動(dòng)物遺傳學(xué)課件

Chapter8Geneticstructureinanimalpopulation

動(dòng)物群體的遺傳結(jié)構(gòu)TheHardy-Weinbergequilibriuminanimalpopulations動(dòng)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(xué)Population:entiregroupoforganismsofonekind;aninterbreedinggroupofplantsandanimals;theextensivegroupfromwhichasamplemightbetaken.群體是由交配和親子關(guān)系相連的個(gè)體構(gòu)成的集團(tuán)Mendelianpopulation:

Anaturalinterbreedingunitofsexuallyreproducingplantsoranimalssharingacommongenepool.孟德爾群體是指能相互交配以有性方式產(chǎn)生個(gè)體的集團(tuán)

Populationgenetics:Thebranchofgeneticsthatdealswithfrequenciesofallelesandgenotypesinbreedingpopulation.研究群體的遺傳結(jié)構(gòu)及其變化規(guī)律的遺傳學(xué)就是群體遺傳學(xué)Evolutiongenetics進(jìn)化遺傳學(xué)TheHardy-Weinbergequilibriuminanimalpopulations動(dòng)物群體的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium基因頻率與Hardy-Weinberg平衡Calculationofallelefrequenciesinrandom-breedingpopulations

隨機(jī)交配群體基因頻率的計(jì)算TheHardy-Weinbergequilibriumforoveronelocus一個(gè)以上座位的平衡AllelefrequenciesandTheHardy-Weinbergequilibrium

基因頻率與Hardy-Weinberg平衡Allelefrequency:Theproportionofoneallelerelativetoallallelesatalocusinapopulation一個(gè)群體內(nèi)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(jī)交配

這是指在群體中一種性別的任何一個(gè)個(gè)體與其相反性別的任一個(gè)體交配的機(jī)會(huì)均等Allelefrequenciesinlociwithmultiplealleles復(fù)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(jī)交配群體基因頻率的計(jì)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(jì)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(gè)群體中個(gè)體的血型比例是：血型ABOAB

比例0.320.150.490.04計(jì)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(jí)畜牧專業(yè)全體同學(xué)的血型比例是：血型ABOAB

比例14(0.259)10(0.185)26(0.482)4(0.074)

計(jì)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(gè)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(yīng)ConditionsforHardy-WeinbergequilibiumHardy-Weinberg平衡的5個(gè)條件Uniforminadaptation適應(yīng)性一致Bigpopulations大群體Randommating隨機(jī)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(yīng)Inbreeding,orconsanguieousmating,occurswherematesaregeneticallyrelatedInbreedingallowsrareallelestobecomehomozygous,anditgreatlyincreasesthelikelihoodthatrarerecessivedisorderswillappearintheoffspringofrelatedparentsSelection

選擇Selection:Differentialsurvivalandreproductionamonggenotypes;themostimportantofthefactorsthatchangeallelefrequenciesinlargepopulations選擇是基因型的非隨機(jī)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(jī)變動(dòng)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(yīng)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(fù)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(zhì)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(jié)構(gòu)異染色質(zhì)多態(tài)性DNA多態(tài)現(xiàn)象產(chǎn)生的原因單個(gè)核苷酸的點(diǎn)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(zhuǎn)換DNA多態(tài)現(xiàn)象檢測(cè)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(zhì)多態(tài)現(xiàn)象

蛋白質(zhì)多態(tài)現(xiàn)象是在蛋白質(zhì)水平上存在的遺傳變異

蛋白質(zhì)多態(tài)現(xiàn)象是由于構(gòu)成蛋白質(zhì)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(jī)制選擇學(xué)說(selectiontheory)--認(rèn)為雜合子優(yōu)勢(shì)維持分子水平下的多態(tài)現(xiàn)象中性學(xué)說(neutraltheory)--認(rèn)為分子水平下的多態(tài)現(xiàn)象與選擇無關(guān)，是一種隨機(jī)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(yàn)成功的原因

前人的試驗(yàn)有兩個(gè)問題：沒有對(duì)雜交子代按性狀分類計(jì)數(shù)和沒有運(yùn)用統(tǒng)計(jì)分析孟德爾成功之處在于：運(yùn)用假說-推理方法，注意實(shí)驗(yàn)材料的選擇，引入群體分析和數(shù)量統(tǒng)計(jì)分析Monohybridcrosses:Theprincipleofsegregation分離定律

Homozygous×Homozygous

AllF1offspringareheterozygousandpurplecolor.

