TK基因可編碼胸苷激酶

04July2024GeneticEngineering1DNAisthegeneticmaterialStructureandcharacteristicsofDNANucleicacidshybridizebybasepairingMutationschangethesequenceofDNAGeneticinformationcanbeprovidedbyDNAorRNATheinterruptedgeneOrganizationandcharacteristicsofinterruptedgenesThecharacteristicsofexonsandintronsGenescanbeisolatedbytheconservationofexonsSomeDNAsequencescodeformorethanoneproteinSummarize04July2024GeneticEngineering2DNA是遺傳物質(zhì)DNA結(jié)構(gòu)和特點通過堿基配對進行核酸雜交DNA的突變遺傳信息可由DNA或RNA提供斷裂基因

斷裂基因的組成和結(jié)構(gòu)外顯子和內(nèi)含子特點通過外顯子的特點可分離基因一些DNA序列可編碼一種以上蛋白本章主要內(nèi)容04July2024GeneticEngineering31.1

Introduction引言04July2024GeneticEngineering41.1

Introduction引言Figure1.2showsthebasicthemeofthischapter.AgeneisasequenceofDNAthatproducesanothernucleicacid,RNA.TheDNAhastwostrandsofnucleicacid,andtheRNAhasonlyonestrand.ThesequenceoftheRNAisdeterminedbythesequenceoftheDNA,theRNAisinturnusedtodirectproductionofaprotein.04July2024GeneticEngineering51.2DNAisthegeneticmaterialDNAisthegeneticmaterialofbacteriaDNAisthegeneticmaterialofvirusesDNAisthegeneticmaterialofanimalcells04July2024GeneticEngineering61.2DNA是遺傳物質(zhì)DNA是細菌的遺傳物質(zhì)DNA是病毒的遺傳物質(zhì)DNA是動物細胞的遺傳物質(zhì)04July2024GeneticEngineering7Background背景肺炎鏈球菌：可引起肺炎，其莢膜多糖成分可以引發(fā)毒性。其有多種變異及亞型，其中S（smooth,S）亞型的莢膜具有多糖成分，而R（rough,R）亞型由于莢膜當中缺乏多糖成分所以不會導(dǎo)致毒性。ThebacteriumPneumococcus

肺炎鏈球菌屬

killsmicebycausingpneumonia肺炎.Thesebacteriahaveasmoothtype(S)andaroughtype(R).TheStypecankillthemice,butRtypecannot.DNAisthegeneticmaterialofbacteria04July2024GeneticEngineering8EvidenceofDNAisthegeneticmaterialofbacteria04July2024GeneticEngineering9DNA是細菌的遺傳物質(zhì)證據(jù)04July2024GeneticEngineering10Avirulentmutants

無效突變ofavirushavelostthecapacity能力toinfectahostcellproductively有效的,thatis,tomakemorevirus.

Transfection

轉(zhuǎn)染ofeukaryotic

真核cellsistheacquisition

獲得ofnewgeneticmarkersbyincorporation

混合ofaddedDNA.

Transformingprinciple

轉(zhuǎn)化原理isDNAthatistakenupbyabacteriumandwhoseexpressionthenchangestheproperties

性質(zhì)oftherecipientcell.受體細胞DNAisthegeneticmaterialofvirusesSummary04July2024GeneticEngineering111.病毒的無效突變能夠有效使其喪失感染宿主細胞的能力，但不會影響其在宿主細胞復(fù)制產(chǎn)生病毒。

2.通過轉(zhuǎn)染的方式，能夠?qū)⑼庠碊NA轉(zhuǎn)入至真核細胞內(nèi)，使其獲得一個新的基因標記。

3.轉(zhuǎn)化的原理是：攜帶有新DNA的菌體在表達過程中會產(chǎn)生DNA所編碼的蛋白，從而改變原有受體細胞的表達特性，形成一個新的個體。DNA是細菌的遺傳物質(zhì)小結(jié)04July2024GeneticEngineering12DNAisthegeneticmaterialofbacteriaKeyconceptsBacterialtransformationprovidedthefirstproof

證據(jù)thatDNAisthegeneticmaterial.

Geneticproperties

遺傳特性canbetransferredfromonebacterialstrain

株（菌）toanotherbyextractingDNAfromthefirststrainandaddingittothesecondstrain.04July2024GeneticEngineering13DNA是細菌的遺傳物質(zhì)關(guān)鍵概念

細菌轉(zhuǎn)化實驗為DNA是遺傳物質(zhì)提供了重要的證據(jù)。從第一個菌株抽屜DNA,然后加入到第二個菌株中，能使遺傳特性從一個細菌菌株傳遞到另一個菌株。04July2024GeneticEngineering14BackgroundDNAisthegeneticmaterialofvirusesAttaches:吸附Injected:注入Synthesis:合成Assembly:裝配Release:釋放04July2024GeneticEngineering15EvidenceofDNAisthegeneticmaterialofviruses04July2024GeneticEngineering161.BacteriawereinfectedwithT2phages

噬菌體thathadbeenradioactively

放射性的labeled

標記eitherintheirDNAcomponent

組分(with32P)orintheirproteincomponent(with35S).

