Activators of protein kinase A (PKA) signaling pathway have been frequently used to transiently stall meiosis at early phase of in vitro maturation (IVM) for balancing between cytoplasmic and nuclear maturation of mammalian embryos. Despite of the tight association of 6-diazo-5-oxo-l-norleucine (DON), an inhibitor of hyaluronan synthesis, with PKA cascade, few evidences has been provided concerning the role of DON as an IVM supplement with meiosis-stalling activity during IVM of porcine oocytes. Thus, the current study was conducted to examine the effect of DON on nuclear/cytoplasmic maturation of porcine oocytes and subsequent early embryonic development. From the observation of nucleus patterns, we found that treatment of DON successfully retarded meisis progression. Unlike the results from the treatment of 5 and 10 mM DON, IVM rate of porcine oocytes was increased only in 1 mM DON treatment group compared to control (81.9±0.1 vs 71.5±1.3, P<0.05). Consistent with this, blastocyst formation rate (44.2±1.9 vs 30.5±7.4, P<0.05) and TE proportion (34.5±3.8 vs 23.8±2.0, P<0.05) were greatly increased in 1 mM DON treatment group compared to control. Consistent with this, pathenogentic activation of MII oocytes matured under 1 mM DON greatly increased blastocyst formation rate (54.4±5.2 vs 31.5±6.1, P<0.05). From the results, we concluded that 1 mM DON can be efficiently used to massively yield MII oocytes with high nuclear/cytoplasmic maturation and developmental competence.
02 Sep 2014 - 04 Sep 2014