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

Mendel’sexplanationforsegregation對(duì)分離現(xiàn)象的解釋Inheritanttraitsaredeterminedbygenes遺傳性狀由基因決定Thereareapairofgenescontrollingatraitinacell體細(xì)胞中有兩個(gè)基因控制一個(gè)性狀A(yù)pairofgenesegregatefromeachotherduringtheformationofgametes在性細(xì)胞形成中成對(duì)的基因彼此分離Eachgametecarriesanallele每個(gè)性細(xì)胞含一個(gè)基因Thecombinationofgametesisrandom性細(xì)胞的結(jié)合完全隨機(jī)

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(guān)概念

雜交（hybridization）是指具有不同遺傳性狀生物個(gè)體間的交配相對(duì)性狀即一對(duì)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(duì)應(yīng)于顯性表現(xiàn)型的基因，如A；隱性基因（recessivegene）即對(duì)應(yīng)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(gè)體遺傳構(gòu)成的則叫基因型（genotypes）。在這幾種基因型中，象AA和aa兩個(gè)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(gè)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(yàn)

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(yàn)證

F1黃圓YyRr

綠皺yyrr

YRYryRyrF2YyRrYyrryyRryyrryr

黃圓黃皺綠圓綠皺實(shí)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(duì)以上基因的遺傳規(guī)律

Geneno.基因?qū)?shù)Phenotypeno.完全顯性時(shí)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(bǔ)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(diǎn)雞IiCc

F27白雞：6白羽黑斑點(diǎn)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(jì)處理Probability概率（self-study自學(xué)）TheChi-SquareTest適合性檢驗(yàn)（self-study自學(xué)）MendelianPrinciplesinAnimals

畜禽質(zhì)量性狀的遺傳方式

QuantitativetraitsandQualitativetraits

數(shù)量性狀與質(zhì)量性狀Quantitativetraits數(shù)量性狀是指生物個(gè)體間連續(xù)的變異Qualitativetraits質(zhì)量性狀是指生物個(gè)體間不連續(xù)的變異Classificationofqualitativetraits質(zhì)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(xué)方法，生物化學(xué)方法以及物理學(xué)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(rèn)為由20多個(gè)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(qiáng)度基因C、色素生成基因B、色素分布部位基因A等5個(gè)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(gè)Variationsobservedwitheyes--forms肉眼觀察到的性狀—形態(tài)

Cattlehorn牛角的有無受一對(duì)基因P和p控制，P無角，p有角；肩峰和胸垂也受一對(duì)基因控制，有肩峰和胸垂對(duì)無肩峰和胸垂為顯性豬的背型：垂背對(duì)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(xué)或物理學(xué)方法等手段測(cè)定的性狀

Bloodgroups血型Proteinpolymorphisms蛋白質(zhì)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(qǐng)寫出如下兩個(gè)交配組合的試驗(yàn)結(jié)果中親本的基因型，并用X2法測(cè)驗(yàn)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(gè)體，問應(yīng)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(dòng)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(jī)制Analysisofquantitativetraits研究數(shù)量性狀的幾個(gè)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(zhì)量性狀與數(shù)量性狀質(zhì)量性狀--由單基因或簡單的兩對(duì)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(nèi)連續(xù)變動(dòng)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(diǎn)

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(dòng)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(cè)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(diǎn)Needtobemeasured必須進(jìn)行度量Statisticalanalysisisnecessary必須應(yīng)用統(tǒng)計(jì)方法進(jìn)行分析歸納Itshouldbestudiedunderpopulationlevels研究數(shù)量性狀以群體為對(duì)象才有意義Geneticmechanismsofquantitativetraits數(shù)量性狀的遺傳機(jī)制1908年提出多基因假說多基因假說的主要論點(diǎn)：數(shù)量性狀的遺傳基礎(chǔ)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(duì)基因?qū)π誀町a(chǎn)生不大的影響，它們的效應(yīng)是加性的，其行為符合基本的遺傳規(guī)律Effectsofmultipleloci

