The histone deacetylase inhibitor Scriptaid improves in vitro developmental competence of ovine somatic cell nuclear transferred embryos

Although the success rate of sheep cloning remains extremely low, using a histone deacetylase (HDAC) inhibitor to increase histone acetylation in SCNT embryos has significantly enhanced developmental competence in several species. The objective was to determine whether HDAC inhibitors trichostatin A (TSA) and the novel inhibitor Scriptaid enhance cloning efficiency in sheep cumulus cell (passage 2) reconstructed embryos. In this study, 0.2 μmol/L Scriptaid yielded a high blastocyst development rate, almost twice that of the untreated group (25/103 [24.3%] vs. 12/101 [11.9%]; P < 0.05). Furthermore, 0.2 μmol/L Scriptaid was more effective than 0.05 μmol/L TSA in terms of the blastocyst percentage for cloned ovine embryos in vitro (17/66 [25.7%] vs. 11/65 [16.8%]; P < 0.05). Furthermore, treatment with Scriptaid increased acetylation (compared with the Control, P < 0.05) at lysine residue 12 of histone H4 (acH4K12) and lysine residue 9 of histone H3 (acH3K9) in one-, two-, four-, and eight-cell stages, as well as blastocyst stages, in cloned embryos. In conclusion, Scriptaid was more effective than TSA to enhance in vitro developmental competence in ovine SCNT embryos; furthermore, Scriptaid improved epigenetic status.