P-67: Quantitative Expression of Pluripotency Specific-Genes in Mouse Blastocysts Produced by In Vitro Fertilization

Background: The efficiency of in vitro fertilization (IVF) is still low to be developed to blastocyst stage probably because of environmental conditions. It is likely that in vitro environment can not exactly mimic in vivo environment due to differences in media, metabolic content, atmospheric composition, temperature and pH. Therefore it may affect embryo quality by changing in embryo gene expression. In this study, the expression level of pluripotency specific-genes: Oct4, Nanog and Sox2 were assessed in mouse blastocysts produced by IVF and compared with the control blastocysts flushed out of uterus on post coital day 3.5. Materials and Methods: Matured mouse oocytes were fertilized using capacitated sperms in HTF medium. Subsequently, presumptive zygotes were cultured for 4 days in KSOM medium up to the blastocyst stage. The expression levels of three mentioned genes were assessed by real-time PCR technique in IVF-derived blastocysts as treated group and in vivo collected blastocysts as control group. Results: Hatching rate of IVF-derived blastocysts was decreased significantly in comparison with the counterpart group (70.22% vs. 87.80%). Increase in Oct4, Nanog and Sox2 expression was observed in IVF versus in vivo generated mouse embryos. Conclusion: In vitro produced embryos followed by assisted hatching can be introduced as a reliable technique to help infertile couples.