The purpose of this study is the effects of growth differentiation factor 8 (GDF8) and SB431542 (SB) on porcine oocytes in vitro maturation (IVM), subsequent embryonic development after in vitrofertilization (IVF). We were investigated the effect of GDF8 and SB treatment during IVM on nuclear maturation, intracellular glutathione (GSH), reactive oxygen species (ROS) levels, analyzed specific gene transcription and translation levels in cumulus cells after IVM, and embryonic development and transcription pattern after IVF. Data were analyzed by on way ANOVA. The 1.318 ng/ml of GDF8 and 5 ng/ml of SB were added during IVM followed experiment design as control, SB, SB+GDF8, and GDF8 treatment groups. After 44 h of IVM, GDF8 group (90.4%) showed significantly increased nuclear maturation than other groups (85.4, 78.9, 85.4 and 90.4%, respectively), and SB group showed significantly lower maturation than control (P<0.05). The GDF8 group showed significantly (P<0.05) decreased intracellular ROS and increased GSH levels compared with other groups. SB+GBF8 group showed significantly better cytoplasmic maturation than SB group. The GDF8 group showed highly increased PCNA and Nrf2 and cumulus expansion factors COX-2, Has2, Ptx3 and TNFAIP6 mRNA transcription level in cumulus cells after IVM. In protein expression level, GDF8 group showed significantly increased phosphorylated SMAD 2/3 per SMAD 2/3 ratio than control (P<0.05). In IVF embryonic development, GDF8 group showed a significantly (P<0.05) higher blastocyst total cell number compared with control and SB groups (87.2, 93.9, and 119.4 respectively). The gene expression level showed in IVF BL, the developmental competence marker PCNAand POU5F1 transcription levels were tended to increase in GDF8 group compared with control (0.05<P<0.1). In conclusion, treatment of GDF8 during IVM significantly improved the IVF embryo developmental competence and effected on transcription pattern, and redeemed developmental potential from SB inhibition by increasing P-SMAD2/3 level.
Acknowledgement: This work was supported by a grant from the Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ011288) Rural Development Administration, Republic of Korea.
11 Jul 2016 - 11 Jul 2016