P-47: Effect of Blastocoelic Fluid Reduction on Quality and Expression of Developmentally Important Genes in Mouse Blastocysts
Recent researches reveal that manual puncturing of the trophectoderm of blastocyst before vitrification, increase the quality of embryo. However, in any of these studies, the importance of blastocoelic fluid and its impact on the formation of three cell lines is not mentioned. Therefore, in the present study, the effect of blastocoelic fluid reduction before vitrification on survival and hatching rate, expression of lineage specific genes (Oct4, Nanog, Cdx2, Eomes and Gata6), and apoptosis related gene (P53) in mouse blastocyst was studied.
Materials and methods
For this purpose, two sources of In vitro and In vivo produced mouse embryos were used and randomly divided in to three groups. 1. Vitrified/warmed blastocysts, 2. Vitrified/warmed blastocysts after artificial collapse (AC) and 3. Fresh blastocysts as control group. The survival and hatching rates of embryos were evaluated. After total RNA extraction of three groups, Real time PCR was accomplished.
The survival rate of treatments was similar to the control group. The hatching rate of AC-vitrified/warmed blastocysts was significantly higher than that of non-AC group. The expression results of two sources were approximately similar. There was no significant change in expression of pluripotency genes (Oct4, Nanog) between vitrified/warmed and AC-vitrified/warmed blastocyst. The expression of Cdx2, Eomes, Gata6, and P53 in AC-vitrified/warmed was reduced in compared with vitrified/warmed blastocyst (P<0.05).
Considering the increase in hatching rate and decrease in the expression of P53 gene (reduction in stress) and Eomes, Cdx2 genes (reduction damage to the trophectoderm cells) in AC-vitrified/warmed group, this method could be an effective way to contribute to the successful blastocyst vitrification.