P-197: Aberrant Gene Expression Profile in Blastocyst Embryos As Consequences of Assisted Reproductive Technologies

Background: Currently, ARTs are of indispensable importance in treatment of human infertility. While ARTs are considered to be safe, some studies suggest that ARTs manipulations may perturb the epigenetic information and subsequently the health of the offspring. To examine these events further, this study was conducted to assess the effect of superovulation, in vitro culture and vitrification on gene expression of several histone modifier enzymes and pluripotency factors at blastocyst stage. Materials and Methods: In this regard female mice were randomly assigned to four experimental groups: in groups control (C) and superovulation (S), blastocysts were collected on day 3.5 after in vivo fertilization and development without and with superovulation females in groups C and S, respectively. In group superovulation + in vitro culture (SI), blastocysts were obtained from superovulated females after in vivo fertilization and in vitro development in G1/G2 media from 2-cell to hatched blastocyst stage. In group superovulation + vitrified + in vitro culture (SVI) blastocysts were obtained from superovulated mice after in vivo fertilization, vitrification/ warming at 2-cell stage and in vitro development in G1/ G2 media from 2-cell to hatched blastocyst stage. Results: The mRNA expression of Mll1 and Ash1l which mediate tri-methylation of H3K4 was the highest in C group which was not significant in compare to other groups (p>0.05). The analysis of mRNA expression of Tip60 and Gcn5, which acetylate H4K12 and H3K9, respectively, revealed that the level of mRNA was significantly lower in manipulated groups in compare to control (p<0.05) except in SVI group for Tip60. The mRNA expression of pluripotent markers including Sox2 and Nanog was significantly higher in C group in compare to other groups (p<0.05). The mRNA expression of Pou5f1 was significantly higher than S group, while it was not significant for SI and SVI groups. Conclusion: ARTs manipulations may alter the epigenome of the resultant offspring.