Effects of Sperm Extract and its Molecular Weight Fractions on Oocyte Activation in Miniature Pig Spermatozoa

抄録

This study was conducted to compare the quantity of total protein in miniature pig sperm extract (SE) extracted by two methods [sonication and a method using Mammalian Protein Extraction Reagent (M-PER)]. Furthermore, the effects of injection with SE extracted by M-PER and fractionated SE on porcine oocyte activation were examined. The total amount of protein extracted from miniature pig spermatozoa (1 × 10⁹ sperm) by M-PER was significantly (P<0.05) larger than that extracted by sonication. When the porcine oocyte activation rate after injection with SE extracted by M-PER at different protein concentrations was examined, the highest activation (31.4%) was induced by injection with 0.08 mg/ml SE, and the value was significantly (P<0.05) higher than the control (buffer injection). When the effect of injection with fractionated SE (>100 kDa and <100 kDa) was examined, the activation rates of the control (non-fraction), >100 kDa, and <100 kDa groups were 63.6, 48.7, and 46.4%, respectively. Significant differences (P<0.05) were observed between the control and <100 kDa groups. These results indicate that SE extracted by M-PER from miniature pig sperm is effective for porcine oocyte activation. Oocyte activation could be induced efficiently by injection with SE using M-PER. Both <100 kDa SE and >100 kDa SE contain effective materials for porcine oocyte activation.