two theories of aging(衰老学说)

《two theories of aging(衰老学说)》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、TwotheoriesofagingTherearefewcertainthingsinlife,andagingisoneofthemCatalog3Telomere&telomerase12Free-radicaltheoryofagingTheiroppositeanduniformityTelomere&telomerase1Atelomereisaregionofrepetitivenucleotidesequencesateachendofachromosome,whichprotectstheendofthechromosome

2、fromdeteriorationorfromfusionwithneighboringchromosomes.DiscoveryIntheearly1970s,RussiantheoristAlexeiOlovnikovfirstrecognizedthatchromosomescouldnotcompletelyreplicatetheirends.In1975–1977,ElizabethBlackburndiscoveredtheunusualnatureoftelomeres,withtheirsimplerepeatedDNAse

3、quencescomposingchromosomeends.ElizabethBlackburn,CarolGreider,andJackSzostakwereawardedthe2009NobelPrizeinPhysiologyorMedicineforthediscoveryofhowchromosomesareprotectedbytelomeresandtheenzymetelomerase5‘3‘repeatedDNAsequences5’-CCCCAACCCCAACCCCAACCCCAACCCCAA-----3’3’-GGGG

4、TTGGGGTTGGGGTTGGGGTTGGGGTT-------5’telomerechromosomeDNAtelomereTelomereendsfoldedbackstructureKnown,up-to-datetelomerenucleotidesequencesarelistedinTelomereDBwebsite.SomeknowntelomerenucleotidesequencesGroupOrganismTelomericrepeat(5'to3'towardtheend)VertebratesHuman,mouse,

5、XenopusTTAGGGFilamentousfungiNeurosporacrassaTTAGGGSlimemouldsPhysarum,DidymiumTTAGGGDictyosteliumAG(1-8)KinetoplastidprotozoaTrypanosoma,CrithidiaTTAGGGCiliateprotozoaTetrahymena,GlaucomaTTGGGGParameciumTTGGG(T/G)Oxytricha,Stylonychia,EuplotesTTTTGGGGApicomplexanprotozoaPl

6、asmodiumTTAGGG(T/C)HigherplantsArabidopsisthalianaTTTAGGGGreenalgaeChlamydomonasTTTTAGGGInsectsBombyxmoriTTAGGRoundwormsAscarislumbricoidesTTAGGCFissionyeastsSchizosaccharomycespombeTTAC(A)(C)G(1-8)BuddingyeastsSaccharomycescerevisiaeTGTGGGTGTGGTG(fromRNAtemplate)orG(2-3)(

7、TG)(1-6)T(consensus)SaccharomycescastelliiTCTGGGTGCandidaglabrataGGGGTCTGGGTGCTGCandidaalbicansGGTGTACGGATGTCTAACTTCTTCandidatropicalisGGTGTA[C/A]GGATGTCACGATCATTCandidamaltosaGGTGTACGGATGCAGACTCGCTTCandidaguillermondiiGGTGTACCandidapseudotropicalisGGTGTACGGATTTGATTAGTTATGT

8、KluyveromyceslactisGGTGTACGGATTTGATTAGGTATGTRelationshipbetweentelomerelengthandce