Figure 7.

PCNA-binding-deficient mutant Dnmt1 restores methylation of single-copy sequences in dnmt1^−/− ES cells. Mouse dnmt1^−/− ES cells were transiently transfected with either the GFP-Dnmt1^wt or GFP-Dnmt1^Q162E constructs and FACS-sorted 24h and 48 h after transfection. Methylation of single-copy sequences was assayed by COBRA. Shown are methylation percentages at assayed CpG sites with respect to genomic DNA from dnmt1^−/− ES cells methylated in vitro with the recombinant methyltransferase SssI (100% methylation; see also Supplementary Figure 6). Mean values and standard errors of duplicate amplifications from each of two independent experiments are indicated.