Comparison of Blastocyst Development between Cat-Cow and Cat-Pig Interspecies Somatic Cell Nuclear Transfer Embryos Treated with Trichostatin A

Abstract

We previously demonstrated that the histone deacetylase inhibitor, trichostatin A (TSA), improves the development of cat-cow interspecies somatic cell nuclear transfer (iSCNT) embryos. In this study, we investigated if 50 nM TSA treatment for 24 h would improve the rate of embryo development to the blastocyst stage in cat-pig iSCNT embryos, compared with cat-cow iSCNT embryos under same treatment. Despite the SCNT technique (Piezo technique) differing from our previous study (conventional technique), we confirmed that TSA supplementation at 50 nM improved the development of cat-cow iSCNT blastocysts. Porcine oocytes showed the capability to support cat iSCNT embryo development up to the blastocyst stage without TSA treatment although bovine oocytes did not. The blastocyst developmental rate of TSA treated cat-pig iSCNT embryos was significantly lower than that of the non-treated groups (0.68 and 7.95%, respectively, p < 0.05). We used in vitro-fertilized (IVF) porcine embryos to compare the effects of acetylation levels on H3K9 between cat-pig iSCNT embryos and naturally fertilized embryos. We found no differences in acetylation levels of H3K9 between the TSA treated and non-treated iSCNT groups, and the levels were lower than that of IVF embryos. In conclusion, the effects of TSA treatment on iSCNT embryo production were found to be species-specific and dependent on individual characteristics.