Effect of Sphingosine-1-Phosphate on In Vitro Maturation of Porcine Oocytes

Sphingosine-1-phosphate(S1P) is one of the sphingolipid metabolites which affect a variety of cellular processes including the proliferation, differentiation, growth, survival, migration and gene expression. The present study was undertaken to investigate the effect of SIP on nuclear maturation of porcine oocytes. In vitro maturation frequency of porcine oocytes were compared in three different media; group Ⅰ: NCSU23＋0.1% PVA, group Ⅱ: NCSU23＋10% PFF(porcine follicular fluid), and group Ⅲ: NCSU23＋10% PFF＋10 ng/㎖ EGF＋2.5 mM β-mercaptoethanol. Each group containing 0.1 ㎎/㎖ cysteine was divided into 4 sub-groups of SIP concentration(0, 50, 500 and 5000nM). Porcine oocytes were incubated in each maturation medium supplemented with hormones(10 IU/㎖ PMSG and 10 IU/㎖ hCG) for 22h and then further cultured in the same medium without the hormones for 22h. After completion of in vitro maturation, the oocytes were fixed and stained to examine nuclear maturation by using a rapid stain method. In the group Ⅰ, the proportions of metaphase Ⅱ stage among oocytes cultured in 0nM(control), 50 nM, 500nM and 5000nM S1P were 45.5%, 66.7%, 56.6% and 48.7%, respectively. (omitted)