MiRNA Profiling in Plasma Exosomes of Pregnant Cows on Day 16

Plasma exosomes have been identified to be involved in embryo development and implantation. In this study, the plasma exosomes of seven pregnant cows on day 16 and seven non-pregnant cows were collected. Exosome miRNA profiles were revealed by RNA sequencing technology and the abundance of exosome miRNA between them were compared. Seven miRNAs were significantly differently expressed (p-value < 0.05, |log2(FoldChange)| > 1), with five miRNAs upregulated and two downregulated in the pregnant cow group. The most significant miRNA was bta-miR-136 (downregulated in pregnant cows, p-value < 0.005). A total of 5828 target genes were computationally predicted for the seven miRNAs. GO and KEGG enrichment analyses showed these targets were significantly involved in several biological processes and pathways associated with embryo implantation and endometrial development, such as cell adhesion, cell junction, focal adhesion, Ras signaling pathway and Rap1 signaling pathway. This study identifies seven differentially expressed plasma exosomes miRNAs on day 16 of pregnancy in cows, with bta-miR-136, bta-miR-199b, and bta-miR-382-3p emerging as candidate miRNAs for future studies on maternal-fetal communication and embryo implantation.