孟德尔式遗传分析及其扩展.ppt

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1、Chapter3Mendel’sGeneticAnalysisandExtension第三章孟德尔式遗传分析及其扩展3.1Mendel’slaws孟德尔遗传规律3.1.1Lawofsegregation分离律3.1.2Lawofindependentassortment自由组合律3.2多对相对性状杂交的遗传分析3.3二项式分布公式3.4Testsforgoodnessoffit:chi-squaretests适合度检验-卡方检验3.5Interactionamonggenes基因互作3.5.1Interactionbetweenal

2、leles等位基因间互作3.5.2Interactionbetweennon-alleles非等位基因间的相互作用3.6Genotype,phenotypeandenvironmental基因型、表型与环境Terms:C1,C2InheritedtraitPhenotypeGenotypeDominantRecessivePure-breedingCrossTestcrossBackcrossSelf-crossReversecrossHybridHomozygousHeterozygousProgenyAllelesCo-domi

3、nanceLethalViabilityMultipleallelesMonohybridcrossDihybridcrossEpistasisGametogenesisGoodness-of-fitχ2statistichypothesize3.1Mendel’slawsReasonsofchoosingpeaformaterial:stabletrue-breedingeasydistinguishablecharacteristicsselfandclosepollinationeasycountingLawofsegrega

4、tion(分离规律)Lawofindependentassortment(自由组合规律）3.1.1LawofsegregationMendelstudiedinheritanceofsevenphenotypesinpea,weconcentrateononlyoneofthese-Petalcolor红花×白花F1红花F2929株(705红/224白，接近3∶1)白花×红花与正交结果完全一致why705224F1和F2性状表现不受亲本组合方式影响PresumptionforthephenomenonproducedAsredisd

5、ominanttowhitethenF1plantshadredflowers.WhenF1plantsself-fertilizingthreedifferentclassesofgenotype,CCCcandccarepossible.Thereariseintheratio1:2:1.Thisishowthe3:1phenotypicratioisestablished.ValidationandDetection(假设的验证和杂合体的检测)Onesimpleextensionofthe3:1phenotyperatiopr

6、oducedwhenanF1individualiscrossedtothehomozygousrecessiveparent.F1canproducegameteswithdominantandrecessivealleles,andsotheprogenyofthecrosshavethedominantandrecessivephenotypeinequalnumbers,a1:1phenotyperatio.Thistypeofcrossistermedatestcross,andisusefulinanysituation

7、whereitisnecessarytodetermineifanindividualisheterozygous.Ccc8581Essenceoflawofsegregation:决定某一性状的等位基因在配子形成过程中彼此分离互不干扰，使得配子中仅含成对基因中的一个，产生数目相等的两种类型配子。Singleautosomaldominantgenedisorders:常染色体单基因显性遗传病的传递：家族性多发性结肠息肉(polypus)、先天性白内障(cataract)、短肢症、Huntington’sdisease等1460多种

8、性状。特点：双亲之一杂合态患者子女1/2得病，机率相等代代相传Singleautosomalrecessivegenedisorders:常染色体单基因隐性遗传病的传递：白化病(albinism)、侏儒症、唇裂、腭裂、Sicklece