Female fertility is a highly regulated process involving multiple tissues, and a research group led by Wageningen University & Research (WUR) showed that the transcriptomes of the porcine ovary, endometrium and oviduct share gene profile regulation during the estrous cycle.

The group, led by M.F.W. te Pas, said comprehensive understanding of the regulatory mechanism of the estrous cycle in domesticated animals is important for animal productivity and resolving reproductive problems such as infertility. Female fertility is a highly regulated process involving the synchronized activities of multiple tissues.

This is of particular interest in pigs, because reproductive rate and litter size impact commercial value, the researchers wrote in Scientific Reports.

According to WUR, the group investigated the transcriptomes of the porcine ovary, endometrium and oviduct at days 0, 3, 6, 9, 12, 15 and 18 of the estrous cycle. They analyzed the transcriptome profiles of the individual tissues and focused on the bridging genes shared by two or more tissues.

The three tissue gene-networks were connected to each other by 65 bridging genes with a high level of connectivity to all other genes in the entire network, WUR said. The expression levels showed negative correlations between the ovary and the other two tissues and low correlations between endometrium and oviduct. The main functional annotations of these bridging genes involved biosynthesis of steroid hormones, cell-to-cell adhesion and cell apoptosis, suggesting that regulation of steroid hormone synthesis and tissue viability are major regulatory mechanisms, WUR reported.

This shows that these tissues have synchronized gene expression profiles during estrous progression, the researchers concluded.

The research was published in Scientific Reports.