吉林大学《遗传学》第十三章 基因突变ppt课件.ppt

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1、第十三章基因突变GenicMutationClassificationofMutationsSpontaneous自发VersusInduced诱发MutationsGametic配子VersusSomatic体细胞MutationsOtherCategoriesofMutationGameticVersusSomaticMutationsAutosomal常染色体dominant显性mutationsAutosomalrecessive隐性mutationsX-linkedrecessivemutationsOtherCategoriesofMutationmorpholo

2、gicaltrait形态学特征Nutritional营养orbiochemicalvariationsregulatorymutations调节基因突变lethalmutations致死突变conditionalmutations条件突变(temperature-sensitivemutations)reversemutation回复突变MutationRateTherateisexceedinglylowforallorganisms生物studied;2.Therateisseentovaryconsiderablyindifferentorganisms;3.Evenw

3、ithinthesamespecies,thespontaneousmutationratevariesfromgenetogene.SpontaneousMutationRate10–8virus,bacteria,Neurospora脉孢菌10–6–10–5maize玉米,Drosophila果蝇10–5–10–4MouseInterpretationofLuria-DelbruckfluctuationexperimentandreplicaplatingBacterialresistancearisesfrommutationsthatexistbeforeexpos

4、uretoagentThebacteriocidebecomesaselectiveagentkillingthenonresistantcells,allowingonlythepreexistingresistantcellstosurvive.MutationsdonotariseinparticulargenesasadirectresponsetoenvironmentMutationsoccurrandomlyatanytimeReplicaplating平板影印试验verifiespreexistingmutationsFig.7.5bAuxotroph(营养缺

5、陷型):NeedssupplementtogrowonminimalmediaPrototroph(原养型):Wild-typethatneedsnosupplement;cansynthesizeallrequiredgrowthfactorsMutagenesisandIsolationofmutantsConidia无性孢子Ascospore囊孢子Ascus子囊AmesTestforMutagenicity测试用菌种:鼠伤寒沙门氏菌(Salmonellatyphimurium)组氨酸和生物素缺陷的突变株(His-,bio-,uvrB,rfa)His-(组氨酸缺陷突变型)

6、Rfa(细菌荚膜脂多糖屏障缺陷突变)uvrB(DNA切除修复系统缺陷突变)Apr(抗氨苄青霉素因子)S-9溶液(诱导大鼠肝脏酶系活性)TheAmestestforcarcinogensusinghis-mutantsofSalmonellatyphimuriumWhyareenzymesadded?检测突变在分子水平上的机制(1)检测诱发碱基置换诱变剂的菌株:TA1535,TA100；(2)检测诱发移码突变诱变剂的菌株:TA1537,TA1538,TA98。airandwaterpollutionfoodpreservation防腐剂andadditives添加剂artifi

7、cialsweeteners人造甜味剂herbicides(除草剂)pesticides（杀虫剂）pharmaceuticalproducts医药品四、DNA分子水平上突变的分类1、碱基替换：嘌呤替换嘌呤或嘧啶替换嘧啶（转换）；嘌呤与嘧啶互换（颠换）2、缺失3、插入4、倒位5、易位碱基的变化酮式烯醇式氨基式亚氨基式氨基式亚氨基式酮式烯醇式亚氨基式氨基式酮式烯醇式酮式5-溴尿嘧啶烯醇式5-溴尿嘧啶次黄嘌呤胞嘧啶经氧化脱氨后形成尿嘧啶和腺嘌呤配对黄嘌呤EMS(甲基磺酸乙酯)6、DNA插入剂原黄素（profl