Effects of scriptaid on the histone acetylation of buffalo oocytes and their ability to support the development of somatic cell nuclear transfer embryos

The present study was undertaken to investigate the effect of scriptaid treatment on histone H3 on lysine 18 (H3K18) acetylation and relative expression levels of genes related to histone acetylation (HAT1, CBP, and p300) in buffalo oocytes during IVM. Meanwhile, the embryonic developmental ability of buffalo oocytes after SCNT was also examined. The H3K18 acetylation in oocytes increased from the germinal vesicle (GV) stage to the GV breakdown (GVBD) stage and arrived at a high acetylation level at the GVBD stage. Then, the H3K18 deacetylated completely at the metaphase I (MI) and acetylated again at the MII stage. However, addition of 500-nM scriptaid to the maturation medium resulted in a significant increase in the H3K18 acetylation at the MI stage. The expression profiles of genes related to histone acetylation (HAT1, CBP, and p300) in the meiosis stages of oocytes matured in the medium supplemented with 500-nM scriptaid were significantly higher than those of the oocytes matured in the medium without scriptaid (P < 0.05) with the exception of p300 at the GVBD stage. More SCNT embryos reconstructed with oocytes matured in the medium supplemented with 500-nM scriptaid developed to blastocysts (23.1%) in comparison with oocytes matured in the medium without scriptaid (13.8%, P < 0.05). These results indicate that scriptaid can increase the histone acetylation of buffalo oocytes during meiotic maturation and improve their ability to support the development of SCNT embryos.