Aggregation of Somatic Nuclear Transfer Embryos with In Vitro Fertilized Embryos at Two-cell Stage Increases the Efficiency of Blastocyst Rate in Goat

Background: Efficiency of somatic cell nuclear transfer (SCNT) has remained low due to a strong resistance of somatic donor cells to epigenetic reprogramming. Many approaches have been developed for improving in vitro and in vivo de-velopment of SCNT embryos. One of the promising methods for increasing SCNT efficiency is embryo aggregation. In the mouse, aggregation of two or three SCNT embryos leads to increased cell numbers, normalized Pou5f1 gene expression, and higher developmental rate. In bovine, the aggregation of parthenogenetic blastomeres with in vitro fertilization (IVF)-derived blastomeres increased survival rate after embryo trans-fer. In this study, we aimed at deciphering whether aggregation of SCNT derived goat embryos at 2-cell stage with 2-cell stage IVF embryos improves the efficiency of SCNT in terms of blas-tocyst rate.Materials and Methods: After producing SCNT embryos with handmade cloning (HMC) method and also IVF embryos with fertilization technique, IVF and SCNT 2-cell stage goat embry-os were aggregated by co-culturing them in aggregation plates. Six days after aggregation, the blastocyst rate were determined in IVF-SCNT aggregated and single SCNT embryos.Results: The percentage of blastocysts was higher (P<0.05) in IVF-SCNT aggregated embryos (27.72 ± 3.45 %) compared to that of single SCNT embryos (16.65 ± 4.58 %).Conclusion: Our results showed that aggregation of goat SCNT embryos at 2-cell stage with IVF embryos promotes the in vitro development in terms of blastocyst rate. However, more inves-tigations need to be performed in order to assess the expression of important developmentally genes in aggregated IVF-SCNT embryos in compare to single SCNT embryos.

Keywords:

SCNT , IVF , HMC , Blastocyst