Effects of Embryo Aggregation and PXD101 on the In Vitro Development of Mouse Somatic Cell Nuclear Transfer Embryos

To improve the cloning efficiency of somatic cell nuclear transfer (SCNT) and to establish nuclear transfer embryonic stem cells (NT-ESCs) reliably, it is necessary to produce high-quality blastocysts derived from mice SCNT embryos. Therefore, the present study aims to investigate an optimal method for mouse SCNT embryo production and NT-ESCs derivation by comparing the effects of two methods: the treatment of histone deacetylase inhibitor PXD101 after SCNT, embryo aggregation and their combination treatment. The results suggest that embryo aggregation at four-cell stage and 50 nM PXD101 treated for 10 hours during and after activation could improve both mouse SCNT embryos' development (PXD101: 40.0% vs. 18.5%; p < 0.05; aggregation: 40.2% vs. 18.5%; p < 0.05) and also enhance the isolation rate of NT-ESCs (PXD101: 38.2% vs. 12.5%; p < 0.05; aggregation: 39.0% vs. 12.5%; p < 0.05). The combination of their treatments had a higher development rate (43.6%) and significantly higher NT-ESCs isolation rate (54.7%), therefore, we concluded that the combination of these two methods (50 nM PXD101 treated for 10 hours after SCNT and then aggregated at four-cell stage) is considered as the optimal way for the in vitro development of SCNT embryo and subsequent NT-ESCs isolation in mice, providing a new approach for the practical improvement of mouse cloning techniques and opening new opportunities to improve cloning efficiencies in other species.