FIG. 4.

Expression of Dnmt3a and Dnmt3b proteins in 7aabb cells fails to restore maternal methylation imprints. The same DNA samples described in Fig. 3 were digested with SacI and HhaI (A), BamHI and HpaII (B), PvuII and HpaII (C and D), or XbaI and HhaI (E) and hybridized to probes corresponding to the 5′ upstream region of H19 (A), the DMR2 of Igf2 (B), region 2 of Igf2r (C), the DMR of Peg1 (D), or the DMR1 of Snrpn (E). As controls, DNA from J1 cells was digested with the corresponding enzymes without HhaI or HpaII. The fragments derived from the paternal (p) and maternal (m) alleles are indicated.