多基因的效應(yīng)Additiveeffect加性效應(yīng)是多個(gè)基因?qū)δ骋恍誀畹墓餐?yīng)是每個(gè)基因?qū)υ撔誀畹膯为?dú)效應(yīng)的總和Dominanteffect顯性效應(yīng)是由等位基因間相互作用產(chǎn)生的效應(yīng)Epistasis上位效應(yīng)是由非等位基因之間的相互作用產(chǎn)生的效應(yīng)顯性效應(yīng)和上位效應(yīng)統(tǒng)稱為非加性效應(yīng)(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(gè)遺傳參數(shù)Heritability遺傳力Repeatability重復(fù)力Geneticcorrelationcoefficients遺傳相關(guān)Heritability遺傳力

VP=VG+VE或

VP=VA+VEH2=Broad-senseheritability

h2=或h2=Narrow-senseheritability

VGVPVAVPσA2σP2Repeatability重復(fù)力

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

遺傳相關(guān)rA=

covAxAy遺傳相關(guān)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(gè)基因型不同的純合子之間的交配Heterosis近交的效應(yīng)-增加純合基因?qū)Φ臄?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(shì)Heterosis雜種優(yōu)勢(shì)

兩個(gè)親本雜交，子一代個(gè)體的某一數(shù)量性狀并不等于兩個(gè)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(gè)親本都高，叫做雜種優(yōu)勢(shì)。表現(xiàn)在生活力，繁殖力，抗逆性以及產(chǎn)量和品質(zhì)上雜種優(yōu)勢(shì)的解釋生活力假說Thedominancehypothesis顯性學(xué)說Theoverdominancehypothesis超顯性學(xué)說Moleculartechniquesintheanalysisofquantitativetraits

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

基因表達(dá)調(diào)控Fromgenestocharacters從基因至性狀的過程Regulationofgeneexpressioninprokaryotes原核生物基因表達(dá)的調(diào)節(jié)Regulationofgeneexpressionineukaryotes真核生物基因表達(dá)的調(diào)節(jié)GenesCharacters基因性狀Characters性狀Genes基因Environment環(huán)境DNAmRNAProtein蛋白質(zhì)Fromgenestocharacters

從基因至性狀的過程Theconception:onegeneonepeptide一個(gè)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(yīng)的變異與擬表型一個(gè)基因一種障礙物

一個(gè)基因一種酶一個(gè)基因一條多肽鏈Theconception:onegeneonepeptide

一個(gè)基因一條多肽鏈的概念底物中間產(chǎn)物1中間產(chǎn)物2產(chǎn)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(yīng)的變異與擬表型Expressivity:Degreeofexpressionofatraitcontrolledbygene.Aparticulargenemayproducedifferentdegreesofexpressionindifferentindividuals表現(xiàn)度：某一基因型表達(dá)的程度。Penetrance:Thepercentageofindividualsthatshowaparticularphenotypeamongthosecapableofshowingit.外顯率：表現(xiàn)某一特定表型個(gè)體的比例。Phenocopy:Anorganismwhosephenotype(butnotgenotype)hasbeenchangedbytheenvironmenttoresemblethephenotypeofdifferent(mutant)organism擬表型：環(huán)境因素有時(shí)引起非遺傳的表型變化。Regulationofgeneexpressioninprokaryotes原核生物基因表達(dá)的調(diào)節(jié)Anabbreviatedpathwayofgeneexpressioninprokaryotes簡述Operons:coordinatelyregulatedunitsofgeneexpression操縱子學(xué)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(xué)說SG1SG2SG3P1RP2OOperonStructuralgenesP1:promoterforregulatorgene;R:regulatorgene;P2:promoterforoperon;O:operatorRepressorEffectormoleculeThelactoseoperoninE.coli大腸桿菌乳糖操縱子(JacobandMonod,1961)POZY調(diào)節(jié)基因控制位點(diǎn)結(jié)構(gòu)基因啟動(dòng)區(qū)操縱區(qū)-半乳糖苷酶轉(zhuǎn)乙酰酶ZYRepression阻遏阻遏蛋白操縱區(qū)POInduction誘導(dǎo)+誘導(dǎo)物-阻遏蛋白復(fù)合物不能結(jié)合-半乳糖苷酶轉(zhuǎn)乙酰酶乳糖滲透酶Regulationofgeneexpressionineukaryotes真核生物基因表達(dá)的調(diào)節(jié)Spatialandtemporalregulationofeukaryoticgenes真核基因的時(shí)空調(diào)控Waysofregulatingeukaryoticgeneexpression真核基因表達(dá)調(diào)控的途徑Inductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors環(huán)境和生物因子誘導(dǎo)的轉(zhuǎn)錄活性Molecularcontroloftranscriptionineukaryotes真核轉(zhuǎn)錄的分子控制Geneexpressionandchromosomeorganization基因表達(dá)和染色體結(jié)構(gòu)Activationandinactivationofwholechromosomes整條染色體的激活和失活Geneexpressionandcancer基因表達(dá)和癌癥Spatialandtemporalregulationofeukaryoticgenes真核基因的時(shí)空調(diào)控01020304050kbTimeofexpressionEmbryoFetusAdultUnknownPseudogeneOrganizationandtemporallyspecificexpressionofthehumanglobingenesWaysofregulatingeukaryoticgeneexpression真核基因表達(dá)調(diào)控的途徑ControlledtranscriptionofDNADNA控制性轉(zhuǎn)錄AlternateSplicingofRNARNA剪接

