Predicting of molecules mediating an interaction between bovine embryos and uterine epithelial cells

Embryo-maternal reproductive tract interactions are pivotal for successful pregnancy. The present study predicted the molecules modulating embryo-uterine communication by comparing two sets of differentially expressed genes (DEGs): DEGs in uterine epithelial cells (UECs) collected from the uterus with and without blastocysts and DEGs between blastocysts developed in vivo and in vitro. Cows were subjected to super ovulation (SOV), followed by insemination or non-insemination at estrus (SOV + AI and SOV cows). Seven days after estrus, the uterus was flushed to collect UECs, and the presence of blastocysts in the uterus was confirmed. UECs were subjected to RNA-Sequencing (RNA-Seq) to identify DEGs. Publicly available RNA-Seq data of in vivo and in vitro developed bovine blastocysts were used to determine DEGs. Then, using ingenuity pathway analysis, activated- and inhibited-upstream regulators (USRs) for UECs in blastocysts were compared with those for blastocysts developed in vivo. RNA-Seq of UECs revealed that the DEGs were associated with immune response and cell adhesion pathways. The activated and inhibited USRs of UECs derived from SOV+ AI cows overlapped with the activated and inhibited USRs of blastocysts developed in vivo. Overlapping activated USRs include leukemia inhibitory factor, interleukin 6, fibroblast growth factor-2, transforming growth factor beta-1, and epidermal growth factor. In conclusion, the present study predicted the molecules that potentially mediate communication between the developing embryo and the uterus in vivo and prepare the uterus for pregnancy.