Ukuthuthukisa izingane: Ingabe izingane ezisanda kuzalwa ezithuthukisiwe ziyamukeleka?

• About the Author:
• Igama lomlobi

  I-Quantumrun Foresight
• November 2, 2022

Isifinyezo sokuqonda

Umqondo wezingane zomklami uzohlala uthakazelisayo futhi uphikisana. Amathuba okuthi izakhi zofuzo "zingalungiswa" noma "zihlelwe" ukuze kwakheke abantu abaphile kahle abangenazo izingozi zokuthola izifo zofuzo njengefa kubonakala kuyinto engcono kakhulu engatholwa isintu. Nokho, njengakho konke ukuhlola kwesayensi, kunemigqa yokuziphatha ososayensi abesabayo ukuwela.

Ukuthuthukisa umongo wezingane

Ukuhlela i-genome kuthole ukunakwa okubalulekile ngenxa yamandla ako okulungisa izakhi zofuzo ezinesici, kanye namandla ako okukhiqiza izinguquko zofuzo ezingahlosiwe (ukuhlelwa ngaphandle kokuhlosiwe). Indlela esabalele kakhulu yokuguqula izakhi zofuzo isebenzisa i-CRISPR–Cas9, indlela egqugquzelwe indlela yokulwa negciwane esetshenziswa amanye amagciwane.

Ithuluzi lokuhlela isakhi sofuzo lenza ukusikeka ku-DNA kusetshenziswa i-enzyme ye-Cas9. Usosayensi angase anikeze i-Cas9 ucezu lwe-RNA ukuze iyiqondise endaweni ethile ku-genome. Kodwa-ke, njengamanye ama-enzyme, i-Cas9 yaziwa ngokusika i-DNA kwezinye iziza ngaphandle kokuhlosiwe lapho kunokulandelana kwe-DNA okufanayo ku-genome. Ukusikeka 'okungaqondiwe' kungase kubangele izinkinga ezihlukahlukene zezempilo, njengokususwa kofuzo okuholela kumdlavuza. 

Ngo-2015, abacwaningi benza ucwaningo lokuqala lwe-CRISPR emibungu yabantu. Kodwa-ke, izifundo ezinjalo azikajwayelekile futhi zivame ukulawulwa kakhulu. Ngokusho kwesazi sesayensi yokuzala uMary Herbert eNyuvesi yaseNewcastle e-UK, okutholakele kugqamisa okuncane mayelana nendlela imibungu yabantu eyilungisa ngayo i-DNA eyonakaliswe ubuchwepheshe bokuhlela i-genome. Ocwaningweni, imibungu yasetshenziswa ngenxa yezizathu zemfundo kuphela hhayi ukudala izingane. Futhi kusukela ngo-2023, ukuhlela kwe-germline, noma ukulungisa amaseli okuzala, kuvinjelwe emazweni amaningi.

Umthelela ophazamisayo

Abanye ososayensi baphikisa ngokuthi noma ngabe izinguquko ku-genome yomuntu beziqondiswe ngokuphelele futhi zinembe, kusadingeka bacabangele ukuthi yikuphi ukuhlela okuphephile. Ngo-2017, ukusebenzisana kwamazwe ngamazwe okuholwa yi-US National Academies of Sciences, Engineering, and Medicine kwakhipha imihlahlandlela yokuhlela imibungu yabantu ezofakwa. 

Esinye isimo sasiwukuthi ukulandelana kwe-DNA ehleliwe kumelwe kakade kugcwele kubantu abaningi futhi kungabi yingozi yezempilo eyaziwayo. Lo mthetho uvimbela ukuhlelwa kwezakhi zofuzo ngenxa yokuthi le ndlela idinga ukukwazi ukubikezela ukulandelana okunembile kokuhlela, okuyinselele. 

Ezinye izindaba zokuziphatha zihlupha umqondo wokukhulisa izingane. Abanye abenzi benqubomgomo bakhathazekile ngokuthi ukuthola imvume yokwaziswa yokwelashwa kwegciwane kunzima ngoba iziguli ezizozuza ekulungisweni ziwumbungu nezizukulwane ezizayo. Impikiswano ephikisayo ibeka ukuthi abazali njalo benza izinqumo ezibalulekile egameni lezingane zabo, ngokuvamile ngaphandle kwemvume yabo; isibonelo esisodwa i-PGD/IVF (Preimplantation Genetic Diagnosis/In-vitro Fertilization) ehlanganisa ukuhlola imibungu engcono kakhulu yokufakelwa. 

Abacwaningi kanye nezazi ze-bioethicists baphinde bakhathazeke ngokuthi abazali abazoba abazali bangakwazi yini ukunikeza imvume enolwazi lwangempela kuyilapho imiphumela engemihle yokwelashwa kwe-germline ingaziwa. Kuphinde kube nodaba lwalokhu kuhlelwa kofuzo okuthuthukisa ezinye izikhala zenhlalo-mnotho ekufinyeleleni ekunakekelweni kwezempilo. Abanye bakhathazekile ngokuthi ubunjiniyela be-germline bungase buphumele emaqenjini ahlukene abantu abachazwe ikhwalithi yabo ye-DNA eshintshwe izakhi.

Imithelela yokuthuthukisa izingane

Imithelela ebanzi yokuthuthukiswa kwezingane ingase ihlanganise: 

• Ukuthuthukiswa okuqhubekayo kwamathuluzi okuhlela ufuzo akhela phezu noma anembe kakhulu kune-CRISPR.
• Amafemu e-Biotech azama ubuchwepheshe bokuqagela okusekelwe kufuzo olunembile esebenzisa ama-algorithms. Lo mkhuba uzosiza abangaba abazali bahlole imibungu.
• Ukwamukelwa okungenzeka kwezingane eziguquliwe, ikakhulukazi lezo ezingase zizuze izifo ezisongela ukuphila. Nokho, lokhu kukhula kungase kuqhubeke kancane kancane kwehle endaweni eshelelayo ephumela ekubeni abazali “baklame” izingane zabo zesikhathi esizayo. 
• Izingane ezizalwa zikhubazekile njengokungaboni kahle nokungezwa seziyinto yesikhathi esidlule.
• Ukwenyuswa kwezimali ekuhlolweni kokuhlela ufuzo lwe-embryo CRISPR, nakuba abanye ososayensi bangase bafune ukuthi ohulumeni babeke obala kulezi zinhlobo zocwaningo.
• Umphakathi wesayensi uhlukanise phakathi kweqembu elimela ucwaningo lokuhlela i-germline eligadiwe kanye nelinye elifuna luvinjelwe unomphela.

Imibuzo okufanele icatshangelwe

• Ucabanga ukuthi kuzokwenzekani lapho abazali bezuza ikhono nelungelo lokusebenzisa “ngokuphephile” izakhi zofuzo zezingane zabo?
• Ingabe lokhu kusungula kungalawulwa emhlabeni wonke noma ingabe umncintiswano kazwelonke wokuzalwa kwabantu abanempilo enhle noma othuthukisiwe uzokwenza lobu buchwepheshe bungenakugwenywa?