Molecular fingerprint of in vitro produced bovine embryos with high competence to establish pregnancy

The objective of the current experiment was to identify the transcriptome profile of in vitro-derived embryos with high competence to establish and maintain gestation and in vitro-derived embryos treated with CSF2. Using P < 0.01 and a fold change > 2-fold or < 0.5 fold as cut-offs, there were 617 differentially expressed genes (DEG) between embryos that survived to day 30 vs those that did not, 470 DEG between embryos that survived to day 60 and those that did not, 432 DEG between embryos that maintained pregnancy from day 30 to day 60 vs those where pregnancy failed after day 30, and 635 DEG regulated by CSF2, regardless of pregnancy outcome. For each comparison, pathways and ontologies in which DEG were overrepresented included many related to cellular responses to stress and cell survival. Embryos produced with X-sorted sperm were cultured from day 5 to day 7 in serum-free medium containing 10 ng/ml recombinant bovine CSF2 or vehicle. The CSF2 was administered because this molecule can increase blastocyst competence for survival after embryo transfer. Blastocysts were harvested on day 7 of culture and manually bisected. One demi-embryo from a single blastocyst was transferred into a synchronized recipient and the other half was used for RNA-seq analysis by Illumina next-seq. Recipients were diagnosed for pregnancy at day 30 and 60 of gestation.