantsRoundseeds×wrinkledseedsYellowseeds×greenseedsVioletflowers×whiteflowersInflatedpods×constrictedpods

Greenpods×yellowpodsAxialflowers×terminalflowers787tall,277dwarf5474round,1850wrinkled6022yellow,2001green705violet,224white882inflated,299constricted428green,152yellow651axial,207terminal2.82:12.96:13.01:13.15:12.95:12.82:13.14:1Segregationofdomesticanimals①白毛豬×白毛豬②黃羽雞×黃羽雞

白毛豬：棕毛黃羽雞：白羽雞Dihybridcrosses:Theprincipleofindependentassortment

Yellow,roundGreen,wrinkledP×Yellow,roundF1Self-fertilized

Yellow,roundGreen,roundYellow,wrinkledGreen,wrinkledF2Observed31510810132Ratio9:3:3:1孟德爾的試驗

P黃色圓?！辆G色皺粒

F1

黃色圓粒

F2

黃色圓粒綠色圓粒黃色皺粒綠色皺粒總和種子粒數(shù)31510810132556比例9：3：3：1

概念：親本有的性狀組合，叫做親本組合（parentcombination），與親本不同的新的性狀組合，叫重組合（recombination）

圖示Interpretationforindependentassortment

P黃圓YYRR×綠皺yyrr

F1

黃圓YyRr

F2

YRYryRyrYRYYRR

YYRrYyRRYyRrYrYYRrYYrrYyRrYyrryRYyRRYyRr

yyRR

yyRryrYyRrYyrryyRr

yyrr

自由組合定律的驗證

F1黃圓YyRr

綠皺yyrr

YRYryRyrF2YyRrYyrryyRryyrryr

黃圓黃皺綠圓綠皺實得種子

55514953比例

1：1：1：1ExtensionsofMendel’slaws

AllelicvariationandgenefunctionGeneaction:fromgenotypetophenotypeAllelicvariationandgenefunction顯色的不同表現(xiàn)completedominance完全顯性

incompletedominance不完全顯性codominance等顯性overdominance超顯性Incompletedominance

不完全顯性P卷羽FF×正常羽ff

F1

輕度卷羽Ff

F21/4卷羽：2/4輕度卷羽：1/4正常羽

FfFfffincompletedominance不完全顯性codominance等顯性

P紅色?！涟咨?/p>

F1

沙毛

F21/4紅色：1/2沙毛：1/4白毛overdominance超顯性白眼純合體（W/W）×野生型純合體（W+/W+）

W+W

熒光色素含量Geneticprinciplesforovertwopairsofgenes兩對以上基因的遺傳規(guī)律

Geneno.基因對數(shù)Phenotypeno.完全顯性時F2代表型數(shù)Gameteno.inF1F1代形成的配子數(shù)PossiblecombinationsF1代配子可能組合數(shù)Segregationration分離比1234..n24816..2n24816..2n392781..3n(3+1)1(3+1)2(3+1)3(3+1)4..(3+1)n

Geneaction:fromgenotypetophenotype

基因間的相互作用A-B-A-bbaaB-aabb9:3:3:112:3:110:3:39:6:19:4:315:113:312:410:69:7Complementation

互補作用

PRosePeaRRpprrPPF1Walnut胡桃冠

RrPpF29Walnut:3Pea:3Rose:1SingleR_P_rrP_R_pprrppEpistasis上位作用

PBlackmiceCCaa

WhitemiceccAA

F1GrayishCcAa

F29Grayish：3Black：4White9C_A_3C_aa3ccA_+1ccaa

Inhibition抑制作用PWhiteLeghornIICC

WhiteRockiicc

F1白羽黑斑點雞IiCc

F27白雞：6白羽黑斑點雞：3有色雞

I_cc+IIC_+iiccIiC_iiC_

Duplication重疊作用P陰囊疝公豬h1h1h2h2

正常母豬H1H1H2H2

正常公豬H1H1H2H2

外表正常母豬h1h1h2h2

F1正常H1h1H2h2

F215正常1陰囊疝公豬外表正常母豬

9H1_H2_+3H1_h2h2+3h1h1H2_1h1h1h2h2

Formulatingandtestinggenetichypotheses

孟德爾遺傳數(shù)據(jù)的統(tǒng)計處理Probability概率（self-study自學）TheChi-SquareTest適合性檢驗（self-study自學）MendelianPrinciplesinAnimals

