Assessment of Quality and Expression of Trophectoderm Specific Genes Cdx2 and Eomes in Collapsed Vitrified Blastocyst

Cryopreservation of embryos at different stages of development, including zygote, early cleavage and blastocyst stage is one of the main sections of in vitro fertilization programs. For better coordination of embryo and endometrium and also higher implantation rate, it is preferable to cryopreserved blastocyst than other stages. During cryopreservation, however, presence of blastocoelic fluid causes serious embryo damage, by ice crystal formation. Therefore in this study, the blastocoelic fluid was removed by a mechanical microneedle procedure and then quality of blastocysts was assessed by cellular and molecular methods. For this purpose, 421 of the NMRI mouse IVF produced blastocysts, randomly divided into three groups. The first group after placing in cryopreservation media, immersed in liquid nitrogen by cryotop and then thawed. The second group after artificial collapse techniques was immediately vitrified-thawed. Then both groups in terms of survival, hatching and gene expression compared with results of the third group (control). Comparison of the results showed that non-significant reduction in survival rate and significant reduction in hatching rate was occurred after vitrification. By puncturing the blastocoelic cavity before vitrification, hatching rate was significantly increased. Also Eomes and Cdx2 expression after the artificial collapse were reduced in compared with vitrification, but this result was closer to control genes expression (p.