Developmental Morphokinetics and the Transcriptomic Profile of Bovine First-Cleaved Embryos: Normal vs. Abnormal...

Area of Science:

• Reproductive Biology
• Embryology
• Genomics

Background:

• Early embryonic loss negatively impacts conception rates in lactating cows.
• The molecular mechanisms driving early embryonic loss remain poorly understood.
• Understanding early embryonic development is crucial for improving bovine reproductive efficiency.

Purpose of the Study:

• To investigate the association between early embryonic morphokinetics and developmental competence in vitro.
• To identify transcriptomic differences in bovine embryos exhibiting abnormal cleavage patterns.
• To explore the potential role of gene expression in early embryonic loss.

Main Methods:

• In vitro production of bovine embryos.
• Time-lapse microscopy for monitoring embryonic morphokinetics over 190 hours.
• RNA sequencing (RNA-seq) analysis of individually collected first-cleaved embryos.

Main Results:

• Embryos with abnormal cleavage (reverse, direct, unequal) had lower blastocyst development rates compared to normally cleaved embryos.
• Significant differential gene expression (672 genes) was observed between normally and abnormally cleaved embryos.
• Abnormally cleaved embryos showed altered pathways related to energy production, metabolism, and oxidative phosphorylation.

Conclusions:

• Embryonic morphokinetic patterns during early cleavage are indicative of developmental competence.
• Differential gene expression profiles in abnormally cleaved embryos may contribute to early embryonic loss mechanisms.
• Morphokinetic analysis combined with transcriptomics offers insights into bovine embryonic viability.