Effects of nanocurcumin on preimplantation development of cloned bovine embryos

Abstract

Somatic cell nuclear transfer (SCNT), a powerful tool to achieve cloned embryos is applied widely around the world in order to create cloning organisms for conservation, transgenic animal productions or bio-organ transplantation, etc. However, the success rate of this technique until now is still very low, and abnormal epigenetic modification is known as one of the main reasons. Therefore, a culture system which is able to prevent the epigenetic errors during the development of cloned embryos is extremely necessary. In this study, we intended to assess the impacts of nanocurcumin (NC), a very new histone deacetylase inhibitor (HDACi) on the pre-implantation development of the cloned bovine embryos. Specifically, the bovine mature oocytes or reconstructed oocytes created by somatic cell nuclear transfer (SCNT) were activated and in vitro cultured for embryo development in the presence of different concentration of NC (1M, 5M, 10M) and duration time (0-24h, 0-48h, 72-82h). Embryos development status among groups were compared from the zygote formation to the 16-cell stage based on survival rates and levels of histone acetylation (HAc) signals. In this study, the results showed that increasing the concentration of NC from 1M to 10M caused toxic the embryos. However, the cloned embryos treated with 1M NC for 36-48h and 72-82h increased the level of HAc at 4-cell stage and 8-cell stage embryo, respectively. And the treatment of NC 1M for 48h improved the developmental rates of cloned bovine embryos compared to the control group. At pronuclear formation stage, no signal of HAc was observed in the cloned embryo. In conclusion, although high concentration NC may affect the preimplantation development rates of the embryos, its impacts on HAc from 4-cell stage were recorded. Thus, using NC at suitable concentration and timing may improve the preimplantation development of cloned bovine embryos for further process. Keywords: nanocurcumin (NC), somatic cell nuclear transfer (SCNT), cloned bovine embryos, parthenogenetic embryos, histone acetylation (HAc), preimplantation development.