Qhov sib txawv tseem ceeb ntawm CRISPR thiab CRISPR Cas9 yog CRISPR (clustered tsis tu ncua interspaced luv palindromic rov) yog ib txwm tshwm sim prokaryotic tiv thaiv kab mob thaum CRISPR cas9 yog RNA-guided Cas9 nuclease uas yog ib feem ntawm CRISPR adaptive. kev tiv thaiv kab mob.
CRISPR yog ib qho tshuaj tiv thaiv kab mob tiv thaiv kab mob hauv cov kab mob thiab archaea. Nws yog ib tsev neeg ntawm DNA sequences pom nyob rau hauv cov kab mob genome. Nws muaj cov kab mob sib kis uas tau los ntawm DNA tawg ntawm cov kab mob bacteriophages uas yav tas los kis rau lawv. Hauv kab mob kis kab mob tom qab, cov kab mob siv cov kab ke no los rhuav tshem cov kab mob DNA. CRISPR ib ntus muaj luv luv palindromic repeats thiab spacer sequences. Ntxiv mus, CRISPR rov ua cov kab ke sib txuas feem ntau muaj cov noob caj noob ces uas code rau Cas cov proteins. Cas9 yog RNA coj endonuclease. Ua ke nrog CRISPR ib ntus, Cas9 protein ua raws li kev tiv thaiv kab mob hauv cov kab mob tiv thaiv kab mob bacteriophages.
CRISPR yog dab tsi?
CRISPR sawv rau Clustered Regularly Interspaced Short Palindromic Repeats. Nws yog ib pawg ntawm DNA ua ntu zus pom hauv cov kab mob genome. Nws ua haujlwm raws li lub cev tiv thaiv kab mob hauv cov kab mob, thiab nws tau pom thawj zaug hauv E. coli. Hauv cov kab mob, nws ua raws li kev tiv thaiv kev tiv thaiv kab mob, tshwj xeeb tshaj yog tiv thaiv bacteriophages. Yog li ntawd, nws yog ib qho kev sib txuas lus tshwj xeeb.
Daim duab 01: CRISPR
Lub CRISPR system muaj ob peb ntu luv DNA rov ua ntu zus. Cov kev rov ua dua no yog palindromic, muaj tib lub hauv paus ua ntu zus thaum nyeem los ntawm 5' mus rau 3' thaum lwm qhov muab tib lub sijhawm thaum nyeem los ntawm 3' txog 5'. Ntxiv mus, repeats yog zoo tib yam. Lawv nyob nruab nrab ntawm luv luv "spacer" DNA sequences uas tsis zoo ib yam. Tab sis cov spacer DNA sequences zoo sib xws los yog txuam nrog txawv teb chaws bacteriophage DNA. Cov noob txuam nrog CRISPR yog hu ua CRISPR cov noob caj noob ces lossis Cas noob. Cas genes code rau Cas proteins uas yog helicases los yog nucleases. Helicases unwind DNA thaum nucleases txiav DNA. Zuag qhia tag nrho, thaum xav txog CRISPR, nws yog ib qho kev tiv thaiv kab mob ntawm cov kab mob uas ua haujlwm tawm tsam bacteriophages (cov kab mob kis kab mob).
CRISPR Cas9 yog dab tsi?
Cas9 lossis CRISPR txuam nrog protein 9 yog cov kab mob RNA-guided endonuclease. Yog li, nws yog ib qho enzyme uas paub txog thiab txiav cov hom phiaj DNA (tshwj xeeb tshaj yog cov kab mob bacteriophage DNA) ntxiv rau cov lus qhia RNA. Nws nqa tawm strand-specific cleavage. Cas9 protein yog coded los ntawm CRISPR cov noob caj noob ces. CRISPR cas9 yog RNA-guided CRISPR-Cas9 nuclease system uas tuaj yeem siv los ua RNA-programmable DNA targeting thiab kho lub platform rau genome editing, transcriptional perturbation, epigenetic modulation, thiab genome imaging. Qhov no CRISPR cas9 system yog nrov heev nyob rau hauv tam sim no genome kho tshuab.
Daim duab 02: CRISPR Cas9
Tam sim no, CRISPR/Cas9 system yog siv los hloov lossis hloov cov genome ntawm cov tsiaj nyeg los ntawm kev thim rov qab los yog ua kom muaj zog. Cov kab mob mammalian tuaj yeem teb rau CRISPR/Cas9 kho DNA so los ntawm kev siv cov txheej txheem kho. Nws tuaj yeem ua tiav los ntawm kev siv tsis yog homologous kawg koom nrog txoj kev (NHEJ) lossis homology-directed kho (HDR). Ob qho kev kho kho no coj qhov chaw los ntawm kev nthuav qhia ob-stranded so. Qhov no ua rau mammalian gene kho. NHEJ tuaj yeem ua rau ablation ntawm cov noob hloov pauv thiab tuaj yeem siv los tsim kev poob haujlwm. HDR tuaj yeem siv los qhia txog kev hloov pauv tshwj xeeb lossis qhia txog DNA ntu ntawm qhov ntev sib txawv. Tam sim no, CRISPR / Cas system yog siv rau hauv kev kho mob, biomedical, kev ua liaj ua teb thiab kev tshawb fawb.
Dab tsi yog qhov zoo sib xws ntawm CRISPR thiab CRISPR Cas9?
- Cas9 yog ib feem ntawm CRISPR Cas system.
- Crisper cas9 system yog lub cev tiv thaiv kab mob ib txwm muaj nyob hauv cov kab mob.
Qhov txawv ntawm CRISPR thiab CRISPR Cas9 yog dab tsi?
CRISPR yog pawg ntawm DNA ib ntus pom nyob rau hauv cov kab mob genome uas ua haujlwm raws li kev tiv thaiv ntuj tiv thaiv kab mob bacteriophages. Nws muaj xws li tsis tu ncua interspaced luv palindromic repeats, spacers thiab txuam genes. Hauv qhov sib piv, cas9 yog CRISPR txuam nrog protein 9, uas yog RNA coj endonuclease enzyme. Nws lees paub thiab cleaves DNA ob kab ntawm cov kab mob. Qhov tseeb, nws yog ib feem ntawm CRISPR tiv thaiv kab ke. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm CRISPR thiab CRISPR cas9.
Summary – CRISPR vs CRISPR Cas9
CRISPR Cas system yog cov kab ke tiv thaiv kab mob microbial. CRISPR yog ib pawg ntawm DNA sib lawv liag uas muaj palindromic luv luv repeats, spacer sequences thiab txuam genes. Cas9 yog ib qho Cas protein uas yog RNA coj endonuclease. CRISPR thiab Cas9 protein ua rau lub cev tiv thaiv kab mob ua haujlwm tiv thaiv kab mob bacteriophage hauv cov kab mob. Cas9 protein muaj peev xwm tshem tawm cov kab mob txawv teb chaws DNA thiab cuam tshuam rau lawv. CrRNA coj cas9 kom paub txog tus kab mob DNA. Yog li ntawd, CRISPR cas9 system yog lub cev tiv thaiv kab mob uas muaj nyob hauv cov kab mob tiv thaiv kab mob. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm CRISPR thiab CRISPR cas9.
