Abacwaningi bathole indima ebalulekile yokulungiswa kwe-DNA ngokushesha ekugcineni ukuqina kofuzo. Ucwaningo olusha lubonisa ukuthi ukulungiswa kwama-double-strand breaks (DSBs) ku-nuclear DNA kunikeza isivikelo esiphumelelayo ekuhlanganisweni kwe-DNA yangaphandle kusuka kuma-chloroplasts-into ethi, nakuba ibalulekile ekuziphendukeleni kwemvelo, ingaphazamisa kakhulu i-genome. Ucwaningo lwandisa ulwazi lwethu lokuvela kwezakhi zofuzo zezitshalo futhi lubalulekile kwezokwelapha.
Imiphumela, eyethulwe nguDkt. Enrique Gonzalez-Duran kanye noSolwazi uDkt. Ralph Bock be-Max Planck Institute of Molecular Plant Physiology in Nature Plants, ikhanyisa ukudluliswa kwezakhi zofuzo ze-endosymbiotic (EGT) – inqubo eqhubekayo yokuziphendukela kwemvelo lapho izakhi zofuzo ezivela kuma-organelles njenge-chloroplast kanye ne-mitochondria zidluliselwa ku-genome yenuzi. Nakuba ukudluliswa kwezakhi zofuzo okuphumelelayo kungathuthukisa ukubambisana phakathi kwe-nucleus kanye nama-organelles, inqubo nayo inezingozi ezinkulu: i-DNA efakiwe ingaphazamisa izakhi zofuzo ezibalulekile ku-nucleus futhi iholele ekuhleleni kabusha kwezakhi zofuzo okuyingozi.
Ithimba locwaningo lithole ukuthi indlela yokulungisa i-DSB idlala indima ebalulekile ekulawuleni imvamisa ye-EGT. Ukuze uqonde ukuthi izitshalo zilawula kanjani le nqubo, abacwaningi bagxile emigwaqweni yokulungisa i-DSB-izindawo zokungena ezaziwayo ze-organellar DNA. Besebenzisa izitshalo zikagwayi ezishintshwe izakhi kanye nohlelo lokuhlola olwakhiwe ngaphambilini lwemicimbi ye-EGT, bakhiphe ngokuqondile izindlela ezimbili ezihlukene zokulungisa i-DSB futhi bahlaziya izithombo ezingaphezu kuka-650.000 ngemicimbi emisha ye-EGT.
Imiphumela yayimangalisa: ukuvalwa kwendlela eyodwa yezindlela ezimbili zokulungisa kwaholela ekwenyukeni okukhulu kokudluliselwa kofuzo kusuka kuma-chloroplast kuya ku-nucleus - kwezinye izimo kuze kufike ku-20.
Ukuze bachaze abakubonile, abacwaningi bahlongoza imodeli entsha: Ngaphansi kwezimo ezijwayelekile, izitshalo zilungisa ngokushesha ama-DSB ku-DNA yazo yenuzi futhi zivale amasayithi asengozini ngaphambi kokuba i-organellar DNA ingene. Ngakho indlela yokulungisa isebenza njenge-molecular "umlindisango." Kodwa-ke, uma indlela eyodwa yokulungisa iphazamiseka, abanye banganxephezela kancane, kodwa inqubo iyonke ihamba kancane. Umphumela wesikhathi eside wokulungisa ushiya ama-DSB evuleka isikhathi eside - futhi kwandisa amathuba okuhlanganiswa kwe-chloroplast DNA. Umphumela uba ukwanda kwemicimbi ye-EGT, evame ukuhlotshaniswa nokuhlelwa kabusha kwe-genomic kanye nokwanda kokungazinzi. "Ubukhulu bomphumela bubonisa ukuthi ukulungiswa kwe-DNA okusheshayo kubalulekile ukuze izitshalo ziqinisekise ukuzinza kwesikhathi eside kwe-genome yazo," kuchaza uDkt. Enrique Gonzalez-Duran, umbhali oholayo wocwaningo.
Nakuba ukuhlola kwenziwa ezitshalweni zikagwayi, leli qembu likholelwa ukuthi indlela etholakele ingase idluliselwe kuwo wonke ama-eukaryote. "Lezi zindlela zokulungisa i-DNA zigcinwa ezilwaneni nasezikhunjini," kusho uProf. "Imiphumela yethu ingachaza izindlela ezifanayo zokungazinzi kwe-genome kwezinye izinto eziphilayo, kuhlanganise nabantu. Kudingeka izifundo ezengeziwe ukuze kucaciswe lokhu."
Ucwaningo luvula imibono emisha yokuthi i-organellar DNA inegalelo kanjani ekuthuthukisweni kokuguqulwa kwezakhi ku-nucleus yeseli. Kungase futhi kube nomthelela empilweni yomuntu-ikakhulukazi ngokuphathelene nebhayoloji yomdlavuza, lapho ukuhlanganiswa kwe-DNA ye-mitochondrial nokungaqini kwe-genomic kwaziwa njengezimbangela zamangqamuzana ze-tumorigenesis.
“Okutholakele kwethu kunikeza imininingwane eyisisekelo ngokuvikelwa kofuzo kanye nezingozi zokudluliswa kwezakhi zofuzo,” kunezela uGonzalez-Duran. "Kubonisa ukubaluleka kokulungiswa kwe-DNA ngokushesha-hhayi nje ukulungisa umonakalo, kodwa futhi nokuvikela ngenkuthalo ubuqotho be-genome."
Ukushicilelwa kwangempela
Enrique Gonzalez-Duran, Xenia Kroop, Anne Schadach, Ralph Bock
Ukucindezelwa kokudluliswa kofuzo lwe-plastid-to-nucleus nge-DNA yokulungisa ikhefu eliphindwe kabili
Izitshalo zemvelo (2025)
Funda futhi
Abacwaningi bathola izinhlanganisela ezintsha zokubambezela ukuqhakaza | I-Pugnalom