畜禽質量性狀的遺傳方式

QuantitativetraitsandQualitativetraits

數(shù)量性狀與質量性狀Quantitativetraits數(shù)量性狀是指生物個體間連續(xù)的變異Qualitativetraits質量性狀是指生物個體間不連續(xù)的變異Classificationofqualitativetraits質量性狀的分類Variationsobservedwitheyessuchascolours,andforms用肉眼觀察到的遺傳變異，例如毛色，膚色，外形Variationsdetectedbyimmunological,biochemicalandphysicalmethods用免疫學方法，生物化學方法以及物理學方法等手段確定的變異Geneticdefectionandlethaltraits

遺傳缺陷與致死性狀Variationsobservedwitheyes–colours

肉眼觀察到的性狀—毛色

Phenotypesofhaircolorsincattlearedeterminedbymorethan20loci,inwhichtherearelocusRforredhair,locusBforblack,locusSforcolorphenotype,locusDforlightcolor,locusWhforwhite牛的毛色據(jù)認為由20多個基因座決定，這些基因座主要包括紅色基因R、黑色基因B、顏色生成基因S、稀釋基因座位D、白色基因Wh等Variationsobservedwitheyes–colours

肉眼觀察到的性狀—毛色Haircolorofswine(豬的毛色)Hairsofswineshowwhite,pureblack,brown-red,withwhitering,andetc.Phenotypesofswinehairsaredeterminedby5locisuchaslocusCforcolor,locusBforcolorphenotypes,andetc.類型有白色、純黑色、棕紅色以及白環(huán)帶、花斑和污白毛等，它們由色素合成強度基因C、色素生成基因B、色素分布部位基因A等5個基因決定Variationsobservedwitheyes–colours

肉眼觀察到的性狀—毛色Chickenfeathercolor(雞的羽色)Chickenfeathersshowwhite,black,yellow,red,silverand/orgolden,blueandbarred.Chickenfeathercolorarecontrolledby10loci.

常見的有白色、黑色、黃色、紅色、銀色或金色、蘭色及橫斑等，控制雞羽色的基因有10個Variationsobservedwitheyes--forms肉眼觀察到的性狀—形態(tài)

Cattlehorn牛角的有無受一對基因P和p控制，P無角，p有角；肩峰和胸垂也受一對基因控制，有肩峰和胸垂對無肩峰和胸垂為顯性豬的背型：垂背對直背不完全顯性Chickencreeper雞的爬行型：爬行性狀顯性，正常為隱性

Variationsdetectedbyimmunological,biochemicalandphysicalmethods

需用免疫以及生物化學或物理學方法等手段測定的性狀

Bloodgroups血型Proteinpolymorphisms蛋白質多態(tài)性DNApolymorphismsDNA多態(tài)性

Geneticdefectionandlethaltraits遺傳缺陷與致死性狀

豬：后肢麻痹、體表水腫、上皮缺損等牛：無毛、軟骨發(fā)育不全、回腸閉鎖等。Questions

1.爬行雞是由顯性基因CP所控制的，請寫出如下兩個交配組合的試驗結果中親本的基因型，并用X2法測驗后代是否符合理論比例？爬行雞×爬行雞→1972爬行雞︰955正常雞爬行雞×正常雞→1676爬行雞︰1661正常雞

2.一位養(yǎng)雞戶來信咨詢，說他的純種玫瑰冠雞群中，出現(xiàn)了幾只單冠個體，問應該怎樣純化玫瑰冠雞群？（玫瑰冠受顯性基因P決定，單冠性狀由p基因決定。）

3.Rose-combchickensmatedwithwalnut-comchickensproduced15walnut,14rose,5pea,and6single-combchicks.Determinethegenotypesoftheparents.

