Expression Profiling of Circular RNAs in Early Pregnant Jianghuai Buffaloes

The long reproductive cycle of buffalo is a key factor limiting the expansion of buffalo populations. Early and accurate pregnancy diagnosis in breeding heifers can shorten calving intervals and improve reproductive efficiency. Circular RNA (circRNA) is expressed in cells and tissues of several species. However, the expression of circRNAs in the blood of Jianghuai buffaloes during early pregnancy has not been reported. In this study, we identified the differentially expressed circRNAs (DECs) in the blood of Jianghuai buffaloes and annotated the functions of these DECs. The results showed that there were 890 differentially expressed circRNAs between the pregnant and non-pregnant groups, of which more than 80% were exon-derived circRNAs, including 323 up-regulated circRNAs and 567 down-regulated circRNAs. Enrichment analysis revealed that DECs were mainly enriched in the epidermal growth factor receptor signaling pathway important for embryonic development and pregnancy maintenance. In addition, most DECs have multiple miRNA targets, suggesting that these DECs have the potential to function as miRNA sponges. In conclusion, a number of DECs are present between pregnant and non-pregnant Jianghuai buffaloes, and these DECs are associated with embryo implantation and pregnancy establishment. control buffalo and pregnancy buffalo