Histone deacetylase inhibitor trichostatin A affects porcine oocyte maturation in vitro

Previous studies show that porcine oocyte aging resulting from asynchronised IVM impairs embryo developmental competence. In the present study we investigated whether trichostatin A (TSA; an inhibitor of histone deacetylation) prolongs the maturation time and prevents the aging of oocytes. Porcine oocytes were cultured in medium containing increasing concentrations of TSA (300 nM) for 24, 44 or 64 h. The percentage of oocytes that underwent germinal vesicle breakdown was significantly lower in the TSA-treated group (300 nM) than in the control group. TSA did not affect oocyte quality at MII based on levels of maturation-promoting factor, the phosphorylation status of mitogen-activated protein kinase or histone H3K9 acetylation analysis. We also compared the preimplantation developmental competence and the viability of pathenogenetic embryos treated with 100 nM TSA for 24h and then continuously cultured for another 24h in TSA free condition. No significant differences were observed for either parameter between the TSA-treated and control groups. These results indicate that TSA prolongs the IVM of porcine oocytes but that oocyte quality and aging are not affected. These findings provide a feasible option by which to adjust the initiation time of downstream experiments based on porcine matured oocytes.