DNA mutation, damage and repair
DNA mutation, damage and repair
DNA修复与人类生活密切相关我喝的是酒流出的是血LiFeS....FocusOnLife生活焦点辐射无处不在的健康隐形杀手！中国NSEENE2E：ARISESSETETEECORXRECEESYOKAMEN.C长期吸烟和酗酒会导致DNA损伤，削弱和抑制身体DNA修复能力紫外线照射、辐射损伤DNA
DNA修复与人类生活密切相关 长期吸烟和酗酒会导致DNA损伤，削弱和抑制身体DNA修复能力； 紫外线照射、辐射损伤DNA
DNAmutationWhatisamutation?Substitution,deletion,orinsertionofa basepairChromosomaldeletion,insertion,orrearrangementSomatic mutations occurin somatic cells and onlyaffect the individual in whichthemutationarisesGerm-line mutations alter gametes and passed to the next generation
What is a mutation? • Substitution, deletion, or insertion of a base pair. • Chromosomal deletion, insertion, or rearrangement. Somatic mutations occur in somatic cells and only affect the individual in which the mutation arises. Germ-line mutations alter gametes and passed to the next generation. DNA mutation
TypesofbasepairsubstitutionsandmutationsSequence of mutated geneSequenceofpartofanormalgeneTransitionmutation(ATtoGCinthisexample)a)转换53'5'3TCTCAAAAATTTACGTCTCAAGAATTTACG3'535'AGAGTTTTTAAATGCAGAGTTCTTAAATGCb)Transversionmutation(CGtoGCinthisexample)颠换553'3'TCTCAAAAATTTACGTCTGAAAAATTTACG5'335'AGAGTTTTTAAATGCAGACTTTTTAAATGC错义突变c)Missensemutation(changefromoneaminoacidtoanother;hereatransitionmutationfromATtoGCchangesthecodonfromlysinetoglutamicacid)5'5'33'TCTCAAAAATTTACGTCTCAAGAATTTACG3'3'5°AGAGTTTTTAAATGC5LAGAGTTCTTAAATGCSerGin Lys PheThr-SerGIn GluPheThr:无义突变dyNonsensemutation(changefromanaminoacidto astopcodon;hereatransversionmutationfromATtoTAchangesthecodonfromlysinetoUAAstopcodon)5'5'3'3'TCTCAAAAATTTACGTCTCAATAATTTACG33'55AGAGTTTTTAAATGCAGAGTTATTAAATGC..Ser Gin Lys PheThr.....SerGin Stop
Types of base pair substitutions and mutations 错义突变 无义突变 转换 颠换
Sequence of partof a normal geneSequence ofmutated geneNeutral mutation(changefromanaminoacidtoanotheramino acidwithsimilare)中性突变chemicalproperties;hereanATtoGCtransitionmutationchangesthecodonfromlysineto arginine)35'5'3TCTCAAAAATTTACGTCTCAAAGATTTACG3'535AGAGTTTTTAAATGCAGAGTTTCTAAATGC.Ser Gln Lys PheThr...Ser GlnArgPheThr同义突变(synonymousmutation）Silentmutation (change in codon suchthatthe sameamino acidisspecified;hhereanAT-to-GCtransitioninthethirdpositionofthecodongivesacodonthatstillencodeslysine)3'5'3'5TCTCAAAAATTTACGTCTCAAAAGTTTACG53'5°3'AGAGTTTTTAAATGCAGAGTTTTCAAATGCSer Gin Lys Phe Thr...SerGlnLysPheThr-Frameshiftmutation(additionordeletionofoneorafewbasepairsleadstoag)changeinreadingframe:heretheinsertionofaGCbasepairscramblesthe移码突变messageafterglutamine)5'5'3'3TCTCAAAAATTTACGTCTCAAGAAATTTACG3'355AGAGTTTTTAAATGCAGAGTTCTTTAAATGC.Ser Gin Lys PheThr.....Ser GinGluIleTyr
同义突变（ synonymous mutation） 中性突变 移码突变