Ukuhlelwa kofuzo okuhlelekayo: Usesho lokuhlelwa kofuzo okunembayo okuphezulu

• About the Author:
• Igama lomlobi

  I-Quantumrun Foresight
• December 19, 2022

Isifinyezo sokuqonda

Ukuhlela izakhi zofuzo kuholele ekutholweni okujabulisayo kwezindlela zokwelapha zofuzo, njengokuthi "ukulungisa" amaseli anomdlavuza naguqukile. Nokho, ososayensi bahlola izindlela ezingcono zokukhomba amangqamuzana ngokunembe ngokwengeziwe ngezinqubo zokuhlela zofuzo ezenzeka ngokwemvelo. Imithelela yesikhathi eside yokuhlelwa kwezakhi zofuzo okuhlelekayo ingase ihlanganise uxhaso olunyukile locwaningo lwezakhi zofuzo kanye namathuluzi angcono emithi yomuntu siqu.

Umongo wokuhlela ufuzo ohlelekayo

Ukuhlela i-genome kuyindlela enamandla evumela ososayensi ukuthi benze izinguquko eziqondiwe kukhodi yofuzo yento ephilayo. Le ndlela ingafinyelelwa ngezindlela eziningi ezahlukene, okuhlanganisa ukwethulwa kokunqamuka kwe-DNA noma ukuguqulwa kwezakhi zofuzo kusetshenziswa ama-nucleases akhethekile alandelanayo (SSNs).

Ngokwenza amakhefu anemicu ephindwe kabili (ama-DSB) ku-genome, ososayensi bangasebenzisa ama-SSN ahleliwe ukuze bakhombe amasayithi athile. Lawa ma-DSB abe eselungiswa izindlela ze-DNA zamaselula, njengokujoyina okungeyona i-homologous end join (NHEJ) kanye nokulungisa okuqondiswe ku-homology (HDR). Nakuba i-NHEJ ngokuvamile iphumela ekufakweni okungaqondakali noma ukususwa okungase kuphazamise ukusebenza kofuzo, i-HDR ingasethula izinguquko ezinembile futhi ishintshe ufuzo olungase lulungise.

Ithuluzi lokuhlela izakhi zofuzo ze-CRISPR lisetshenziswa kakhulu kulo mkhakha, elifaka umhlahlandlela (gRNA) kanye ne-enzyme ye-Cas9 "ukusika" izintambo eziyinkinga. Kunezinzuzo ezimbalwa ezingaba khona zokusebenzisa le ndlela, okuhlanganisa ukwelapha izifo ezinjengomdlavuza kanye ne-HIV (igciwane le-human immunodeficiency virus) kanye nokusungula izindlela zokwelapha ezintsha zezinye izifo. Kodwa-ke, izingozi nazo zihlotshaniswa, njengokuthi kungenzeka ukuthi ukuhlela okuthile kungase kwethule izinguquko eziyingozi ku-DNA yezinto eziphilayo. 

Ngo-2021, kwase kunezinkundla ze-software ezisekelwe kuwebhu ezingama-30 eziklanyelwe ukuhlela i-gRNA, ngokocwaningo olwanyatheliswa kujenali ye-Trends in Plant Science. Lezi zinhlelo zinamazinga ahlukene okuba yinkimbinkimbi, kanti ezinye zivumela ososayensi ukuthi balayishe inhlobonhlobo yokulandelana. Ukwengeza, amanye amathuluzi angakwazi ukunquma izinguquko ezingahlosiwe.

Umthelela ophazamisayo

Ngo-2021, ososayensi e-Massachusetts Institute of Technology (MIT) nase-Harvard University bathola ikilasi elisha lamasistimu okuguqula i-DNA ahlelekayo abizwa ngokuthi ama-OMEGAs (Obligate Mobile Element Guided Activity) engasebenzisi ubuchwepheshe be-CRISPR. Lezi zinhlelo zingase ngokwemvelo zishove izingcezu ezincane ze-DNA kuwo wonke ama-genome ebhaktheriya. Lokhu kutholwa kuvula indawo eyingqayizivele yebhayoloji engakhuphula ubuchwepheshe bokuhlela i-genome busuke engozini ebaliwe buyiswe enqubweni ebikezelwa kakhudlwana.

Lawa ma-enzyme mancane, okwenza kube lula ukuwaletha kumaseli kunama-enzyme amaningi, futhi angashintshwa ngokushesha ukuze asetshenziswe okuhlukile. Isibonelo, ama-enzyme e-CRISPR asebenzisa i-gRNA ukuze aqondise futhi acekele phansi abahlaseli begciwane. Kodwa-ke, ngokukhiqiza ngokulandelana kwazo i-gRNA, izazi zebhayoloji manje zingaqondisa umhlahlandlela we-enzyme ye-Cas9 kunoma iyiphi into ehlosiwe. Ukunethezeka la ma-enzyme angahlelwa ngakho kuwenza abe ithuluzi elinamandla lokushintsha i-DNA futhi kusikisela ukuthi abacwaningi bangawasebenzisa ekuthuthukiseni izindlela zokwelapha zokuhlela izakhi zofuzo. 

Esinye isiqondiso socwaningo esithembisayo ekuhleleni izakhi zofuzo ukuhlela okuphindwe kabili, ithuluzi elisekelwe ku-CRISPR elakhiwa ososayensi base-Harvard ngo-2022. Indlela entsha ivumela izingxenye ezinkulu ze-DNA ezinosayizi wofuzo ukuthi zisetshenziswe kumaseli omuntu ngaphandle kokusika i-DNA double helix. Ukwenza ukuhlela okukhulu kunalokho obekungenzeka ngaphambilini kungenza ososayensi bakwazi ukufunda nokwelapha izifo zofuzo ezibangelwa ukulahlekelwa umsebenzi wofuzo noma ukuguqulwa kwesakhiwo okuyinkimbinkimbi, okufana ne-hemophilia noma i-Hunter syndrome.

Imithelela yokuhlelwa kofuzo okuhlelekayo

Imithelela ebanzi yokuhlelwa kofuzo okuhlelekayo ingase ihlanganise: 

• Ukwenyuswa kwezimali ocwaningweni lokuhlela izakhi zofuzo okuhloswe ngazo ukuhlukanisa amasu asetshenziswa ukuthola izindlela zokunakekela ezinembe kakhudlwana neziphephe kakhudlwana.
• Ukuthuthukiswa kwemithi yomuntu siqu ngokusebenzisa izindlela zokwelapha ezihlosiwe zofuzo kanye nezifo.
• Amafemu e-Biotech athuthukisa isofthiwe engcono yokuhlela izakhi zofuzo ezishintshayo kanye nokunemba.
• Abanye ohulumeni bakhulisa uxhaso lwabo lwezimali kanye nokucwaninga ekuhleleni izakhi zofuzo ngokusebenzisa izivivinyo zokuhlola ezihlukahlukene ekwelapheni umdlavuza.
• Ubude bempilo ende yabantu abazalwa benezinguquko zofuzo.
• Amathuluzi amanoveli ofuzo aphinde ahloselwe ukubhekana nezifo eziyingozi nokuguqulwa kwezilwane nezinhlobo zezitshalo.

Imibuzo okufanele icatshangelwe

• Ucabanga ukuthi ukuhlelwa kofuzo okuhlelekayo kungayishintsha kanjani impilo?
• Yini ohulumeni abangayenza ukuze baqinisekise ukuthi lezi zindlela zokwelapha zifinyeleleka kuwo wonke umuntu?