Fig. 1: Maternal diabetes suppresses FGF2 expression through DNA hypermethylation.

a, b Abundance of FGF2 mRNA (a) and protein (b) in E7.5 conceptuses. (c) The CpG island (the light green area) of the Fgf2 promoter in E7.5 conceptuses. d The degree of methylation in the CpG island of Fgf2 promoter determined by Methylation-specific PCR (MSP) along with non-methylated specific PCR (NSP). e Methylated C (cytosine) frequencies in the 64 CpG sites of the CpG island after cloning CpG islands from the Fgf2 promoter for bisulfite sequencing. DNA isolated from E7.5 embryos of three dams (n = 3) per group and DNA was cloned and sequenced twenty times per group. f Quantification of methylated cytosine from (e). g The methylation inhibitor RG108 restored Fgf2 promoter luciferase reporter activity suppressed by high glucose (25 mM glucose) in the yolk sac endoderm PYS2 cell line. Cells experiments were repeated three times (n = 3). Experiments were performed using three embryos from three different dam per group (n = 3). * indicates significant difference compared to other groups (P < 0.05). ND: nondiabetic; DM: diabetes mellitus.