CytoplasmiccontrolofmessengerRNAstability信息RNA穩(wěn)定性胞質(zhì)調(diào)控nucleusDNARNAmRNAPolypeptideTranscriptionProcessingTranslationCytoplasmInductionoftranscriptionalactivitybyenvironmentalandbiologicalfactors環(huán)境和生物因子誘導(dǎo)的轉(zhuǎn)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(hào)分子：與激素反應(yīng)的基因Molecularcontroloftranscriptionineukaryotes真核轉(zhuǎn)錄的分子控制DNAsequencesinvolvedinthecontroloftranscription:enhancersandsilencers參與轉(zhuǎn)錄調(diào)控的DNA序列：增強(qiáng)子和沉默子Proteinsinvolvedinthecontroloftranscription:transcriptionfactors參與轉(zhuǎn)錄調(diào)控的蛋白質(zhì)：轉(zhuǎn)錄因子5’3’Enhancersexon1intron1exon2intron2exon3

5’3’Enhancersexon1intron1exon2intron2exon3

Geneexpressionandchromosomeorganization基因表達(dá)和染色體結(jié)構(gòu)Transcriptioninlampbrushchromosomeloops燈刷染色體的轉(zhuǎn)錄Transcriptioninpolytenechromosomepuffs多線染色體膨突的轉(zhuǎn)錄MolecularorganizationoftranscriptionallyactiveDNA轉(zhuǎn)錄活躍DNA的分子構(gòu)造Euchromatinandheterochomatin常染色體和異染色體Geneamplification基因擴(kuò)張Transcriptioninlampbrushchromosomeloops燈刷染色體的轉(zhuǎn)錄Activationandinactivationofwholechromosomes

整條染色體的激活和失活I(lǐng)nactivationofXchromosomesinmammals哺乳類動(dòng)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(dá)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(xì)胞同源物：前原癌基因Chapter7GeneticManipulation

遺傳操作DNAmanipulationDNA的遺傳操作BasictechniquesusedtoclonegenesConstructionandscreeningofgenomiclibrariesThemanipulationofclonedDNAsequencesinvitroThemolecularanalysisofDNACellmanipulation細(xì)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(jié)合成重組DNA重組DNA分子引入受體細(xì)胞并表達(dá)轉(zhuǎn)化體細(xì)胞的擴(kuò)增、鑒定與篩選BasictechniquesusedtoclonegenesThediscoveryofrestrictionendonucleases限制性核酸內(nèi)切酶TheproductionofrecombinantDNAmoleculesinvitro

AmplificationofrecombinantDNAmoleculesincloningvectorsRestrictionendonucleases

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