Lysophosphatidic acid (LPA) is an important signaling molecule. Here, the effect and mechanism of LPA on the preimplantation development of porcine embryos during in vitro culture (IVC) was examined. Porcine embryos were cultured in porcine zygote medium (PZM-3) supplemented with 30 μM LPA during different days. There was a significantly higher cleavage rate in Day 1-7 and significantly higher total cell number of blastocysts in Day 1-3 and Day 4-7. It was also found that messenger RNA (mRNA) expression level of PCNA, BCL2 and BAX in blastocysts obtained from D1-7 group were significantly higher and BCL2/BAX mRNA ratio in D1-3 group was significantly lower than control group but Day 4-7 and Day 1-7 groups were comparable with control group. Treatment with 20 μM PLC inhibitor significantly decreased the embryo cleavage rate and blastocyst formation rate. Moreover, LPA as an activator of PLCs, enhanced the 30 μM LPA + 20 μM U73122 group embryo cleavage rate which similar with control group. In conclusion, the results suggest that treatment with LPA during IVC improves the porcine early embryo cleavage by activation of PLC signaling pathway and regulate the mRNA expression that contribute to total cell number of blastocysts during blastocyst formation.

INTRODUCTION
 MATERIALS and METHODS
  1. Chemicals
  2. Oocyte collection and in vitro maturation (IVM)
  3. In vitro fertilization (IVF) and in vitro culture (IVC)
  4. Embryo evaluation and total cell count of blastocysts
  5. Quantitative real-time polymerase chain reaction (qRT-PCR)
  6. Experimental design
  7. Statistical analysis
 RESULTS
  1. Effects of LPA-supplemented IVC media on embryonic development after IVF
  2. Effects of LPA treatment during IVC on gene expression in blastocysts
  3. Effects of phospholipase C inhibitor, U-73122, treatment on IVF-derived embryo development
  4. Effects of U73122 and LPA co-treatments on porcine pre-implantation embryonic development
 DISCUSSION
 REFERENCES

• Minghui Jin(Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), College of Veterinary Medicine, Chungbuk National University)
• Il-Jeoung Yu(Department of Theriogenology and Reproductive Biotechnology, College of Veterinary Medicine and Bio-safety Research Institute, Chonbuk National University)
• Yubyeol Jeon(Department of Theriogenology and Reproductive Biotechnology, College of Veterinary Medicine and Bio-safety Research Institute, Chonbuk National University) Correspondence