Can genes be regulated and reactivated?
"We have now shown in mouse embryonic stem cells that there is another mode of demethylation that avoids any break in the continuity of the DNA strand," Carell says. In this pathway, the attached methyl group is enzymatically oxidized to give rise to 5-formylcytidine, which Carell's team first detected in mouse stem cells in 2011. They have now used stable isotopes to label 5-formylcytidine in stem cells and shown that it is rapidly converted unmethylated cytidine. "This mechanism thus allows cells to regulate gene activity at the DNA level without running the risk that the DNA may be damaged in the process," Carell explains. The authors of the new study believe that this pathway could also be of medical interest, as it may provide a way to reprogram stem cells in a targeted fashion. Such a method would in turn open up new perspectives in regenerative medicine.
292 day(s) ago