Ngenkathi uXiaoxi Meng noZhikai Liang behlongoza lo mbono okokuqala eminyakeni embalwa edlule, uJames Schnable wayenokungabaza. Ukusho okuncane.
“'Hhayi-ke, ungazama, kodwa angicabangi ukuthi kuzosebenza,'” uprofesa osebenzisana naye we-agronomy ne-horticulture ukhumbule esho ku-Meng no-Liang, ngaleso sikhathi ababengabacwaningi be-postdoctoral elebhu ka-Schnable e-University of Nebraska-Lincoln.
Wayenephutha futhi, ngokubheka emuva, akazange ajabule kakhulu ukuba abe. Nokho ngaleso sikhathi, uSchnable wayenesizathu esizwakalayo sokuphakamisa ishiya. Umbono walaba ababili - wokuthi ukulandelana kwe-DNA yezitshalo ezizwelayo ukubanda ezivumela isithwathwa esiqinile kungasiza ukubikezela ukuthi izitshalo zasendle eziqinile, ezikwazi ukubekezelela izimo ezibandayo - wabonakala unesibindi. Ukusho okuncane. Noma kunjalo, kwakuyisiphakamiso esinengozi ephansi, enomvuzo omkhulu. Ngoba uma uMeng no-Liang bengayenza isebenze, ingase isheshise imizamo yokwenza izitshalo ezingazweli ukubanda kancane noma zifane kakhulu nozakwabo abamelana nokubanda.
Ezinye zezitshalo ezibaluleke kakhulu emhlabeni zafuywa ezindaweni ezishisayo - ummbila eningizimu yeMexico, amabele empumalanga ye-Afrika - okungafaki ingcindezi ekhethiwe kuzo ukuthi iguqule ukuzivikela emakhazeni noma emakhazeni. Uma lezo zitshalo zitshalwa esimweni sezulu esinzima, ukuzwela kwazo emakhazeni kunciphisa ukuthi zingatshalwa kusenesikhathi kangakanani nokuthi zingavunwa sekwephuzile kangakanani. Izinkathi zokukhula ezimfishane zilingana nesikhathi esincane se-photosynthesis, okuholela ekuvuneni okuncane nokudla okuncane kwenani labantu emhlabeni wonke okulindeleke ukuthi lisondele kubantu abayizigidi eziyizinkulungwane eziyi-10 ngo-2050.
Isimo sezulu esibandayo
Izinhlobo zezitshalo ezivele zikhule ezindaweni ezibandayo, okwamanje, zavela amaqhinga okubekezelela amakhaza. Bangakwazi ukuhlela kabusha ulwelwesi lwamaselula ukuze balondoloze amanzi emazingeni okushisa aphansi, bavimbele ulwelwesi ekubandeni nasekuqhekekeni. Bangakwazi ukwengeza amadeshi kashukela oketshezini olungaphakathi naseduze kwalolo lwelwesi, behlise izinga lokuqhwalela ngendlela efanayo nosawoti owenza ngayo umgwaqo oseceleni. Angakwazi ngisho nokukhiqiza amaprotheni ancibilikisa amakristalu eqhwa amancane ngaphambi kokuba lawo makristalu akhule abe uquqaba oluqhuma amangqamuzana.
Zonke lezo zivikelo zisuka ezingeni lofuzo, nakuba hhayi nje ngokulandelana kwe-DNA ngokwayo. Lapho izitshalo ziqala ukuba yiqhwa, zingaphendula ngokuvala noma zivule izakhi zofuzo ezithile - zivimbele noma zivumele iziqondiso zazo zofuzo ukuthi zilotshwe futhi zenziwe. Khona-ke, ukwazi ukuthi yiziphi izakhi zofuzo ezikwazi ukumelana nokubanda ezicimayo futhi ziqhubeke lapho zibhekene namakhaza, kungasiza abacwaningi baqonde izisekelo zezinqaba zabo, futhi ekugcineni, bathuthukise indlela yokuzivikela efanayo ibe izitshalo ezingezwani nokubanda.
