Ezinye izitshalo zingaphila izinyanga ngaphandle kwamanzi, bese ziphenduka zibe luhlaza futhi ngemva kwemvula encane. Ucwaningo lwakamuva olwenziwe yiNyuvesi yaseBonn naseMichigan lubonisa ukuthi lokhu akubangelwa “ufuzo oluyisimangaliso.” Kunalokho, leli khono liwumphumela wenethiwekhi yonke yezakhi zofuzo, cishe zonke ezikhona ezinhlobonhlobo ezisengozini kakhulu. Imiphumela isivele ivele ku-inthanethi ngo Ijenali Yezitshalo.
Esifundweni sabo, abacwaningi babheka ngokucophelela uhlobo oluye lwafundwa isikhathi eside eNyuvesi yaseBonn-isitshalo sokuvuka i-Craterostigma plantagineum. Ibizwa kahle ngegama layo: Ngezikhathi zesomiso, umuntu angase acabange ukuthi ifile. Kodwa ngisho nangemva kwezinyanga zesomiso, amanzi amancane anele ukuyivuselela. “Esikhungweni sethu, sekuyiminyaka eminingi sifunda ukuthi lesi sitshalo sikwenza kanjani lokhu,” kuchaza uProf. Dorothea Bartels we-Institute of Molecular Physiology and Biotechnology of Plants (IMBIO) eNyuvesi yaseBonn.
Izithakazelo zakhe zihlanganisa izakhi zofuzo ezibhekene nokubekezelela isomiso. Kwaba sobala ngokwengeziwe ukuthi leli khono aliwona umphumela “wofuzo oluyisimangaliso” olulodwa. Kunalokho, kuhileleke izakhi zofuzo eziningi, eziningi zazo ezitholakala nasezinhlotsheni zezilwane ezingamelani kahle nesomiso.
Lesi sitshalo sinamakhophi ayisishiyagalombili echromosome ngayinye
Ocwaningweni lwamanje, ithimba lika-Bartel, kanye nabacwaningi base-University of Michigan (US), bahlaziye i-genome ephelele ye-Craterostigma plantagineum. Futhi lokhu kwakhiwe ngendlela eyinkimbinkimbi: Nakuba izilwane eziningi zinamakhophi amabili e-chromosome ngayinye—elilodwa elivela kumama, elilodwa livela kubaba—i-Craterostigma inamakhophi ayisishiyagalombili. I-genome enjalo "ephindwe kasishiyagalombili" ibizwa nangokuthi i-octoploid. Thina bantu, ngokuphambene, siyi-diploid.
“Ukuphindaphindeka okunjalo kokwaziswa kofuzo kungabonwa kwabaningi izitshalo eziye zavela ngaphansi izimo ezimbi kakhulu,” kusho uBartels. Kodwa kungani kunjalo? Isizathu esingaba khona: Uma isakhi sofuzo sikhona kumakhophi ayisishiyagalombili esikhundleni samabili, ngokomgomo singafundwa ngokuphindwe kane ngokushesha. Ngakho-ke i-octoploid genome ingenza ukuthi inani elikhulu leprotheyini elidingekayo likhiqizwe ngokushesha okukhulu. Leli khono libonakala libalulekile ekuthuthukisweni kwe ukubekezelela isomiso.
E-Craterostigma, ezinye izakhi zofuzo ezihambisana nokubekezelela isomiso ziphinde ziphindaphindwe. Lokhu kufaka phakathi lokho okubizwa ngokuthi ama-ELIPs - isifinyezo sisho "amaprotheni aqala ukukhanya," njengoba eshintshwa ngokushesha ukukhanya futhi avikele ekucindezelekeni kwe-oxidative. Zitholakala ngamanani aphezulu kuzo zonke izinhlobo ezikwazi ukumelana nesomiso.
"I-Craterostigma inezakhi zofuzo ezicishe zibe ngu-200-ELIP ezicishe zifane futhi zitholakala kumaqoqo amakhulu amakhophi ayishumi noma angamashumi amabili kuma-chromosome ahlukene," kuchaza uBartels. Ngakho-ke izitshalo ezikwazi ukubekezelela isomiso zingasebenzisa uxhaxha olubanzi lwezakhi zofuzo ezingalulawula ngokushesha uma kunesomiso.
Izinhlobo ezingezwani nesomiso ngokuvamile zinezakhi zofuzo ezifanayo—nakuba ngamakhophi aphansi. Lokhu futhi akumangazi: Imbewu kanye nempova yezitshalo eziningi ngokuvamile zisakwazi ukumila ngemva kwesikhathi eside ngaphandle kwamanzi. Ngakho-ke nabo banohlelo lofuzo lokuvikela isomiso. “Kodwa-ke, lolu hlelo luvamise ukucishwa lapho luhluma futhi alukwazi ukuphinda lusebenze ngemva kwalokho,” kuchaza isazi sezitshalo. "Ezitshalweni zokuvuka, ngokuphambene, ihlala isebenza."
Izinhlobo eziningi 'zingenza' ukubekezelela isomiso
Ngakho-ke, ukubekezelela isomiso kuyinto “izitshalo eziningi ezingayenza”. Izakhi zofuzo ezinikeza leli khono cishe zavela ekuqaleni kwenkathi yokuziphendukela kwemvelo. Nokho, lawa manethiwekhi asebenza kahle kakhulu ezinhlotsheni ezimelana nesomiso futhi, ngaphezu kwalokho, awasebenzi kuphela ezigabeni ezithile zomjikelezo wokuphila.
Sekushiwo lokho, akuwona wonke amaseli e-Craterostigma plantagineum “anohlelo lwesomiso” olufanayo futhi. Lokhu kuboniswe ngabacwaningi baseNyuvesi yaseDüsseldorf, nabo ababambe iqhaza kulolu cwaningo. Isibonelo, izakhi zofuzo zenethiwekhi yesomiso ezihlukene zisebenza ezimpandeni ngesikhathi sokuhluma kunamahlamvu. Lokhu okutholakele akukona okungalindelekile: Amaqabunga, isibonelo, adinga ukuzivikela emiphumeleni elimazayo yelanga. Basizwa kulokhu ngama-ELIP, isibonelo. Ngomswakama owanele, lesi sitshalo sakha izingulube ze-photosynthetic ezimunca imisebe okungenani kancane. Lesi sivikelo semvelo siyehluleka kakhulu ngesikhathi sesomiso. Izimpande, ngokuphambene, akudingeki zikhathazeke ngokushiswa yilanga.
Ucwaningo luthuthukisa ukuqonda ukuthi kungani abanye zinhlobo bahlupheke kancane ngenxa yesomiso. Ngokuhamba kwesikhathi, kungaba nomthelela ekuzalweni kwezitshalo ezinjengokolweni noma ummbila okwazi ukubhekana kangcono nazo. isomiso. Ezikhathini zokuguquguquka kwesimo sezulu, lezi ngokunokwenzeka zizodingeka kakhulu kunangaphambili esikhathini esizayo.