Trichostatin A Improves Preimplantation Development of Bovine Cloned Embryos and Alters Expression of Epigenetic and Pluripotency Genes in Cloned Blastocysts

Abstract

We investigated the effects of exposure time and concentration of trichostatin A (TSA) on in vitro development and quality of bovine SCNT embryos. At multiple time points, the relative expression of genes related to pluripotency and reprogramming was analyzed in order to assess the quality of preimplantation embryos cultured in media with TSA using real-time PCR. Development into blastocysts was higher in 100 nM TSA than in controls (35.96 vs. 28.30%, P<0.05). Study of 100 nM TSA exposure time showed development into blastocysts was higher during both short-term and long-term exposure than in controls (36.17 and 34.04 vs. 23.45%), but there was no significant difference between TSA groups. Nanog expression in blastocysts after long-term TSA exposure was similar to that in IVF blastocysts and greater than in controls and short-term exposed embryos. The Oct4 levels in the short-term exposure group were similar to those of IVF blastocysts, while Oct4 expression in long-term exposed embryos was significantly higher than in other groups. Measurement of DNMT1 and HDAC1 in blastocysts showed a similar expression profile among IVF and TSA groups regardless of treatment duration. In conclusion, this study suggests that TSA treatment after SCNT in bovine embryos can improve in vitro development of embryos by increasing the blastocysts formation and positive reprogramming of the reconstructed embryo genome caused by downregulation of DNA methylation and up-regulation of pluripotency.