Influences of somatic donor cell sex on in vitro and in vivo embryo development following somatic cell nuclear transfer in pigs

The present study investigates pre- and post-implantation developmental competence of nuclear-transferred porcine embryos derived from male and female fetal fibroblasts. Male and female fetal fibroblasts were transferred to -matured enucleated oocytes and and developmental competence of reconstructed embryos was investigated. And, a total of 6,789 female fibroblast nuclear-transferred embryos were surgically transferred into 41 surrogate gilts and 4,746 male fibroblast nuclear-transferred embryos were surgically transferred into 25 surrogate gilts. The competence to develop into blastocysts was not significantly different between the sexes. The mean cell number of female and male cloned blastocysts obtained by culture (143.8±10.5 to 159.2±14.8) was higher than that of culture of somatic cell nuclear transfer (SCNT) groups (31.4±8.3 to 33.4±11.1). After embryo transfer, 5 pregnant gilts from each treatment delivered 15 female and 22 male piglets. The average birth weight of the cloned piglets, gestation length, and the postnatal survival rates were not significantly different (p