In vitroageing of pig oocytes: effects of the histone deacetylase inhibitor trichostatin A

Abstract

SummaryAfterin vitromaturation, the unfertilized pig oocytes underwent the process called ageing. This process involves typical events such as fragmentation, spontaneous parthenogenetic activation or lysis. Inhibition of histone deacetylase, using its specific inhibitor trichostatin A (TSA), significantly delayed the maturation of pig oocytes culturedin vitro. The ageing of oocytes matured under the effect of TSA is the same as the ageing in oocytes matured without TSA. The inhibition of histone deacetylase during oocyte ageing significantly reduced the percentage of fragmented oocytes (from 30% in untreated oocytes to 9% in oocytes aged under the effect of 100 nM of TSA). Oocytes maturedin vitroand subsequently aged for 1 day under the effects of TSA retained their developmental capacity. After parthenogenetic activation, a significantly higher portion (27% vs. 15%) of oocytes developed to the blastocyst stage after 24 h ageing under 100 nM TSA when compared with oocytes activated after 24 h ageing in a TSA-free medium. The parthenogenetic development in oocytes aged under TSA treatment is similar to the development of fresh oocytes (29% of blastocyst) artificially activated immediately afterin vitromaturation.