To improve the isolation efficiency of parthenogenetic embryonic stem cells (pESCs) in mice, it is necessary to optimize the method to increase in vitro developmental competence of mice parthenogenetic blastocysts. Therefore, this study aims to investigate an optimal method for the production of mouse parthenogenetic blastocysts and isolation of pESC colonies by comparing the effects of two methods: (1) the treatment of histone deacetylase inhibitor PXD101 before, during, or after parthenogenetic activation; (2) parthenogenetic embryo aggregation; and (3) their combination treatment. The results suggest that application of PXD101 treatment and embryo aggregation could both improve the development of mouse parthenogenetic blastocysts (50 nM PXD101 treated 4 hours during activation and further 4 hours after activation: 40.0% vs. 20.0%; p < 0.05; two-cell embryo aggregation: 38.3% vs. 20.0%; p < 0.05) and also enhance the isolation rate of pESC colonies (PXD101: 33.3% vs. 11.8%; p < 0.05; two-cell embryo aggregation: 36.4% vs. 11.8%; p < 0.05). The combination of their treatments had the higher rate of parthenogenetic blastocyst development (41.7%) and significantly higher rate of pESC colony isolation from parthenogenetic blastocysts (45.0%); therefore, we concluded that the combination of these two methods (50 nM PXD101 treated for 8 hours and then aggregated at two-cell stage with 0.25% pronase for 10 minutes in our self-made concave) is considered the optimal way for the in vitro development of parthenogenetic blastocysts and subsequent pESC colony isolation in mice, opening new opportunities for application of this combination method to improve the parthenogenetic embryo development in other species.
Keywords: embryo aggregation; histone deacetylase inhibitor; pESC colonies; parthenogenetic embryos.