Figure 2.

Dnmt cDNA is efficiently expressed from carboxyl-terminal truncated constructs. (Upper) pMT42, made by inserting a stop-codon containing linker into the NsiI site in pMT40 871 bp downstream of the initial ATG. (Lower) Northern blot analysis of Dnmt expression in Dnmt^s/s lines transfected with pMT42. Four of eight of the examined transfectants (lanes 5–12) showed an expression level approximately 50% that of the wild-type cells. The following lines are shown for comparison: wild-type J1 (lane 1), Dnmt^s/+ (lane 2), Dnmt^s/s (lane 3), and D23 (lane 4), a pMT40-transfected Dnmt^s/s cell line showing slight levels of Dnmt cDNA expression and genomic remethylation. The Dnmt cDNA was used as a probe. At the bottom is shown the same blot rehybridized with an α-tubulin cDNA to control for amount of RNA loaded. S allele-specific bands are as described in Fig. 1B.