91 EFFECT OF LEUKEMIA INHIBITORY FACTOR (LIF) ON MATURATION OF PORCINE OOCYTES IN VITRO MATURATION AND DEVELOPMENT OF PARTHENOGENETIC EMBRYOS

Abstract

Cytokines have been suggested to have an important role for successful implantation. Among the cytokines, leukemia inhibitory factor (LIF) is a pleiotropic cytokine of the interlukin-6 family that has been confirmed for its significance in implantation in human and animal studies. Furthermore, it has been reported that LIF enhanced in vitro maturation (IVM) in cattle and sheep, blastocyst formation and hatching rate of embryos and pregnancy rate in mouse, human, cattle and sheep. However, to our knowledge, there has been no report on the effects of human LIF (hLIF) on pig oocytes IVM and embryos development. Therefore, we designed and performed this study to examine the effect of hLIF treatment on pig IVM and oocyte developmental competence. We investigated the effect of hLIF treatment during pig oocyte in vitro maturation (IVM) and in vitro culture (IVC) on parthenogenetic embryos. Three groups of different hLIF concentrations were used: 0, 0.5, and 1.0 ng mL–1. In experiment 1, hLIF was contained on IVM media, in experiment 2, hLIF was contained on IVC media for 7 days, and experiment 3, hLIF was contained on IVM and IVC media. In experiment 1, hLIF in IVM media significantly increased cleavage rate in 0.5 ng mL–1 group [hLIF 0 ng mL–1; 46.56 ± 3.1 (%), 0.5 ng mL–1; 58.43 ± 3.6 (%), 1.0 ng mL–1; 52.05 ± 2.7 (%)] and total cell number of blastocysts in hLIF 1.0 ng mL–1 group (hLIF 0 ng mL–1; 35.00 ± 2.3, 0.5 ng mL–1; 40.71 ± 3.1, 1.0 ng mL–1; 51.06 ± 3.7) but no significant differences were found in oocyte maturation rate or blastocyst formation rate. In experiment 2, total cell number of blastocysts showed significant difference in hLIF 1.0 ng mL–1 in IVC media (hLIF 0 ng mL–1; 43.81 ± 1.6, hLIF 0.5 ng mL–1; 45.97 ± 2.0, hLIF 1.0 ng mL–1; 52.10 ± 2.9). Finally, total cell number of blastocysts increased in hLIF 0.5 ng mL–1 in IVM and IVC media [hLIF 0 ng mL–1; 46.50 ± 2.3 (%), 0.5 ng mL–1; 55.11 ± 2.9 (%)]. In conclusion, hLIF supplementation to IVM and IVC medium improved porcine embryo development in terms of increasing total cell number of blastocysts. This study was supported by Korean MKE (#10033839), the Research Institute for Veterinary Science.