Histone deacetylation is required for orderly meiosis.

Histone acetylation is associated with a diversity of chromatin-related processes in mitosis. However, its roles in mammalian oocyte meiosis are largely unknown. In the present study, we first investigated in detail the acetylation changes during porcine oocyte maturation using a panel of antibodies specific for the critical acetylated forms of histone H3 and H4, and showed meiosis stage-dependent and lysine residue-specific patterns of histone acetylation. By using trichostatin A (TSA), a general inhibitor of histone deacetylases (HDACs), we further determined that selective inhibition of histone deacetylation (thereby maintaining hyperacetylation) delayed the onset of germinal vesicle breakdown and produced a high frequency of lagging chromosomes or chromatin bridges at anaphase and telophase I (AT-I), suggesting that histone deacetylation is required for orderly meiotic resumption and accurate chromosome segregation in porcine oocytes. In addition, we examined the localization and expression of HDAC1 by performing immunofluorescence and immunoblotting analysis. The results showed that subcellular translocation, expression level and phosphorylated modification of HDAC1 were temporally regulated and likely to coparticipate in the establishment of histone acetylation profiles in oocyte meiosis.