Transcriptomic analysis of uterine receptivity in Guinea pigs.

The mouse is a widely used animal model for studying human reproduction. However, the mice are eccentric implantation, and ovarian progesterone and estrogen are essential for implantation, which is different from human beings. Guinea pigs are unique from mice since, like humans, they are the interstitial implantation, and ovarian progesterone alone seems to be sufficient to allow for implantation. In this study, we firstly analyzed the gene expression profiles in the receptive uterus on day 5 of pregnancy compared to the pre-receptive uterus on day 3 of pregnancy in guinea pigs using the RNA-seq method. In total, 304 up-regulated and 475 down-regulated genes were identified. Gene Ontology and pathway enrichment analyses highlighted the importance of the inflammatory response in the receptive uterus. Through gene network analysis, we identified 24 hub genes, most of which were involved in regulating endometrial receptivity. In addition, we performed a cross-species comparison of differentially expressed genes associated with uterine receptivity. A total of 14 genes were shared among guinea pigs, humans, and mice. Furthermore, Fisher's exact test revealed that gene expression patterns of uterine receptivity were more similar between guinea pigs and humans than between mice and humans. Our study may contribute to increasing the knowledge of uterine receptivity in guinea pigs.