Imfihlakalo Yokuzala Ixazululwe Ngokutholakala Kukhiye Wephrotheni
Ukungabi namandla okuzala kungabangelwa izici eziningi, kuhlanganise (kodwa kungagcini lapho) ukulimala kwe-DNA, ukuphazamiseka kwamakhromosomu, izimo zama-hormone, izinto ezihlobene nobudala, nezinto zemvelo. Ezinye izimo zokungabi namandla okuzala zithinta kuphela abesifazane, ezinye abesilisa, kanti ezinye zidalwa inhlanganisela yezimo kubalingani bobabili besilisa nowesifazane. Cishe izinyathelo ezingu-12 ziyabandakanyeka ekuphenyeni ngokujulile imbangela yokungabi namandla okuzala emibhangqwaneni. Ku ucwaningo olushicilelwe kuleli sonto kuNature, uDkt. Enrica Bianchi wase-Wellcome Trust Sanger Institute eCambridge, e-UK njengombhali ohola umsebenzi, ososayensi sebehambe isinyathelo eduze nokuxazulula imfihlakalo yokuzala ngokuthola iphrotheni ebalulekile ekusebenzelaneni kwesidoda neqanda.
Njengoba amandla okuzala eyisihloko esibaluleke kakhulu, kwenziwe ucwaningo oluningi ngawo. Ukhiye wokuqala kule mfihlakalo watholakala ngo-2005, lapho abacwaningi bethola iphrotheni ekhona ebusweni besidoda eyakwazi ukubona iqanda, ngaleyo ndlela ivumele ukuhlanganisana kwakho kwakhe i-embryo. Balinqamba igama elithi “Izumo,” elisho “itempeli lomshado” ngesiJapane. Ocwaningweni lwamanje, ithimba locwaningo libika ukutholwa kwephrotheni ehambisanayo ebusweni beqanda ebopha i-Izumo: baliqamba igama elithi Juno, egameni lenkosi yezithixo yokuzala yamaRoma. Lolu cwaningo luqinisekise nokuthi ukubophezela kwe-Izumo ku-Juno kuyisinyathelo sokuqala enhlanganisweni yesidoda neqanda, okungenzeki nhlobo ukuchanyuselwa ngaphandle kwalokhu. Lokhu kusebenzelana okukhethekile bekunzima ukukubamba, ngoba ukubophezela phakathi kwe-Izumo ne-Juno kubuthakathaka (okungukuthi ukubophezela kwazo kubuthuntu kakhulu). Ngemva kokuba iqanda lichanyuselwe, lisusa yonke i-Juno esele ebusweni balo kungakapheli imizuzu engama-40, ukuze livimbele ezinye izidoda ekubopheni: uma kungezwa isidoda esingaphezu kwesinye esihlanganiswa neqanda, i-zygote eyakhekayo ibiyoba namakhromosomu amaningi kakhulu, ngaleyo ndlela ingabi nethuba lokuphila.
Ukuze benze ukuhlola, ithimba locwaningo lathatha iphrotheni ye-Izumo esasivele yachazwa kahle, lakhulisa inguqulo yokwenziwa (artificial) yayo, ukuze libone ukuthi ibophezela kuphi eqandeni legundane. Basebenzisa indlela yokuhlola ebizwa nge-AVEXIS, eklanyelwe ukubona ukusebenzelana okubuthakathaka nokwedlula okwesikhashana phakathi kwamasamukeli (receptors) namaligand abophezela kuwo. Ngale ndlela bathola isamukeli sefolate esibizwa nge-Folr4, abesesilibiza kabusha ngokuthi Juno.
Ukuqinisekisa ukuthi i-Juno ibalulekile ekuzaleni kowesifazane, ithimba locwaningo ladala amagundane aguqulwe ngokwezakhi zofuzo (genetically modified) anganalo iphrotheni ye-Juno emaqandeni awo. Amaqanda ala magundane awazange ahlangane nezidoda, futhi amagundane ayengenamandla okuzala. Ukuqedela ukuqonda kwabo ukusebenzelana kwe-Izumo ne-Juno, abacwaningi baguqula ngokwezakhi zofuzo amagundane esilisa angenayo i-Izumo; la magundane abeseveza ukuthi awanakuzala.
Lolu cwaningo lubalulekile ngoba lunikeza indlela emfushane phakathi kwezinyathelo eziningi ezibandakanyeka ekwelapheni ukungabi namandla okuzala. Amaqanda nezidoda zemibhangqwana ebhekene nobunzima bokukhulelwa angahlolwa ngokwezakhi zofuzo ukuze kunqunywe ukuthi ama-protein abo e-Izumo ne-Juno akhiwe kahle yini. Uma kutholakala ukuthi la ma-protein anenkinga, imibhangqwana ingaqondiswa ngqo enhlanganisweni ebizwa nge-“ICSI” (intracytoplasmic sperm injection), lapho isidoda sitshalwa ngqo eqandeni, kusetshenziswa inaliti emincane kakhulu. UDkt. Gavin Wright, ohola i-Cell Surface Signalling Laboratory ye-Institute, unethemba lokuthi ukutholwa kwalokhu kusebenzelana okuyisiqongo kwephrotheni kuzoxazulula okungenani eyodwa yemfihlakalo yokuzala, futhi kuvumele ukuthuthukiswa kokwelashwa kokungabi namandla okuzala kanye nezindlela zokuvimbela ukukhulelwa.
