Transcriptomic Analysis of the Porcine Endometrium during Embryo Implantation

Abstract

In pigs, successful embryo implantation is an important guarantee for producing litter size, and early embryonic loss occurring on day 12–30 of gestation critically affects the potential litter size. The implantation process is regulated by the expression of numerous genes, so comprehensive analysis of the endometrium is necessary. In this study, RNA sequencing (RNA-Seq) technology is used to analyze endometrial tissues during early pregnancy. We investigated the changes of gene expression between three stages (day 12, 18, and 25) by multiple comparisons. There were 1557, 8951, and 2345 differentially expressed genes (DEGs) revealed between the different periods of implantation. We selected several genes for validation by the use of quantitative real-time RT-PCR. Bioinformatic analysis of differentially expressed genes in the endometrium revealed a number of biological processes and pathways potentially involved in embryo implantation in the pig, most noticeably cell proliferation, regulation of immune response, interaction of cytokine-cytokine receptors, and cell adhesion. These results showed that specific gene expression patterns reflect the different functions of the endometrium in three stages (maternal recognition, conceptus attachment, and embryo implantation). This study identified comprehensive transcriptomic profile in the porcine endometrium and thus could be a foundation for targeted studies of genes and pathways potentially involved in abnormal endometrial receptivity and embryo loss in early pregnancy.

Seminal Plasma Modifies the Transcriptional Pattern of the Endometrium and Advances Embryo Development in Pigs

“…Multiple studies of the endometrial transcriptome during the peri-implantation period, including comparisons of transcriptomic profiles in pregnant and non-pregnant animals have been carried out. In all of these studies, alterations in the expression of genes related to the immune response have been identified (35)(36)(37)(38). However, endometrial receptivity is also crucial for the adequate progression of pregnancy during preimplantation period and is highly influenced by processes involving changes in cytokines and other molecules secreted into the luminal fluid (39,40).…”

Investigation of Eph‐ephrin A1 in the regulation of embryo implantation in sows

“…Embryo implantation, also known as embryo attachment, is critical for successful pregnancies in pigs. Approximately 20%–30% of embryonic/foetal death occurred during this period (Su et al, ; Wang, Fu, & Wang, ; Wu, Wang, Li, Fu, & Zhao, ), which is the main cause of piglet loss in the pig industry (Fu et al, ; Geisert & Schmitt, ; Lin et al, ). Reducing piglet losses and increasing litter sizes are major concerns of swine producers, while the embryo implantation is an important factor affecting the litter size and the litter weight of pigs (Fu, Li, Li, Fang, & Ren, ).…”

Differential gene expression of Eph‐ephrin A1 and LEPR‐LEP with high or low number of embryos in pigs during implantation

“…Litter size is one of the most significant reproductive traits due to its economic value to the swine industry (Lee et al., ; Zhang et al., ). Litter size results from a sequence of events starting with ovulation rate, fertilization rate, embryo survival and uterine capacity (Lin et al., ). Significant limits to litter size have occurred as a result of embryo losses before and during embryo implantation (Fu et al., ; Geisert & Schmitt, ; Lin et al., ; Wu, Wang, Li, Fu, & Zhao, ).…”