Isixhobo Esitsha soGwenxa lweGene
Inkqubo enokuguquguqukayo abaphandi abanokuyisebenzisa ukuguqula ngokulula imbonakalo yezakhi zofuzo ukuze baqonde kangcono umsebenzi wabo.
Yintoni eyiyo i-CRISPR?
I-CRISPR imela ngokuphindaphindiweyo ngokuphindaphindiweyo-okufakwe kwi-short Palindromic ephindaphindiweyo -gama elincinci kakhulu elincinci ngeteknoloji enomdla. Kutheni igama elibi? Kungenxa yokuba, xa beqala ukufumanisa ngasekupheleni kweminyaka yama-1980 kwiibhaktheriya, akukho mntu wayesazi ukuba i-DNA ephindaphindiweyo ye-DNA eyahlukana ngokulandelelana kwe-DNA. Ziyinto nje engaqhelekanga kwi-genomic DNA yeebhaktheriya ezithile.
Kuthatha phantse iminyaka engama-20 de kube nguJennifer Doudna kwiYunivesithi yaseCalifornia eqikelele ukuba oku kulandelelanayo kuhambelana neengxenye zeDNA ethile yentsholongwane eyenza i-bacterium. Njengoko kwavela, ukulandelelana kwe-CRISPR kwakuhlobo lwe-immune system yeebhaktheriya.
Ingaba isebenza kanjani?
UDoudna kunye nombambisene naye, u-Emmanuelle Charpentier, ekugqibeleni wenza ukuba, xa unesifo sengculaza, iibhaktheriya ezinalo zifutshane eziphindaphindiweyo zeDNA ezifana ne-DNA ye-viral ingasebenzisa ukwenza i- RNA eya kwi-DNA yegciwane elitshayo.
Emva koko, isahlulo sesibini seRNA esenziwe kwi-DNA engahleliyo eyahlula i-CRISPR iphinda iphindwe kunye neprotheni ebizwa ngokuthi i-Cas9. Le prothini iya kunamathela kwi-DNA yintsholongwane kwaye ingacwangcisi intsholongwane.
Abaphandi baqaphela ngokukhawuleza ukuba bangasebenzisa le meko ye-CRISPR ukuze banqunyulwe ukulandelelana kwe-DNA ngokuchanekileyo ukuze banqothule amajeni.
Nangona kukho ezinye iindlela, ezifana ne-zinc finger nucleases kunye ne-TALENS ezingasetyenziselwa ukujolisa nokucima indawo ezithile kwi-DNA ye-genomic, ezi ndlela zithembele kwiiprotheni ezininzi ukujolisa ukutshintshela kwimimandla ethile kwi-DNA. Kunzima ukuyila nokwenza ukuguqulwa kwinqanaba elikhulu ngeendiza ezininzi usebenzisa iindlela eziphambili.
Yintoni Eyenza Yiluncedo kangaka?
Inkqubo ye-CRISPR ixhomekeke kwiinqununu ezimbini ze-RNA: enye ehambelana nommandla we-DNA ojoliswe kuyo, kunye neyesibini ebophelela kwiprotheyini ebizwa ngokuthi i-Cas9. Enyanisweni ke, kukho ukuba zonke ezi zifutshane zeRNA zidibaniswe zibe yi - RNA -single function - guideline-molecule ye-RNA ejolise kwi-DNA ngokulandelelana kwaye ibuyise iphrotheni yokucima i-Cas9. Oku kuthetha ukuba iprotheni yeCas9 kunye ne-RNA encinane ye-RNA engama-85 esiseko eseleyo yonke into efunekayo ukunciphisa i-DNA phantse naphi na kwi-genome. Kuyinto elula ukuzisa i-DNA ukuvelisa iRNA enye-guide kunye neprotheni yeCas9 phantse nayiphi na iseli ekwenza i-CRISPR isebenza ngokubanzi.