4.ThedominantmutationPluminthefruitflyalsocausesbrownish-purpleeyes.IsitpossibletodeterminewhetherPlumisanalleleofthebrownorpurplegenes?Chapter9InheritanceofQuantitativeTraits

動物數(shù)量性狀的遺傳Definitionofquantitativetraits數(shù)量性狀Geneticmechanismsofquantitativetraits數(shù)量性狀的遺傳機制Analysisofquantitativetraits研究數(shù)量性狀的幾個遺傳參數(shù)Inbreedingandoutbreeding近交和雜交Moleculartechniquesintheanalysisofquantitativetraits數(shù)量性狀分析的分子方法Definitionofquantitativetraits

數(shù)量性狀Qualitativetraitsandquantitativetraits質量性狀與數(shù)量性狀質量性狀--由單基因或簡單的兩對基因的互作影響的遺傳性狀，其變異是不連續(xù)的數(shù)量性狀--變異是連續(xù)的，從最小到最大的范圍內連續(xù)變動Thecasesofquantitativetraits

數(shù)量性狀—例子

Humanheight人的身高：最矮者和最高者的差異可能是40厘米或多一點

Animalbodyweight畜禽的體重：如豬的180日齡體重可能在60千克到120千克間變動Definitionofquantitativetraits

數(shù)量性狀—定義

象人的身高，體重以及家畜的大小，體重等這些性狀，其變異是連續(xù)的，描述它們只有通過測量的方法。這樣的性狀叫做數(shù)量性狀，它們的差異表現(xiàn)在量上或程度上Characteristicsofquantitativetraits研究數(shù)量性狀的方法的特點Needtobemeasured必須進行度量Statisticalanalysisisnecessary必須應用統(tǒng)計方法進行分析歸納Itshouldbestudiedunderpopulationlevels研究數(shù)量性狀以群體為對象才有意義Geneticmechanismsofquantitativetraits數(shù)量性狀的遺傳機制1908年提出多基因假說多基因假說的主要論點：數(shù)量性狀的遺傳基礎是許多基因，這類基因大多數(shù)沒有顯隱性的區(qū)別，每一對基因對性狀產生不大的影響，它們的效應是加性的，其行為符合基本的遺傳規(guī)律Effectsofmultipleloci

多基因的效應Additiveeffect加性效應是多個基因對某一性狀的共同效應是每個基因對該性狀的單獨效應的總和Dominanteffect顯性效應是由等位基因間相互作用產生的效應Epistasis上位效應是由非等位基因之間的相互作用產生的效應顯性效應和上位效應統(tǒng)稱為非加性效應(non-additiveeffect)越親遺傳現(xiàn)象P140千克×80千克F1130千克F2

＞140千克或＜80千克越親遺傳現(xiàn)象的解釋PA1A1A2A2a3a3×a1a1a2a2A3A3F1A1a1A2a2A3a3F2A1A1A2A2A3A3ora1a1a2a2a3a3Partitioningthevariance

數(shù)量性狀表型值的剖分表型值=基因型值+環(huán)境偏差P=G+E表型值=育種值+剩余值

P=A+EAnalysisofquantitativetraits

研究數(shù)量性狀的幾個遺傳參數(shù)Heritability遺傳力Repeatability重復力Geneticcorrelationcoefficients遺傳相關Heritability遺傳力

VP=VG+VE或

VP=VA+VEH2=Broad-senseheritability

h2=或h2=Narrow-senseheritability

VGVPVAVPσA2σP2Repeatability重復力

重復力是不同次生產周期之間同一性狀所能重復的程度重復力的意義re==VA+VEgVPσB2σB2+σw2Geneticcorrelationcoefficients

