This study aimed to determine the acetylation patterns on histone H3K9/18/23 and the dimethylation pattern on histone H3K9 during early embryogenesis among 50 nM Trichostatin A (TSA)-treated iSCNT cat-cow embryos, untreated iSCNT cat-cow embryos (control) and bovine in vitro fertilisation (IVF) embryos, because TSA-treated iSCNT embryos are able to develop into blastocysts. The results show that the acetylation levels of H3K9/18/23 in the TSA-treated iSCNT and bovine IVF embryos were higher than those in the control embryos at almost all of the examined stages (2 h post-fusion / post-insemination (PF/PI), pronuclear (PN), two-cell, four-cell and eight-cell stages). At 6 h PF/PI the acetylation levels on H3K9/23 in the TSA-treated iSCNT and bovine IVF embryos were lower than those in the control, and there was no difference in the acetylation levels of H3K18 among the three groups. The acetylation levels of H3K9/23 increased either in the TSA-treated iSCNT or and bovine IVF embryos increased when those embryos developed to the PN and two-cell stages. The dimethylation level of H3K9 in the TSA-treated iSCNT embryos resembled that of the bovine IVF embryos at all examined stages (2h PF/PI, 6 h PF/PI and PN stages), and these levels were greater than those of the control. This result suggests that treatment of iSCNT embryos with TSA modifies the patterns of histone acetylation and dimethylation at certain lysine residues in a manner that is comparable with that seen in IVF embryos during early embryogenesis
