Different Origin, Different Response: Gene Expression Pattern in Collapsed Vitrified Blastocyst.

Area of Science:

• Reproductive Biology
• Developmental Biology
• Assisted Reproductive Technologies (ART)

Background:

• Extensive animal data exists for assisted reproductive techniques (ART), primarily from in vivo-derived embryos.
• The applicability of these findings to in vitro-derived embryos, common in clinical settings, remains a critical question.
• Vitrification (VIT) and artificial collapse (AC) are widely used ART procedures.

Purpose of the Study:

• To compare the effects of vitrification (VIT) and artificial collapse (AC) on both in vivo- and in vitro-derived mouse embryos.
• To assess survival, hatching rates, and the expression of key developmental genes in response to these techniques.

Main Methods:

• Production of both in vivo- and in vitro-derived mouse blastocysts.
• Random division into three groups: control (non-vitrified), vitrification (VIT), and artificial collapse-vitrification (AC-VIT).
• Assessment of survival and hatching rates, and real-time PCR analysis of gene expression.

Main Results:

• Both in vivo and in vitro embryos exhibited similar hatching rate patterns.
• Vitrification increased pluripotency gene expression in in vivo embryos but significantly reduced it in in vitro embryos.
• Artificial collapse decreased specific gene expression (Gata6, Grb2) in post-warmed in vivo embryos, but not in vitrified in vitro embryos.

Conclusions:

• Vitrification and artificial collapse exert differential effects on embryo development based on their origin (in vivo vs. in vitro).
• Gene expression patterns diverge significantly between in vivo and in vitro embryos following cryopreservation techniques.
• These findings highlight the importance of considering embryo origin when applying ART protocols.