Effect of the Nuclear-Donor Cell Lineage, Type, and Cell Donor on Development of Somatic Cell Nuclear Transfer Embryos in Cattle

Abstract

Potential applications of somatic cell nuclear transfer to agriculture and medicine are currently constrained by low efficiency and high rates of embryonic, fetal, and neonatal loss. Nuclear transfer efficiency in cattle was compared between three donor-cell treatments from a single animal, between four donor-cell treatments in sequential stages of differentiation from a single cell lineage and genotype, and between the same cell type in two donors. Cumulus and granulosa donor cells resulted in a greater proportion of viable day-7 embryos than ear-skin cells; pregnancy rate and losses were not different among treatments. The least differentiated cell type in the follicular cell lineage, preantral follicle cells, resulted in fewer cloned blastocysts (11%) than cumulus (30%), granulosa (23%), and luteal (25%) donor cells. Cloned blastocysts that did develop from preantral follicle cells (75%) were more likely to progress through implantation into later stages of pregnancy than cloned blastocysts from cumulus (10%), granulosa (9%), and luteal (11%) donor cells (p < 0.05). Day-7 embryo development from granulosa cells was similar between two donors (19 vs. 24%) and proved to be a poor indicator of further development as day-30 pregnancy rates varied threefold between donors (48 vs. 15%, p < 0.05). Results reported here emphasize the crucial role of the nuclear donor cell in the outcome of the nuclear-transfer process.

Perinatal Physiology in Cloned And Normal Calves: Physical And Clinical Characteristics

“…Cloned calves from adult somatic cell nuclear transfer (Holstein, n ϭ 5; Hereford, n ϭ 3) and ET control calves (Holstein, n ϭ 3; Hereford, n ϭ 3) were produced as previously described, according to our established procedures (Batchelder et al, 2005). Briefly, nuclear-transfer experiments were conducted with donor cells from ear skin, cumulus, and granulosa cell lines from a 13-yearold Hereford donor and with donor cells from preantral follicle, cumulus, granulosa, and luteal cell lines from a 3-year-old Holstein donor.…”

The endometrium responds differently to cloned versus fertilized embryos

“…The high rate of pregnancy failure in recipients of cloned embryos has been linked to the finding of structural and functional abnormalities of the placenta. Losses of pregnancy in surrogate dams in the second and third trimester are associated with placental abnormalities, hydrops, enlarged umbilical cords with dilated vessels, and abnormally enlarged and fewer placental cotyledons (11)(12)(13). This abnormal placental development may be present from the early stages after implantation and can be overcome by some embryos that result in the development and birth of live clones (12,14,15).…”

Effect of Donor Cell Types on Developmental Potential of Cattle (Bos taurus) and Swamp Buffalo (Bubalus bubalis) Cloned Embryos

“…Yang et al [5] found that CCs and FFs have the same potential to support development of cloned rabbit embryos to the blastocyst stage. In contrast, many reports on cattle have suggested that CCs appear to be the best choice because of the highest cloning efficiency among the cells examined [12,15,18,25,[33][34][35]. Also, in buffalos, Shah et al [19] produced cloned embryos by a handmade cloning (HMC) technique and found that the blastocyst formation rate of embryos derived from CCs was better than those of embryos derived from FFs or adult fibroblasts.…”

“…Comparison of the reported cloning efficiency for each donor cell type is difficult due to variations in the nuclear-transfer procedures, source and quality of recipient oocytes, age and genotype of the donor cells and embryo culture systems used in the studies [18]. Furthermore, there have been few reports about the effect of donor cell types on the developmental potential of cloned buffalo embryos [4,19].…”