Effect Of Deacetylase Inhibitor Valproic Acid On Bovine Cultured Somatic Cells And Early Cloned Embryo Development

MTT and fluorescence quantitative protocols were used in this study to examine the effect of a deacetylase inhibitor valproic acid (VPA) on the development of bocine somatic cells and the cloned embryos. The main results were as following.1. The effect of VPA on cell growth of bovine fibroblastsThe bovine fetal fibroblast cells were treated with VPA at different concentrations of0,0.25,0.5,1.0,2.0and4.0mM for24h and48h, respectively. The results showed that when VPA at2mM and4mM to treat cells for24h and48h the cell growth were significantly inhibited.2. The effect of VPA on histone acetylation and methylation of bovine fibroblast cellsVPA improved the H3K9acetylation only in the treatment groups of VPA at4mM for24h and48h. When VPA at4mM and treated cells for24h, or VPA at2mM and4mM and treated cells for48h the H4K5acetylation improved.Treatment of cells with VPA decreased the H3K9metylation in all of the experimental groups.3. VPA treatment affected cell diploidyVPA affected cell chromosomal composition when the concentration reached to4mM. The diploid composition of the cells in the control group was88%, while the diploid decreased to72%when VPA was4mM.4. The effect of VPA on cell cycle and cell apoptosisWith the increase of VPA concentrations from0.25mM to4.0mM the proportions of cells at GO/G1or G2/M increased, while cells at S stage decreased. These results suggested that VPA induce the arrestment of cells at G0/G1stages.When the cells were treated with VPA at different concentrations for24h the cell early apoptosis increased. When the treatment time last upto48h the cell early apoptosis became more significant. However, the late cell apoptosis did not observed.5. Effect of VPA on cloned embryo developmentThe cells treated with VPA at0,0.25,0.5,1.0and2mM for24h or48h were used as donor cells for nuclear transfer. The cleavage and blastocyst rates were with no significant differences compared to the control. When the cells were treated with VPA at4.0mM the cleavage and blastocyst development significantly decreased (65.5%and15.5%, respectively). The blastocyst cell number was decreased with the increase of VPA concentrations.