Intrauterine growth retardation (IUGR) in piglets was associated with DNA methylation in the promoter of renal p53 gene. The effect of maternal folic acid supplementation was investigated on kidney mRNA expression of DNA methyltransferase1 (DNMT-1), and apoptosis-related gene expressions between intrauterine growth restriction（IUGR）and normal body weight（NBW）piglets. Gilts were randomly allocated to two diets of control (C, folic acid 1.3mg/kg) or folic acid supplementation (F, folic acid 30mg/kg) diets with 12 replicates of 1 gilt each after mating. The reproductive traits of gilts were recorded and kidney samples were collected to detect gene expressions from newborn piglets of NBW and IUGR (n=8 piglets NBW and IUGR per treatment, respectively). Serum folic acid concentrations of gilts and piglets were both greater in folic acid supplementation group (P<0.01), but there were no significant differences in reproductive performance. IUGR contributed to decreased DNMT-1, Bcl-2 and IGF-1 expressions, but up-regulated Bax and p53 gene expressions. Maternal folic acid supplementation reversed Bcl-2, p53 and DNMT-1 expressions. Collectively, maternal folic acid supplementation reversed IUGR altered kidney expression levels of genes related to one-carbon metabolism and apoptosis, thus providing a chance to rescue the phenotype of IUGR individuals with folic acid.

Key words: Folic acid; intrauterine growth restriction; gilts; gene expression, kidney