Alterations in gene expression and DNA methylation in the bovine blastocyst caused by culture with choline chloride

ABSTRACT: Exposure of the preimplantation bovine embryo to choline programs development to alter postnatal phenotype of the resultant calves. To understand potential mechanisms, actions of choline on gene expression and DNA methylation of the bovine blastocyst were characterized. Embryos produced in vitro using oocytes collected by oocyte pickup procedures were cultured for 7 days with either 1.8 mM choline chloride or vehicle (consisting of 1.8 mM additional NaCl). Using an adjusted p of 0.05, the total number of differentially expressed genes (DEG) was 263 with 208 downregulated by choline. Analysis of gene ontologies of differentially expressed genes indicated choline causes reduced protein synthesis. DNA methylation was determined from another set of bovine blastocysts using whole genome enzymatic methyl sequencing. A total of 7,983 differentially methylated regions (DMR) were identified, with 6,174 hypermethylated (choline>vehicle) and 1,809 hypomethylated. Thus, as expected given its role as a methyl donor, the major action of choline was to promote methylation. The correlation coefficient between DNA methylation percent in promoters and gene expression was -0.21 for both vehicle and choline groups. Comparison of a DNA methylation data set of blood cells from heifers derived from choline- or vehicle-treated embryos identified 13 overlapping DMRs for the blastocyst and blood datasets where direction of methylation (hyper- or hypomethylated) was the same for blastocysts and blood. It was concluded that choline alters blastocyst gene expression in a manner consistent with reduced protein synthesis and causes small changes in DNA methylation. Moreover, a small number of DMR are retained into the postnatal period. Keywords: blastocyst, cattle, DNA methylation, gene expression, nutrient

ORGANISM(S): Bos taurus

PROVIDER: GSE320000 | GEO | 2026/03/31

REPOSITORIES: GEO