Qhov Tseem Ceeb - YAC vs BAC Vectors
Vectors yog siv rau hauv molecular cloning. Ib tus vector tuaj yeem txhais tau tias yog DNA molecule uas coj zoo li lub tsheb thauj khoom txawv teb chaws mus rau lwm lub cell. Ib tug vector uas muaj DNA txawv teb chaws yog hu ua recombinant DNA thiab nws yuav tsum muaj lub peev xwm ntawm replicating thiab qhia nws nyob rau hauv lub host organism. Poov xab dag chromosome (YAC) thiab cov kab mob sib xyaw ua ke (BAC) yog ob hom vectors koom nrog hauv cloning. Qhov sib txawv tseem ceeb ntawm YAC thiab BAC yog tias YAC yog ib qho kev tsim kho vector uas siv ib cheeb tsam ntawm cov poov xab chromosome los ntxig cov khoom loj ntawm cov khoom siv caj ces rau cov poov xab thaum BAC yog ib qho kev tsim vector system siv ib cheeb tsam ntawm E.coli chromosome los ntxig ntau ntu ntawm DNA rau hauv E. coli cells.
YAC vectors yog dab tsi?
YAC (Poj niam dag chromosome) yog ib qho khoom tsim chromosome uas muaj peev xwm nqa tau ib ntu loj ntawm txawv teb chaws DNA thiab rov ua dua hauv cov poov xab. Nws muaj centromere, telomeres thiab autonomously replicating sequences uas yog ib qho tseem ceeb rau replication thiab stability. YAC tseem yuav tsum dais cov cim xaiv lossis cov cim thiab cov chaw txwv kom ua rau nws ua tau zoo cloning vector. Ib qho loj ib ntus txij li 1000 kb txog 2000 kb tuaj yeem muab tso rau hauv YAC thiab xa mus rau cov poov xab. Kev hloov pauv kev ua haujlwm ntawm YAC tsawg heev.
Daim duab 01: YAC Vector
BAC Vectors yog dab tsi?
Cov kab mob ua kom muaj chromosome (BAC) yog ib qho khoom tsim ua chromosome rau molecular cloning. Nws muaj cov cheeb tsam tshwj xeeb ntawm E. coli F plasmid thiab nws ncig thiab super coiled. BAC yog tsim los clone DNA fragments rau cov kab mob, tshwj xeeb tshaj yog rau E. coli. Nws tuaj yeem dais DNA tawg uas muaj qhov loj txog 300 kb. Piv rau YAC, BAC cloning inserts yog me dua qhov ntau thiab tsawg. BACs tau tsim nyob rau hauv 1992 thiab nws tseem nrov vim nws ruaj khov thiab yooj yim ntawm kev tsim kho. BACs kuj tseem siv tau los tsim cov tshuaj tiv thaiv.
Daim duab 02: BAC Vector hauv molecular cloning
YAC thiab BAC Vectors txawv li cas?
YAC vs BAC Vectors |
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| YAC yog ib qho kev tsim kho caj ces chromosome nrog kev siv cov poov xab DNA rau lub hom phiaj ntawm cloning. | BAC yog ib qho kev tsim kho DNA molecule siv E. coli DNA rau lub hom phiaj ntawm cloning. |
| Gender | |
| YACs tau tsim los clone cov tawg loj ntawm genomic DNA rau hauv cov poov xab. | BACs tau tsim los rau cloning loj genomic fragments rau hauv Escherichia coli. |
| Insert Length | |
| YACs tuaj yeem muaj megabase-loj genomic inserts.(1000 kb - 2000 kb). | BACs tuaj yeem nqa cov ntxig ntawm 200-300 kb lossis tsawg dua. |
| YAC DNA yog qhov nyuaj rau kev ua kom huv si thiab yuav tsum muaj kev xav siab rau kev tsim YAC vector system. | BAC yog qhov yooj yim los ntxuav kom huv si thiab tuaj yeem tsim tau yooj yim. |
| Chimerism | |
| YACs feem ntau chimeric. | BACs tsis tshua muaj chimeric. |
| kev ruaj ntseg | |
| YAC tsis ruaj khov. | BAC ruaj khov. |
| Kev hloov kho | |
| Yeast recombination yog qhov ua tau zoo heev thiab ib txwm ua haujlwm. Li no nws tuaj yeem tsim kev tshem tawm thiab lwm yam kev hloov kho hauv YAC. | E. coli recombination yog tiv thaiv thiab qhib thaum xav tau. Li no, nws txo cov kev hloov pauv tsis xav tau hauv BACs. |
| Kev kho mob | |
| Manipulating recombinant YACs feem ntau xav kom YAC hloov mus rau E. coli rau kev tswj xyuas tom ntej. Li no, nws yog ib qho kev ua haujlwm nyuaj. | BAC kev hloov pauv tshwm sim ncaj qha hauv E. coli. Yog li tsis tas yuav hloov DNA. Li no, cov txheej txheem tsis ua haujlwm nyuaj. |
Summary – YAC vs BAC Vectors
YAC tau dhau los ua cov cuab yeej tshawb fawb tseem ceeb hauv cov txheej txheem cloning vim nws muaj peev xwm los clone cov tawg loj ntawm DNA rau hauv lub cev. Txawm li cas los xij, YACs muaj ntau qhov tsis zoo li vectors xws li teeb meem kev tsim kho, chimerism, instability, thiab lwm yam. Yog li kom kov yeej cov teeb meem no, cov kws tshawb fawb tau tsim BAC vectors. BAC tau tsim los siv cov cheeb tsam tshwj xeeb ntawm E. coli chromosome. Nws yog ib qho vector ruaj khov thiab tuaj yeem tsim tau yooj yim. Txawm li cas los xij, qhov ntev ntawm DNA uas BAC tuaj yeem tuav tau txog li 20 npaug tsawg dua li ntawm YAC. Qhov no yog qhov txawv ntawm YAC thiab BAC vector systems. Niaj hnub no, BAC nyiam dua YAC hauv chav kuaj.