遺傳相關rA=

covAxAy遺傳相關的意義

σAxσAyInbreedingandoutbreeding

近交和雜交近交--是完全的或不完全的同型交配。相同基因型的交配叫同型交配Inbreedingdepression雜交--兩個基因型不同的純合子之間的交配Heterosis近交的效應-增加純合基因對的數(shù)目近交使基因型純合，雜交使基因型雜合近交降低群體均值，雜交提高群體均值近交使群體分化，雜交使群體一致近交加選擇能加大群體間基因頻率，從而提高雜種優(yōu)勢Heterosis雜種優(yōu)勢

兩個親本雜交，子一代個體的某一數(shù)量性狀并不等于兩個親本的平均，而是高于親本的平均，甚至超出親本范圍，比兩個親本都高，叫做雜種優(yōu)勢。表現(xiàn)在生活力，繁殖力，抗逆性以及產量和品質上雜種優(yōu)勢的解釋生活力假說Thedominancehypothesis顯性學說Theoverdominancehypothesis超顯性學說Moleculartechniquesintheanalysisofquantitativetraits

數(shù)量性狀分析的分子方法Genelociresponsibleforquantitativetraitsarecalledquantitativetraitloci(QTLs)MappingQTLshasbecomemorefeasiblewiththeadventoftechniquestodetectmolecularvariationChapter6Regulationofgeneexpression

基因表達調控Fromgenestocharacters從基因至性狀的過程Regulationofgeneexpressioninprokaryotes原核生物基因表達的調節(jié)Regulationofgeneexpressionineukaryotes真核生物基因表達的調節(jié)GenesCharacters基因性狀Characters性狀Genes基因Environment環(huán)境DNAmRNAProtein蛋白質Fromgenestocharacters

從基因至性狀的過程Theconception:onegeneonepeptide一個基因一條多肽鏈的概念Geneticcontrolsofmetabolism代謝作用的遺傳控制Variationsingeneactionandphenocopies基因效應的變異與擬表型一個基因一種障礙物

一個基因一種酶一個基因一條多肽鏈Theconception:onegeneonepeptide

一個基因一條多肽鏈的概念底物中間產物1中間產物2產物酶A酶B酶C基因A基因B基因CGeneticcontrolsofmetabolism

代謝作用的遺傳控制Variationsingeneactionandphenocopies基因效應的變異與擬表型Expressivity:Degreeofexpressionofatraitcontrolledbygene.Aparticulargenemayproducedifferentdegreesofexpressionindifferentindividuals表現(xiàn)度：某一基因型表達的程度。Penetrance:Thepercentageofindividualsthatshowaparticularphenotypeamongthosecapableofshowingit.外顯率：表現(xiàn)某一特定表型個體的比例。Phenocopy:Anorganismwhosephenotype(butnotgenotype)hasbeenchangedbytheenvironmenttoresemblethephenotypeofdifferent(mutant)organism擬表型：環(huán)境因素有時引起非遺傳的表型變化。Regulationofgeneexpressioninprokaryotes原核生物基因表達的調節(jié)Anabbreviatedpathwayofgeneexpressioninprokaryotes簡述Operons:coordinatelyregulatedunitsofgeneexpression操縱子學說ThelactoseoperoninE.coli

大腸桿菌乳糖操縱子Anabbreviatedpathwayofgeneexpressioninprokaryotes簡述Levelsatwhichgeneexpressionisregulatedinprokaryotes

