Establishment and proliperation of parthenogenetic embryonic stem cells on the mouse

Abstract

Mouse parthenogenetic embryonic stem cells (PgESCs) are considered as alternative of ESCs for research, which could be applied to study imprinting genes and are used in cell therapy. However, the establishment of PgESCs is still limited in low rate of establishment due to abnormal gene expression, and there is no previous report in ICR mouse. From that reason, we try to establish PgESCs in this mouse strain by following available ICR mice source and its difficulties in the parthenogenesis. Many previous study had succeed on establish PgESCs of inbred and hybrid mice by aggregation of 4 cell embryos together. Therefore, we propose that aggregation may improve ability to successfully establish PgESCs on this mouse strain. To verify this hypothesis, aggregation of four parthenogenetic embryos together at the 4-cell stage and cultured to the blastocyst stage, following ESc culture of those. Aggregation did not show a significant difference in pre-implantation development, however quality of blastocyst by cell number assessment strongly increased up to 2.5 times to normal parthenogenetic blastocyst and taken much higher isolation efficiency of aggregated PgESCs which derived from aggregated parthenogenetic blastocyst then those of non-aggregation. In conclusion, embryos aggregation improves blastocyst quality and overcomes those hardness of parthenogenetic embryonic stem cell isolation in ICR strain. It implied that aggregation could serve as a better scientific model applied in imprinting gene and regenerative medicine study. Key words: parthenogenesis, aggregation, embryonic stem cells.