Hanze y’U Rwanda

CRISPR-Cas9, uburyo bufasha guhindura ADN/DNA bukora gute ?

CRISPR-Cas9, uburyo bufasha guhindura ADN/DNA  bukora gute ?

Uko iminsi ihita niko ikoranabuhanga rigenda ritera imbere cyane. Mu buvuzi naho ntibasigaye inyuma. Guhindura imiterere ya ADN y’umwana uri mu nda, hagakurwaho indwara z’uruhererekane zo mu miryango (maladies héréditaires) ni kimwe mu bikorwa bizafasha ubuvuzi gutera imbere no kuvura indwara zikomeye.

ADN/DNA mu magambo arambuye ni Acide désoxyribonucléique/deoxyribonucleic acid. Tugenekereje mu Kinyarwanda twayisobanura nk’ utunyangingo tw’ibanze tugena imiterere y’umuntu. Utu tunyangingo nitwo zingiro ry’aya masura dufite, ni two dutuma buri gice cy’umubiri kiri aho kiri.

Muri 2013 nibwo bwa mbere hatangiye kugeragezwa uburyo bufasha kuba hahindurwa imiterere ya ADN ya buri kinyabuzima cyose kibaho ndetse n’ibihingwa hifashishijwe uburyo bwiswe CRISPR-Cas9. Ubu buryo bwagizwe ubuvumbuzi bwa mbere mu mwaka wa 2015 na Magazine yitwa Science yo muri Amerika. Impamvu bwabonye uyu mwanya, ni uko ubu buryo ngo buzafasha guteza imbere ubuvuzi kuburyo bugaragara.

Ni uburyo bwavumbuwe n’abagore 2: Jennifer Doudna wo muri kaminuza ya Berkeley afatanyije na Emmanuelle Charpentier wo muri Institut Max-Planck y’i Berlin. Babutangajeku nshuro ya mbere muri 2012. Ubuvumbuzi bwabo babuherewe igihembo L’Oréal-Unesco 2016.

Cas9 ni ubwoko bwa ‘Enzyme’ iba ikoze nk’umukasi, ishobora kubasha kumenya igice runaka cya ADN ndetse ikabasha no kucyangiza, igikasemo ibice 2 biba bigize ADN (détecter une partie spécifique de l’ADN et la détruire, coupant ainsi la double hélice/can find, cut out and replace specific parts of DNA).

Kugira ngo iyi ‘Enzyme’ imenye igice igomba gucamo kabiri, iyoborwa n’igice cya ARN (acide ribonucléique) bita ARN guide/guide RNA (gRNA). ‘ARN guide’ igaragaza igice kigomba gukurwaho , ndetse n’igice cya ADN kijyanye n’igishya kigomba gushyirwaho(servant de guide pour repérer le gène à enlever et un segment d’ADN correspondant au nouveau gène à insérer).

Mu gukora kwayo, CRISPR-Cas9 ishobora gutuma ‘gène’(agace gato ko kuri ADN) ihagarara gukora cyangwa se ikaba yafasha kwinjiza ADN nshya mu mubiri iturutse hanze yawo. Kuberako ubu buryo bukora nk’umukasi, ahenshi uzasanga babwita cisseaux genetique/ Genetic Scissors

Mu kuvumbura ubu buryo, kimwe mu byari bigamijwe ni ukurinda no gukiza ikiremwamuntu indwara zikomoka ku ruherekane rw’imiryango (maladies génétiques )nk’uko byasobanuwe na Emmanuelle Charpentier. Hakoreshejwe ubu buryo, umwana ukiri mu nda ugaragaza ko yazavukana uburwayi runaka bw’akarande , abaganga bazajya bashobora kumuhindurira imiterere ya ADN, hagasimbuzwa igice kiriho uburwayi, hakongerwamo ikindi.

Mu nkuru yayo ‘Sciences : CRISPR-CAS9, une révolution biologique qui divise’, France TV yo itangaza ko ubu buryo bufungura inzira yo kuba havurwa uburwayi bwa Kanseri, Sida ndetse n’indwara yo kwibagirwa( Alzheimer). Muri make iki kinyamakuru gihamya ko ubu buryo buzafasha ikiremwamuntu kubasha guhangana n’indwara ndetse icyizere cyo kubaho kikiyongera(espérance de vie).

Mu ntangiriro z’umwaka wa 2014 nibwo ikinyamakuru Cell cyatangaje ivuka ry’inguge 2 za mbere zavutse habanje guhindurwa imiterere y’utunyangingo hifashishijwe Cripsr-Cas9. Izi nguge zahawe amazina ya Lingling na Mingming zavukiye mu Bushinwa. Xingxu Huang wo muri Kaminuza ya Nankin na bagenzi be nibo babashije gukora iki gikorwa.

