Fig. 2

DNA methylation status of the del-8, 7, and 6 fragments in YAC TgM. a Map of the transgene fragments. Region differences (118 bp) among three constructs are shown in gray. Regions I and II that were analyzed by bisulfite sequencing in b and c were indicated by gray bars above the map. b Tail genomic DNAs of TgM inheriting the transgenes either paternally (pat.) or maternally (mat.) were pooled according to the transgene’s parental origin and subjected to bisulfite sequencing, the methylation levels of which were determined beforehand by Southern blotting in Additional file 2: Fig. S2. Each horizontal row represents a single DNA template molecule. Methylated and unmethylated CpG motifs are shown as filled and open circles, respectively. Position of CTCF-binding sites is shown by filled boxes. c Two-cell embryos that inherited the transgenes either paternally (pat.) or maternally (mat.) were embedded in agarose beads and treated with sodium bisulfite. The beads were used to amplify the region II in a by nested PCR. PCR products were individually subcloned and sequenced. The results from single beads are presented together in a cluster