Figure 2

Methylation dynamics of the IGF2-H19 gene cluster. Methylation of the CpG regulatory box CTCF3 region for IGF2-H19 gene cluster was investigated by bisulfite sequencing. A DNA pool from germ cells of 6-8 embryos of each gender in the stages E22, E25, E29-31 and E42 was bisulphite converted and used for the analysis after one PCR reaction and subsequent transformation and cloning. The position of the CTCF3 is indicated on the schematic representation of the gene cluster and the sequence of the investigated fragment after bisulfite mutagenesis is showed below. Empty and filled circles indicate unmethylated and methylated CpGs, respectively. 12-18 clones were analysed from each group. Each horizontal line represents one clone. Percent methylation mean ± SEM for each group is indicated below.