DNA methylation-dependent induction of silencing. (A) Example of the time-dependent deposition and loss of DNA methylation analyzed by bisulfite sequencing. Each row indicates one sequenced clone and each column indicates one CpG site. The blue and red colors display unmethylated and methylated CpGs, respectively. (B) Quantification of DNA methylation over time. The averages and SEM refer to the data sets shown in Additional file 1: Figure S2. (C) Methylation level ranking based on the data sets shown in Additional file 1: Figure S2. (D) Quantification of VEGF-A expression normalized to SDHA. The averages and SEM are based on two to three biological repeats. VEGF-A, vascular endothelial growth factor A.