Qhov Tseem Ceeb Qhov txawv - cDNA vs Genomic Library
Muaj ob hom tsev qiv ntawv DNA loj tsim los ntawm cov kws tshawb fawb siv cov txheej txheem kev tsim kho caj ces. Cov no yog cov tsev qiv ntawv cDNA thiab cov tsev qiv ntawv Genomic. Qhov sib txawv tseem ceeb ntawm cDNA thiab Genomic tsev qiv ntawv yog tias cDNA lub tsev qiv ntawv muaj cov cloned ntxiv DNA ntawm tag nrho cov mRNA ntawm cov kab mob thaum lub tsev qiv ntawv DNA genomic muaj cov seem cloned ntawm tag nrho cov genome ntawm cov kab mob. Lub tsev qiv ntawv DNA genomic loj dua li lub tsev qiv ntawv cDNA.
Genomic Library yog dab tsi?
Lub tsev qiv ntawv genomic DNA yog ib qho kev sau ntawm cov clones coj cov seem ntawm tag nrho cov genomic DNA ntawm cov kab mob. Nws muaj tag nrho cov genomic DNA ntawm cov kab mob no, suav nrog coding thiab noncoding sequences. Kev tsim kho lub tsev qiv ntawv genomic yog ua los ntawm cov thev naus laus zis DNA recombinant ua raws li cloning (genetic engineering). Muaj cov kauj ruam sib txawv hauv kev tsim kho raws li qhia hauv daim duab 01. Cov txheej txheem pib nrog kev cais DNA genomic. Siv cov txheej txheem DNA rho tawm tsim nyog, tag nrho cov genomic DNA ntawm cov kab mob yuav tsum raug cais tawm. Tom qab ntawd DNA yuav tsum tau hloov mus rau hauv qhov ntau thiab tsawg los yog rau hauv cov khoom tawg yooj yim los ntawm kev txwv endonucleases (DNA txiav enzymes). Fragmented DNA yuav tsum tau muab tso rau hauv vectors siv DNA ligases (DNA koom nrog enzymes). Ib tug vector yog ib tug self-replicating kab mob. Plasmids thiab bacteriophages feem ntau siv cov vectors hauv cov tshuab DNA recombinant. Cov ligated vectors no hu ua recombinant DNA molecules txij li thaum lawv nqa ob tus kheej thiab tso DNA sib lawv liag. Recombinant vectors tau ntxiv rau cov kab mob hauv tsev thiab ua kom cov kab mob rov ua dua hauv cov kab mob ntawm tes. Cov kab mob uas muaj cov kab mob sib xyaw ua ke (plasmids) yuav tsum tau loj hlob hauv kab lis kev cai nruab nrab. Thaum cov kab mob sib npaug, cov kab mob DNA, ua ke nrog cov plasmids recombinant, rov ua dua lawv cov genomes thiab tsim cov clones. Cov clones no muaj tag nrho cov genome ntawm cov kab mob hauv lub cev. Li no, nws yog hu ua lub tsev qiv ntawv genomic. Plasmids tuaj yeem yooj yim sib cais los ntawm cov kab mob chromosomal DNA los tsim lub tsev qiv ntawv genomic ntawm cov kab mob. Yog tias ib yam kab mob tshwj xeeb muaj cov noob xav tau, nws yooj yim los kuaj xyuas nws hauv lub tsev qiv ntawv genomic los ntawm kev sib xyaw ua ke siv cov tshuaj ntsuam xyuas molecular (cov cim).
Genomic tsev qiv ntawv yog ib qho tseem ceeb rau kev kawm txog cov qauv genomic thiab kev ua haujlwm, cov noob tshwj xeeb, qhov chaw nyob ntawm cov noob, kev hloov pauv, cov noob sequencing, txheeb xyuas cov tshuaj kho tshiab cov noob thiab lwm yam.
Figure_1: Kev tsim kho lub tsev qiv ntawv genomic
Lub tsev qiv ntawv cDNA yog dab tsi?
Lub tsev qiv ntawv cDNA yog ib qho kev sib sau ntawm DNA (cDNA) clones ua ke los ntawm tag nrho mRNA ntawm lub cev. Txoj kev tsim kho muaj cov kauj ruam sib txawv. Kev ua kom huv ntawm tag nrho mRNA los ntawm lub cev yog thawj kauj ruam koom nrog. Kev rho tawm mRNA raug hloov mus rau hauv cDNA strands los ntawm cov txheej txheem hu ua thim rov qab. Kev hloov pauv rov qab tau yooj yim los ntawm ib qho enzyme hu ua thim rov qab transcriptase. Nws siv lub me me 3 'primer thiab pib ua cov synthesis ntawm thawj cDNA strand complementary rau template mRNA strand. Qhov tshwm sim ob npaug cDNA raug hloov mus rau hauv cov khoom me me uas siv cov kev txwv endonucleases thiab muab tso rau hauv cov vectors tsim nyog. Cov qauv tsim ua kom rov ua dua tshiab no tom qab ntawd ntxiv rau hauv cov kab mob hauv lub cev thiab loj hlob hauv kab lis kev cai nruab nrab los tsim cov clones. Kev sau cov clones uas muaj cDNA tawg ntawm ib lub cev yog lub npe hu ua cDNA tsev qiv ntawv. Tag nrho cov hlais paub tab mRNA tsis muaj introns thiab tswj cheeb tsam. Yog li tsis yog-coding fragments tsis muaj nyob rau hauv cDNA cov tsev qiv ntawv tsis zoo li hauv lub tsev qiv ntawv genomic.
cDNA cov tsev qiv ntawv yog qhov tseem ceeb rau kev tsom xam ntawm cheeb tsam coding, gene functions, qhia cov noob thiab lwm yam.
Figure_2: Kev tsim kho lub tsev qiv ntawv cDNA
Dab tsi yog qhov txawv ntawm cDNA thiab Genomic Library?
cDNA vs Genomic Library |
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| cDNA tsev qiv ntawv yog ib phau ntawm cov clones uas muaj cov DNA ntxiv rau mRNA ntawm cov kab mob | Genomic library yog ib phau ntawm cov clones bearing tag nrho genomic DNA ntawm ib yam kabmob. |
| Coding vs Noncoding Sequences | |
| cDNA tsev qiv ntawv tsuas muaj cov coding sequences xwb; nws tsis muaj introns. | Genomic library muaj tag nrho cov DNA genomic nrog rau noncoding (introns thiab tswj) DNA. |
| cDNA tsev qiv ntawv me me. | Genomic library loj. |
| Starting Material | |
| khoom pib yog mRNA | Cov khoom pib yog DNA. |
| Kev koom tes ntawm Kev Hloov Rov Qab. | |
| Reverse transcription tshwm sim hauv thawj cDNA strand synthesis. | Kev hloov pauv tsis tshwm sim. |
Summary – cDNA thiab Genomic Library
Lub tsev qiv ntawv genomic sawv cev rau cov pej xeem ntawm cov clones uas muaj qhov tawg tag nrho cov genomic DNA ntawm cov kab mob. cDNA lub tsev qiv ntawv sawv cev rau cov pej xeem ntawm clones bearing complementary DNA ntawm tag nrho mRNA ntawm ib tug kab mob. Lub cDNA clone tsuas muaj cov kab ke pom hauv mRNA thaum lub genomic clone muaj cov kab ke ntawm tag nrho cov genome. Qhov no yog qhov txawv ntawm cDNA thiab genomic library.
