Embryo gene expression in pig pregnancy

Abstract

Pregnancy is a complex process which significant changes occurring continually in both the corpora lutea and in the endometrium of the females and varies depending on the embryonic, pre-implantation, or foetal stages. In the embryonic stages, the majority of genes expressed in the pig embryo correspond to the loss of cellular pluripotency. In contrast, the implantation consists of three phases: elongation of the conceptus, adhesion, and union of the embryo to the endometrial epithelium. During these phases, many factors are expressed, including growth factors, molecules that facilitate adhesion, and cytokines, among others. All these changes are ultimately regulated by different lipid and hormonal substances, specifically by progesterone, oestradiol, and prostaglandins, which regulate the expression of many proteins necessary for the development of the embryo, endometrial remodelling, and embryo-maternal communication. This paper is a review of primary gene regulatory mechanisms in pigs during different stages of implantation.