Transcriptomic Signatures of the Foetal Liver and Late Prenatal Development in Vitrified Rabbit Embryos

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genomics

Background:

• Assisted reproduction technologies (ARTs) are widely used but require ongoing safety evaluation.
• Embryo vitrification, a common ART procedure, deviates from natural development and may impact fetal and postnatal physiology.
• Previous studies indicated potential postnatal risks, necessitating investigation into early-life effects.

Purpose of the Study:

• To determine if hepatic transcriptome and metabolome alterations observed postnatally are already present in fetal livers at the end of gestation.
• To compare the effects of fresh versus vitrified embryo transfer on fetal development and liver gene expression in rabbits.

Main Methods:

• Comparison of fresh and vitrified rabbit embryos.
• Analysis of fetal and liver weights, and crown-rump length at 24 days of gestation.
• RNA-sequencing (RNA-Seq) to identify differentially expressed genes (DEGs) in fetal livers.

Main Results:

• Vitrified embryo transfer resulted in reduced fetal and liver weights and crown-rump length at 24 days of gestation.
• A compensatory growth trend was observed in vitrified embryo offspring near term.
• RNA-Seq identified 43 DEGs in fetal livers, primarily involved in lipid metabolism and immune/inflammatory responses.

Conclusions:

• Embryo vitrification and transfer induce observable adaptive responses in the fetal liver during late gestation.
• These hepatic changes suggest potential impacts on lipid metabolism and immune function early in development.
• Further research is warranted to fully understand the long-term implications of ART-induced fetal adaptations.