Study on Lysophosphatidic Acid in Activating Formation of Blastocoel in Porcine Embryos In Vitro

Abstract

Modifications to culture media, which include the addition of various factors, are important for the in vitro production (IVP) of oocytes and embryos. In this study, we investigated the effects of lysophosphatidic acid (LPA) on porcine embryo development. Porcine parthenogenetic embryos were cultured with 0, 0.1, 1, and 10 μM LPA (0 LPA, 0.1 LPA, 1 LPA, and 10 LPA) for 7 days or cultured in basic medium until day 4 and then treated with LPA from day 4 to 7. We found no difference in the in vitro development of embryos cultured with LPA for 7 days. However, the rates of blastocyst and over-expanded blastocyst formation were higher in the 0.1 and 1 μM LPA-treated groups from day 4 to 7 than in the other groups. Moreover, the timing for the formation of early blastocysts was shorter and the embryo size was larger in LPA-treated embryos than in the control. In addition, the expression of connexin 43 and gap junction and cell adhesion-related gene (GJC1 and CDH1) increased in treated embryos compared with control. Although there was no difference in the total cell number in blastocysts between groups, the apoptotic index was lower in the LPA-treated group than in the control. Furthermore, BCL2L1 increased but BAK decreased in the LPA-treated group. These results indicate that the addition of LPA to the medium from day 4 to 7 improves blastocyst formation and would be helpful in the development of preimplantation embryos.