Improving the genetic potential of farm animals is one of the primary aims in the field of assisted reproduction. In this regard, somatic cell nuclear transfer (SCNT) can be used to produce a large number of embryos from genetically elite animals. The aims of the present study were to assess the effects of: (1) ovary storage conditions on preimplantation development of recovered oocytes and the freezability of the derived blastocysts; and (2) vitrification of goat SCNT-derived blastocysts on postimplantation development. Goat oocytes were recovered from ovaries and stored under warm (25°C-27°C) or cold (11°C-12°C) conditions before being used to produce SCNT embryos. There were no differences in oocytes recovered from ovaries kept under cold versus warm storage conditions in terms of cleavage (mean (±s.d.) 95.68±1.67% vs 95.91±2.93% respectively) and blastocyst formation (10.69±1.17% vs 10.94±0.9% respectively) rates. The re-expansion rate of vitrified blastocysts was significantly lower for cold- than warm-stored ovaries (66.3±8.7% vs 90±11% respectively). To assess the effects of vitrification on postimplantation development, blastocysts from cold-stored ovaries only were transferred from fresh and vitrified–warmed groups. The pregnancy rate was comparable between the fresh and vitrified–warmed groups (41.65% and 45.45% respectively). In addition, established pregnancy in Day 28-38 and full-term pregnancy rates were similar between the two groups. In conclusion, this study shows similar invitro preimplantation developmental potential of warm- and cold-stored ovaries. This study introduces the vitrification technique as an appropriate approach to preserve embryos produced by SCNT for transfer to recipient goats at a suitable time.

Background: The ingredients of embryo culture media developed by different companies are disclosed. Thus, it is impossible to determine which ingredients might be responsible for differences in pre-and post-implantation embryo development. To address this gap, we performed an experiment to compare two embryo culture media, namely, SOF and commercial BO, on pre- and post-implantation development of cloned Sannen goat embryos. Cumulus oocyte complexes derived from slaughterhouse ovaries were used for in vitro embryo production . In vitro development of IVF, parthenogenetic and SCNT embryos were assessed in both BO and SOF media. The expression of 16 genes, including AKT , OCT4 , SOX2 , BMPR1 , FGFR4 , CDC25 , CDX2 , GCN5 , PCAF , FOXD3 , SMAD5 , FZD , LIFR1 , CTNNB , ERK1 , and IFNT , belonging to 7 important pathways, i.e. pluripotency, FGF, TGFβ, cell cycle and proliferation, histone transferase, trophectoderm, and WNT, were examined in the goat SCNT and IVF blastocysts from both BO and SOF media. Results: The blastocyst rate in BO medium was significantly higher than that of the SOF medium in SCNT embryos ( P < 0.05). All of the genes examined showed increased expression levels in SCNT embryos compared to IVF embryos. In the IVF group, OCT4 , BMPR1 , and GCN5 showed significantly higher expression in the SOF medium compared to the BO medium. In this group, AKT , FGFR4 , SOX2 showed significantly lower expression in the SOF medium compared to the BO medium. In the SCNT group, FGFR4 , GCN5 , FZD , CTNNB , BMPR1 , and FGFR4 showed significantly higher expression in SOF medium compared to BO medium. In vivo development did not differ significantly between the two groups. Conclusions: Based on these results, we concluded that the limited information available on the allocations of ICM and TE cells in SCNT embryos and embryo-specific gene expression may be the major drawback IVC medium and an impediment to successful animal cloning.