Nyuma y’imyaka 2 zivutse, Lingling na Mingming zimeze neza nk’uko byemezwa na Weizhi Ji wahoze ayobora inzu ibamo inyamanswa(zoo ) ya Kunming akaba n’umwe mu bagize ‘Académie des sciences’ y’Ubushinwa.

" Turakomeza kuzikurikiranira hafi kugira ngo turebe niba Cripsr nta ngaruka mbi ifite zo mu gihe kirekire. Ubushakashatsi turacyabukomeje. Hari ibindi byisumbuyeho twagezeho ariko nta byinshi nabivugaho kugeza ubu. " Aya ni amagambo Weizhi Ji yatangarije ikinyamakuru Le monde.Ni amagambo ushobora gusanga mu nkuru y’iki kinyamakuru ’ Jusqu’où manipuler le vivant ?’ yo ku wa 15 Kanama 2016.

Lingling na Mingming zavutse hakoreshejwe uburyo bwa Cripsr-Cas9

Mu kwezi kwa Kanama 2016, mu Bushinwa hakoreshejwe ubu buryo mu kugerageza kuvura abarwayi bakuru barwaye kanseri y’ibihaha nk’uko byatangajwe n’ikinyamakuru Nature mu nkuru cyahaye umutwe ugira uti ‘Chinese scientists to pioneer first human CRISPR trial’. Yari inshuro ya mbere ubu buryo bugeragerejwe ku kiremwamuntu. Ni igikorwa cyayobowe na Lu You, inzobere yigisha muri Sichuan University , kaminuza y’ivuriro rya Chengdu , mu Burengerazuba bw’Ubushinwa.

" Ubu buryo ni akataraboneka kandi abarwayi bazabwungukiramo cyane cyane abarwayi ba kanseri twitaho umunsi ku wundi . Ndakeka ko turi abambere mu kugeragereza ubu buryo ku barwayi, kandi mfite icyizere ko tuzabona ibisubizo byiza tuzakura mu igererageza." Aya ni amagambo Lu yatangarije ikinyamakuru Nature.

CNN yatangaje ko kugira ngo abaganga byo muri ibi bitaro babashe gukoresha ubu buryo bwo kuvura kanseri bifashishije uburyo bwa CRISPR-Cas9, bagombaga kubanza kumenya neza niba ubu buryo koko bwizewe. Icyiciro cya mbere cyari icyo kubanza gusuzuma abantu 10, hakarebwa uko imibiri yabo ikora, niba ntaningaruka byabagizeho.

Muri Gicurasi 2017, ikinyamakuru Nature Methods cyari cyanditse inkuru ivuga ko ubu buryo bushobora guteza ibibazo nyuma y’aho bagaragazaga ko CRISPR-Cas9 yateje impinduka zitari ngombwa muri ADN y’imbeba zari zakoreweho ubushakashatsi (CRISPR-Cas9 causait des changements inattendus dans l’ADN de souris).

Nyuma yaho abashakashatsi banyuranye banenze ibyagendeweho mu nyigo yatumye Nature Methods ivuga ko CRISPR-Cas9 ishobora guteza ibibazo. Nyuma yaho abo bashakashatsi banditse inkuru inyuzwa mu kinyamakuru BioRχiv bagaragaza uburyo ibyanezwe CRISPR-Cas9 bitakorewe inyigo ihamye.

Nyuma yaho Nature Methods yakuyeho inkuru yagaragazaga ko CRISPR-Cas9 yateze ibibazo ndetse muri Werurwe 2018, Nature Methods isaba imbabazi inavuga ko yagombaga kubanza gushaka inzobere muri ’Genetique’ mbere yo gutangaza inkuru yabo.

Mu mafoto y’urukurikirane , urabona uko iki gikorwa kigenda. ku ifoto ya mbere urabona agace kagomba gukurwaho(target sequence). Ku ifoto ya 2 miya 3, guide ARN igiye kwereka ’Enzyme’ ya Cas 9, agace ka nyako kagomba gukurwaho. Ku ifoto ya 4, Cas 9 ikuyeho igice cyagombaga kuvaho, naho ku ifoto iheruka urabona aho agace kakuweho hasubiranwa(mutation)

Emmanuelle Charpentier ( i bumoso) na Jennifer Doudna bafatanyije mu kuvumbura uburyo bwa Cripsr-Cas9

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