2.Mostofthe32Plabelwaspresentintheinfectedbacteriaandlessthan1%oftheproteincontained35S.DNAisthegeneticmaterialofvirusesSummary04July2024GeneticEngineering171.利用32P和35S放射性同位素分別標記T2噬菌體的基因組DNA及外殼蛋白。

2.在子代噬菌體當中發(fā)現(xiàn)約30%P放射性同位素標記物，而在外殼蛋白中只有少于1%的S放射性同位素標記。

DNA是病毒的遺傳物質(zhì)小結(jié)04July2024GeneticEngineering18DNAisthegeneticmaterialofvirusesKeyconceptsPhageinfectionprovedthatDNAisthegeneticmaterialofviruses病毒.WhentheDNAandproteincomponentsofbacteriophages噬菌體

arelabeledwithdifferentradioactiveisotopes放射性同位素,onlytheDNAistransmittedtotheprogenyphages

子代噬菌體producedbyinfectingbacteria.04July2024GeneticEngineering19DNA是病毒的遺傳物質(zhì)關(guān)鍵概念

噬菌體感染證明DNA是病毒的遺傳物質(zhì)。當細菌的DNA和蛋白組分被標記上不同的放射性同位素時，僅有DNA被傳遞到感染細菌所產(chǎn)生的子代噬菌體當中。04July2024GeneticEngineering20DNA是動物細胞的遺傳物質(zhì)Background背景

TK基因可編碼胸苷激酶，缺少TK基因的細胞自身無法合成胸苷，缺少TK基因的細胞無法在無胸苷的培養(yǎng)基中存活。

Thymidinekinase

胸苷激酶wasencoded編碼byTKgene,thecellthatlack缺少TKgencannotsurvival

存活

inabsenceof

缺乏thymidine.04July2024GeneticEngineering21Evidenceof

DNAisthegeneticmaterialofanimalcells04July2024GeneticEngineering22WhenDNAisaddedtopopulations

群體ofsingleeukaryotic

真核cellsgrowinginculture培養(yǎng)基,thenucleicacidentersthecells,andinsomeofthemresults導(dǎo)致intheproductionofnewproteins.

DNAisthegeneticmaterialofvirusesSummary04July2024GeneticEngineering23DNA是動物細胞的遺傳物質(zhì)小結(jié)

當DNA加入到培養(yǎng)生長的單一真核生物細胞群體中，核酸可以進入細胞，有一些導(dǎo)致產(chǎn)生新的蛋白質(zhì)，當使用純化的DNA時，DNA整合到細胞中可以產(chǎn)生特殊的蛋白質(zhì)。04July2024GeneticEngineering24DNAisthegeneticmaterialofanimalcellsKeyconceptsDNAcanbeusedtointroducenewgeneticfeatures

遺傳特征intoanimalcellsorwholeanimals.Thegeneralprincipleofthenatureofthegeneticmaterial,then,isthatitisalwaysnucleicacid;infact,itisDNAexceptintheRNAviruses.04July2024GeneticEngineering25DNA是動物細胞的遺傳物質(zhì)關(guān)鍵概念

利用DNA可引入新的特性給動物細胞或整個動物。原則上，遺傳物質(zhì)的本質(zhì)是核酸，事實上除了RNA病毒之外，其余生物的遺傳物質(zhì)都是DNA。04July2024GeneticEngineering261.3StructureandcharacteristicsofDNADNAisadoublehelix螺旋DNAreplication復(fù)制issemiconservative

半保留的Nucleicacidshybridize

雜交bybase

堿基pairing配對.04July2024GeneticEngineering271.3DNA的結(jié)構(gòu)及特點DNA是雙螺旋結(jié)構(gòu)DNA復(fù)制是半保留復(fù)制核酸通過堿基配對進行雜交04July2024GeneticEngineering28核酸相關(guān)基礎(chǔ)知識核酸

nucleicacid核苷酸

nucleotide核苷

nucleoside磷酸

phosphate嘌呤堿

purinebase或嘧啶堿

pyrimidinebase（堿基

base）核糖

ribose或脫氧核糖

deoxyribose（戊糖

amylsugar）04July2024GeneticEngineering2904July2024GeneticEngineering3004July2024GeneticEngineering31DNAisadoublehelix04July2024GeneticEngineering32DNA是雙螺旋結(jié)構(gòu)04July2024GeneticEngineering33DNAreplicationissemiconservativeEvidenceofDNAreplication復(fù)制issemiconservative

半保留04July2024GeneticEngineering34DNA是半保留復(fù)制BasepairingprovidesthemechanismforreplicatingDNA04July2024GeneticEngineering35ThereplicationforkistheregionofDNAinwhichthereisatransitionfromtheunwoundparentalduplextothenewlyreplicateddaughterduplexes.

DNAreplicationissemiconservativeReplicationfork復(fù)制叉04July2024GeneticEngineering36非復(fù)制區(qū)是母雙體，而打開的雙鏈部分是子雙體的復(fù)制區(qū)，母雙體在兩個復(fù)制區(qū)間的位置打開，該區(qū)域被稱之為復(fù)制叉。DNA是半保留復(fù)制04July2024GeneticEngineering371.Denaturation

變性ofDNAorRNAdescribesitsconversion

轉(zhuǎn)變fromthedouble-stranded

股（鏈）tothesingle-strandedstate情況;separation

分離ofthestrandsismostoftenaccomplished

達到byheating.

2.Hybridization

雜交isthepairingo