Kodwa u-Schnable wayazi, njengoba uMeng no-Liang benza, ukuthi ngisho nofuzo olufanayo luvame ukuphendula ngendlela ehlukile emakhazeni kuzo zonke izinhlobo zezitshalo, ngisho nalezo ezihlobene eduze. Okusho ukuthi, ngokukhungathekisayo, ukuthi ukuqonda indlela isakhi sofuzo esisabela ngayo emakhazeni ohlotsheni oluthile kuvame ukutshela ososayensi bezitshalo cishe akukho okuqinisekile mayelana nokuziphatha kwesakhi kolunye. Lokho kungaqiniseki, kuye kwaphazamisa imizamo yokufunda imithetho ebeka ukuthi yini ezovala noma yenze izakhi zofuzo zisebenze.
"Sisekubi ngempela ekuqondeni ukuthi kungani ufuzo luvala futhi luqhubeke," kusho uSchnable.
Izitshalo zommbila
Njengoba bengenayo incwadi yomthetho, abacwaningi baphendukela ekufundeni ngomshini, uhlobo lobuhlakani bokwenziwa olungabhala olwalo. Bakhe ngokukhethekile imodeli yokuhlukanisa egadiwe - uhlobo olungakwazi, uma lwethulwa ngezithombe ezinelebula ezanele, okuthi, amakati kanye nokungewona amakati, ekugcineni lufunde ukuhlukanisa okokuqala kwakamuva. Ithimba laqale lethule imodeli yalo ngenqwaba yezakhi zofuzo ezilandelanayo ezivela kummbila, kanye nesilinganiso samazinga okusebenza alezo zakhi zofuzo lapho isitshalo sibhekene nezinga lokushisa elibandayo. Imodeli iphinde yaphakelwa “zonke izici esingacabanga ngazo” zofuzo lommbila ngamunye, kusho uSchnable, okuhlanganisa ubude bawo, ukuzinza kwawo nanoma yimuphi umehluko phakathi kwawo nezinye izinhlobo zawo ezitholakala kwezinye izitshalo zombila.
Kamuva, abacwaningi bahlola imodeli yabo ngokuyifihlela ucezu olulodwa nje lolwazi kusethi yalezo zakhi zofuzo: noma ngabe basabela ekuqaleni kwamazinga okushisa aqandayo, noma abasabelanga. Ngokuhlaziya izici zezakhi zofuzo ezazitshelwe ukuthi ziyasabela noma aziphenduli, imodeli yabona ukuthi yiziphi izinhlanganisela zalezo zici ezihambisana nenye ngayinye - yase ifaka ngempumelelo iningi lezakhi zofuzo ezisele, eziyimfihlakalo ezigabeni zazo ezifanele.
Kwakuyisiqalo esithembisayo, ngokungangabazeki. Kodwa ukuhlolwa kwangempela kwasala: Ingabe imodeli yayingathatha ukuqeqeshwa eyayikutholile ohlotsheni oluthile futhi ikusebenzise kolunye?
Impendulo yaba nguyebo oqinisekile. Ngemva kokuqeqeshwa ngedatha ye-DNA yohlobo olulodwa lwezinhlobo eziyisithupha - ummbila, amabele, i-pearl millet, i-proso millet, i-foxtail millet noma i-switchgrass - imodeli ngokuvamile yakwazi ukubikezela ukuthi yiziphi izakhi zofuzo kunoma yiziphi ezinhlanu ezingaphendula ekuqandeni. Okwamangaza u-Schnable, imodeli yabambelela ngisho nalapho iqeqeshwa ohlotsheni olungezwani nokubanda - ummbila, amabele, iparele noma i-proso millet - kodwa inikezwe umsebenzi wokubikezela izimpendulo zofuzo kunyaluthi we-foxtail okwazi ukumelana nokubanda noma utshani obushintshashintshayo.
imodeli
"Amamodeli esiwaqeqeshe asebenza cishe kuzo zonke izinhlobo zezilwane njengokungathi unedatha ohlotsheni olulodwa futhi wasebenzisa idatha yangaphakathi ukwenza izibikezelo ngalolo hlobo lwezinhlobo ezifanayo," esho, okumangazayo ezwini lakhe ezinyangeni kamuva. "Ngempela bengingeke ngikubikezele lokho."
"Umbono wokuthi singakwazi ukufaka lonke lolu lwazi kukhompyutha, futhi ingathola okungenani imithetho ethile ukuze ibikezele ukuthi izosebenza, usangimangalisa."
