Tannin Supplementation Improves Oocyte Cytoplasmic Maturation and Subsequent Embryo Development in Pigs

Abstract

To investigate the effects of tannins (TA) on porcine oocyte <i>in vitro</i> maturation (IVM), different concentrations of TA (0, 1, 10 and 100 μg/mL) were supplemented with a maturation medium and the COCs and subsequent embryonic development were examined. The results showed that 10 µg/mL TA significantly improved the cumulus expansion index (CEI), cumulus-expansion-related genes (<i>PTGS1</i>, <i>PTGS2</i>, <i>PTX-3</i>, <i>TNFAIP6</i> and <i>HAS2</i>) expression and blastocyst formation rates after parthenogenetic activation (PA), <i>in vitro</i> fertilization (IVF) and somatic cell nuclear transfer (SCNT) compared to the control groups, but not oocyte nuclear maturation. Nevertheless, 10 µg/mL TA dramatically enhanced the mRNA expression of oocyte-development-related genes (<i>BMP15</i>, <i>GDF9</i>, <i>CDC2</i> and <i>CYCLIN B1</i>), GSH, ATP, SOD1, PGC1α, BMP15, GDF9 and CDC2 levels and reduced intracellular ROS level in porcine oocytes. These results indicated that porcine oocyte cytoplasmic maturation was improved by 10 µg/mL TA treatment during IVM. In contrast, a high concentration of TA (100 μg/mL) significantly decreased the CEI and <i>PTGS1</i>, <i>PTGS2</i>, <i>PTX-3</i> and <i>HAS2</i> mRNA expressions in cumulus cells, and reduced oocyte nuclear maturation and the total cell numbers/blastocyst. In general, these data showed that 10 μg/mL TA supplementation has beneficial effects on oocyte cytoplasmic maturation and subsequent embryonic development in pigs.