3.RNAstability1.Transcription2.RNAprocessing4.Translation5.PosttranlationDNARNAtranscriptmRNAProteinFunctionperformedbyproteinOperons:coordinatelyregulatedunitsofgeneexpression操縱子學說SG1SG2SG3P1RP2OOperonStructuralgenesP1:promoterforregulatorgene;R:regulatorgene;P2:promoterforoperon;O:operatorRepressorEffectormoleculeThelactoseoperoninE.coli大腸桿菌乳糖操縱子(JacobandMonod,1961)POZY調節(jié)基因控制位點結構基因啟動區(qū)操縱區(qū)-半乳糖苷酶轉乙酰酶ZYRepression阻遏阻遏蛋白操縱區(qū)POInduction誘導+誘導物-阻遏蛋白復合物不能結合-半乳糖苷酶轉乙酰酶乳糖滲透酶Regulationofgeneexpressionineukaryotes真核生物基因表達的調節(jié)Spatialandtemporalregulationofeukaryoticgenes真核基因的時空調控Waysofregulatingeukaryoticgeneexpression真核基因表達調控的途徑Inductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors環(huán)境和生物因子誘導的轉錄活性Molecularcontroloftranscriptionineukaryotes真核轉錄的分子控制Geneexpressionandchromosomeorganization基因表達和染色體結構Activationandinactivationofwholechromosomes整條染色體的激活和失活Geneexpressionandcancer基因表達和癌癥Spatialandtemporalregulationofeukaryoticgenes真核基因的時空調控01020304050kbTimeofexpressionEmbryoFetusAdultUnknownPseudogeneOrganizationandtemporallyspecificexpressionofthehumanglobingenesWaysofregulatingeukaryoticgeneexpression真核基因表達調控的途徑ControlledtranscriptionofDNADNA控制性轉錄AlternateSplicingofRNARNA剪接

CytoplasmiccontrolofmessengerRNAstability信息RNA穩(wěn)定性胞質調控nucleusDNARNAmRNAPolypeptideTranscriptionProcessingTranslationCytoplasmInductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors環(huán)境和生物因子誘導的轉錄活性Temperature:Theheat-shockgenes溫度：熱激基因Light:Theribulose1,5-bisphosphatecarboxylasegenesinplants光：植物的核糖體1，5-二磷酸羧基酶基因Signalmolecules:Genesthatrespondtohormones信號分子：與激素反應的基因Molecularcontroloftranscriptionineukaryotes真核轉錄的分子控制DNAsequencesinvolvedinthecontroloftranscription:enhancersandsilencers參與轉錄調控的DNA序列：增強子和沉默子Proteinsinvolvedinthecontroloftranscription:transcriptionfactors參與轉錄調控的蛋白質：轉錄因子5’3’Enhancersexon1intron1exon2intron2exon3

5’3’Enhancersexon1intron1exon2intron2exon3

Geneexpressionandchromosomeorganization基因表達和染色體結構Transcriptioninlampbrushchromosomeloops燈刷染色體的轉錄Transcriptioninpolytenechromosomepuffs多線染色體膨突的轉錄MolecularorganizationoftranscriptionallyactiveDNA轉錄活躍DNA的分子構造Euchromatinandheterochomatin常染色體和異染色體Geneamplification基因擴張Transcriptioninlampbrushchromosomeloops燈刷染色體的轉錄Activationandinactivationofwholechromosomes

整條染色體的激活和失活InactivationofXchromosomesinmammals哺乳類動物X染色體的失活HyperactivationofXchromosomesinDrosophila果蠅X染色體的高度活性HypoactivationofXchromosomesinCaenorhabditisCaenorhabditis的X染色體亞活性Geneexpressionandcancer

基因表達和癌癥Tumor-inducingretrovirusesandviraloncogenus腫瘤反向病毒和病毒原癌基因Cellularhomologsofviraloncogenes:Theproto-oncogenes病毒原癌基因的細胞同源物：前原癌基因Chapter7GeneticManipulation

遺傳操作DNAmanipulationDNA的遺傳操作BasictechniquesusedtoclonegenesConstructionandscreeningofgenomiclibrariesThemanipulationofclonedDNAsequencesinvitroThemolecularanalysisofDNACellmanipulation細胞的遺傳操作HumangenetherapyTransgenicanimalsDNAmanipulationDNA的遺傳操作RecombinantDNAtechniques目的基因(thegeneofinterest)的獲取目的基因與載體結合成重組DNA重組DNA分子引入受體細胞并表達轉化體細胞的擴增、鑒定與篩選BasictechniquesusedtoclonegenesThediscoveryofrestrictionendonucleases限制性核酸內切酶TheproductionofrecombinantDNAmoleculesinvitro

AmplificationofrecombinantDNAmoleculesincloningvectorsRestrictionendonucleases

限制性核酸內切酶限制與修飾作用限制性核酸內切酶restrictionendonucleasesE.coliKE.