Lezo zibikezelo zingaba usizo ikakhulukazi lapho ucabangela enye indlela. Cishe iminyaka eyishumi, izazi zezinto eziphilayo zezitshalo empeleni ziye zakwazi ukukala inani lama-molecule e-RNA - lawo anesibopho sokuloba nokuthutha imiyalelo ye-DNA - akhiqizwa yilo lonke ufuzo esitshalweni esiphilayo. Kodwa ukuqhathanisa indlela lelo gama lofuzo elisabela ngayo emakhazeni ezinhlobonhlobo eziphilayo, nasezinhlotsheni eziningi zezilwane, kuwumsebenzi onzima, kusho uSchnable. Lokho kuyiqiniso ikakhulukazi ngezitshalo zasendle, okungaba nzima ngisho ukuzitholela imbewu yazo. Lezo zimbewu zingase zingaqhumi lapho zilindelwe, uma zinjalo, futhi zingase zithathe iminyaka ukukhula. Noma kunjalo, zonke izitshalo eziphumayo kufanele zilinywe endaweni efanayo, elawulwayo futhi zifundwe esigabeni sokukhula esifanayo.
Izinhlobo ezengeziwe
Konke lokho kudala inselele enkulu ekukhuliseni izibonelo zasendle ezanele, ezisuka ezilwaneni zasendle ezanele, ukuze ziphindaphindeke futhi zihlole ngokwezibalo ukusabela kwezakhi zazo zofuzo emakhazeni.
"Uma sifuna ngempela ukuthola ukuthi yiziphi izakhi zofuzo ezibalulekile - empeleni ezidlala indima endleleni isitshalo esivumelana ngayo nokubanda - kudingeka sibheke izinhlobo ezingaphezu kwezimbili," kusho uSchnable. “Sifuna ukubheka iqoqo lezinhlobo ezikwaziyo ukumelana nokubanda kanye neqembu elizwelayo, futhi sibheke amaphethini: “Lolufuzo luhlala luphendula kwesinye futhi aluphenduli kwesinye.”
“Lokho kuqala ukuba ukuhlolwa okukhulu futhi okumba eqolo. Kungaba kuhle ngempela uma singenza izibikezelo ezilandelanayo ze-DNA yalezo zinhlobo zezilwane esikhundleni sokuthi, sithi, sithathe izinhlobo ezingama-20 futhi sizame ukuzithola zonke esigabeni esifanayo, sizibeke kuzo zonke izindlela zokwelapha zokucindezeleka ezifanayo, futhi ukukala inani le-RNA elikhiqizwa isakhi sofuzo ngasinye ohlotsheni ngalunye.”
Ngenhlanhla yemodeli, abacwaningi sebevele balandelanisa ama-genome ezinhlobo zezitshalo ezingaphezu kuka-300. Umzamo oqhubekayo wamazwe ngamazwe ungenza lelo nani lifinyelele ku-10,000 eminyakeni embalwa ezayo.
Yize imodeli isivele yeqe kakhulu abekulindele, uSchnable uthe isinyathelo esilandelayo sizobandakanya "ukuzikholisa thina nabanye abantu" ukuthi isebenza kahle njengoba senzile kuze kube manje. Kuzo zonke izimo zokuhlola kuze kube manje, abacwaningi bacele imodeli ukuthi ibatshele lokho asebekwazi kakade. Uthe uvivinyo olukhulu luzofika lapho abantu nomshini sebeqala phansi.
“Ukuhlola okukhulu okulandelayo engicabanga ukuthi kudingeka sikwenze ukubikezela uhlobo oluthile lapho singenayo khona idatha nhlobo,” esho. "Ukuqinisekisa abantu ukuthi kusebenza ngempela ezimeni lapho nathi singazazi izimpendulo."
Ithimba labika lokho elikutholile encwadini ethi Proceedings of the National Academy of Sciences. UMeng, uLiang kanye noSchnable bagunyaze lolu cwaningo noRebecca Roston waseNebraska, uYang Zhang, uSamira Mahboub kanye nongumfundi owenza iziqu uDaniel Ngu, kanye no-Xiuru Dai, isazi esivakashile saseShandong Agricultural University.
Ukuze uthole ukwaziswa okwengeziwe:
Inyuvesi yaseNebraska Lincoln
www.unl.edu