Unveiling how vitrification affects the porcine blastocyst: clues from a transcriptomic study.

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genomics

Background:

• Efficient pig embryo cryopreservation is crucial for the porcine industry, genetic diversity, and research.
• Vitrification (VIT) is the most effective method, but in vivo embryo survival post-transfer remains variable.
• The specific effects of VIT on porcine embryonic gene expression are not fully understood.

Purpose of the Study:

• To investigate the specific gene expression alterations caused by VIT in pig embryos.
• To differentiate VIT-induced changes from those caused by in vitro culture (IVC).
• To identify potential biomarkers for improving pig embryo vitrification.

Main Methods:

• RNA-sequencing was performed on three groups of pig blastocyst-stage embryos: VIT (vitrified/warmed and IVC), IVC (in vitro cultured control), and CO (in vivo control).
• Differential gene expression analysis was conducted to compare mRNA profiles between groups.
• Functional enrichment analysis was used to identify biological pathways affected by VIT and IVC.

Main Results:

• Distinct mRNA profiles were observed for VIT, IVC, and CO embryos.
• VIT-specific alterations were linked to osmotic stress response, hormone response, and developmental growth.
• Hypoxia and mitophagy alterations were associated with the combined effects of VIT and IVC.

Conclusions:

• This study provides novel insights into VIT-specific embryonic gene expression changes.
• Identified VIT alterations may represent cryodamage signatures or embryo healing responses.
• Validated genes show potential as biomarkers to enhance pig embryo vitrification protocols.