Aggregation of a parthenogenetic diploid embryo and a male embryo improves the blastocyst development and parthenogenetic embryonic stem cell derivation

Parthenogenetically derived mammalian embryos, with no paternal genome, are not viable and die, largely from defective placental growth attributed to a lack of paternal effect, resulting in the low blastulation rate and low derivation efficiency of parthenogenetic embryonic stem cells (pESCs). Therefore, the present study, by the optimization of parthenogenetic embryo production and the aggregation of the parthenogenetic diploid embryo and the identified male embryo, aims to investigate a method to improve the development of parthenogenetic embryo and pESC derivation in mice. Using different chemical combinations for the optimization, we found that the heterozygous diploid type had a significantly higher blastulation rate than the haploid type (P < 0.05). The treatment of strontium chloride (SrCl2) combined with cytochalasin B for 4 h produced the highest heterozygous diploid rate and blastulation rate. Our self-made concave hole system was used for the aggregation of the parthenogenetic heterozygous diploid embryo with the male embryo identified by the duplex PCR method, and we found that the chimeric embryo had an improved rate of blastulation and pESC isolation.