Skip to main content
. Author manuscript; available in PMC: 2009 Jul 2.
Published in final edited form as: J Mol Biol. 2008 Feb 29;379(3):492–504. doi: 10.1016/j.jmb.2008.02.049

Figure 4.

Figure 4

Treatment of nuclear extracts with RNase A leads to random cleavage of the T·GmC ODN. (a) Diagram depicting an experimental protocol devised to examine methylation of repaired T·GmC ODN in normal and Dnmt null ES cell lines. Following repair of the T·GmC ODN using RNase A-treated ES cell nuclear extracts, the ODN was purified and heat denatured. It was then annealed to a 5-fold excess of cold antisense CG strand. This will generate an unmethylated or hemimethylated ODN depending on the methylation status of the repaired cytosine. MspI will digest either ODN but HpaII digestion will be inhibited if the repaired cytosine is methylated. (b) Results of the experiment diagrammed in (a). The T·GmC ODN appears to be degraded by each RNase-treated nuclear extract in a consistent pattern irrespective of methyltransferase expression. As a control, the C·GC ODN was incubated with RNase-treated J1 nuclear extract. The expected 26 nt digestion product is indicated by an arrow.