Nangona kunjalo, ukujoliswa ngokufanelekileyo akusiyo kuphela inzuzo ye-CRISPR iteknoloji ngaphezu kwezinye i-TALENS kunye neminwe ye-zinc. Inkqubo ye-CRISPR iphinda iphumelele ngakumbi kuneendlela ezizezinye.
Ngokomzekelo, iqela laseHarvard lifumene ukuba i-CRISPR isusiwe i-gene egxile kwi-51% -79% yamatyala, kanti ukusetyenziswa kwe-TALENS kwakungaphantsi kwama-34%. Ngenxa yobu buchule obuphezulu, elinye iqela lakwazi ukusebenzisa iteknoloji ye-CRISPR ngokukhawuleza izitshizi kwiigundane zamagryon ukuvelisa iigundane ze-transgenic kwisizukulwana esinye. Indlela efunekayo idinga izizukulwana ezizalanayo zokuzalanisa ukuze zenze utshintsho kwiikopi zombini.
Yintoni Enokuyenza?
Ukongeza kokususa i-gene, amanye amaqela aye aqonda ukuba, ngezinye iinguqu ezimbalwa, inkqubo ingasetyenziselwa ezinye iintlobo zokuxhaphaza i-genetic. Ngokomzekelo, ekuqaleni kwe-2013, iqela elivela kwi-MIT libonise ukuba i-CRISPR ingasetyenziselwa ukufaka iifom ezitsha kwi-genomic DNA. Kungekudala emva kokuba iqela e-UCSF lisetyenziswe inguqu eguqulelwe yenkqubo ebizwa ngokuba yi-CRISPRi ukunyanzelisa ukubonakalisa i-genetic target in bacteria.
Ngoku kutshanje, iqela kwiYunivesithi yaseDuke liye lahlela ukutshintsha kwenkqubo ukwenzela ukuba isebenzise iiseti zegesi. Amaqela amaninzi ngoku asebenza ngokuhlukahluka kwezi ndlela zokukhusela inani elikhulu leentsholongwane ngokukhawuleza ukuba zibandakanye ukuba ngubani ochaphazelekayo kwiimpendulo ezahlukeneyo ze-biological.
I-Shiny New Toy yeJinetic Engineering
Ngokuqinisekileyo, kukho uvuyo olunzulu malunga nesi sixhobo esitsha sobunjineli bemfuza kunye nokukhawuleza ukuyisebenzisa kwizicelo ezahlukeneyo. Nangona kunjalo, kusekho imingeni efuna ukuyitshintsha kwaye, njengokuba kunjalo ngokubhekiselele kwi-teknoloji entsha, kuthatha ixesha elithile ukuba liphume apho ukulinganiselwa khona. Ngokomzekelo, abaphandi baseHarvard baye bafumanisa ukuba i-CRISPR ekujoliswe kuyo ingabi yinto echanekileyo njengoko yayicinga kuqala. Iziphumo ezingekho phantsi kwe-CRISPR ezinokubakho zingakhokelela ekutshintsheni okungafunekiyo xa kuguqulwa i-DNA.
Nangona kunjalo, imingeni, i-CRISPR ibonise ngokucacileyo amandla amakhulu okuququzelela ukuguqulwa kwe-DNA ye-genomic eya kunceda abaphandi ngokukhawuleza baqonde indlela amawaka eenkulungwane zegciwane kwi-genome function function. Le yodwa ineempembelelo ezibalulekileyo zokuphucula izifo kunye nokuxilongwa. Ukongezelela, kunye nophuhliso olongezelelweyo, iteknoloji ngokwayo inokuba luncedo kwindlela enomdla wolwazi. Inokubonelela ngeendlela ezintsha zonyango lomzimba . Nangona kunjalo, le nkqubela iyindlela yokuphuma. Okwangoku, kuyinto evuyayo ukujonga uphuhliso olukhawulezayo lweso sixhobo sophando olutsha kwaye ucinge ngeentlobo zezilingo ezingavumela.
(Kuthunyelwe: Septemba 30, 2013)