Royana: Successful Experience in Cloning the Sheep

Objective: this study describes our experiences in reproductive cloning using two differentprocedures resulting in birth of the first successfully cloned sheep in iran and themiddle-east, nick-named royana.materials and methods: abattoir-derived sheep oocytes were enucleated after in vitromaturation for 18-20hrs and then reconstructed by ear-derived sheep somatic cells usingtwo different procedures of renucleation (subzonary, intracytoplasmic), embryo culture (coculture,sequential medium) and embryo transfer (intra fallopian, intra uterine). pregnancystatus and fetal development were followed regularly and elective cesarean was inductedon day 145 of pregnancy. histopathological and genetical examinations were performedon either aborted and delivered clones for confirmation different aspects of cloning.results: the two procedures were both efficient in producing early and/or advancedcloned embryos, establishing early and/or advanced stages of pregnancy till delivery. fourpregnancies were detected; one were failed at early pregnancy, one aborted on day 90,one was still born and the fourth delivered to a healthy male lamb nick named royana.conclusion: many different approaches have been developed for mammalian cloningwhich all are judged by their ultimate potency for establishment of successful pregnanciesterminated to healthy/viable clones. as a preliminary study toward establishment ofthe technology, this study also successfully examined the competency of two proceduresof somatic cell nuclear transfer (scnt). however, the overall low efficiency of scnt indicatesthat many different aspects of the technology remain to be dissolved.