Trichostatin A Promotes the Development of Bovine Somatic Cell Nuclear Transfer Embryos

We studied the effects of trichostatin A (TSA), a histone deacetylase inhibitor, on the development of bovine somatic cell nuclear transfer (SCNT) embryos by investigating (1) the optimal concentration and treatment time of TSA for development of bovine SCNT embryos, (2) the status of histone acetylation in TSA-treated and control SCNT embryos and (3) the expression of histone acetylation- and deacetylation-related genes in TSA-treated and control SCNT embryos. We observed that 50 nM TSA-treatment for 20 h following fusion resulted in more efficient in vitro development of bovine SCNT embryos to the blastocyst stage. In regard to histone H4K5 acetylation, half of the control SCNT embryos faintly displayed histone H4K5 signals 30 min after electrofusion, while most of the TSA-treated SCNT embryos displayed histone H4K5 signals within 30 min after electrofusion. Furthermore, the expressions of HDAC1 and HDAC2 in the blastocysts were significantly lower (P<0.05) in the TSA-treated SCNT than in the control SCNT. However, the expression of GCN5 and HAT1 did not differ between the TSA-treated and control SCNT. In conclusion, we demonstrated that TSA-treatment after SCNT in bovine embryos can dramatically improve the practical applications of current cloning techniques.