We used to think that once a cell reaches full maturation, its DNA is totally stable, including the molecular tags attached to it to control its genes and maintain the cell’s identity. Some cells actually alter their DNA all the time, just to perform everyday functions
2021-08-30: DNA breaks for memory consolidation
When the team mapped genes undergoing double-strand breaks in the prefrontal cortex and hippocampus of mice that had been shocked, they found breaks occurring near 100s of genes, many of which were involved in synaptic processes related to memory. DNA breakage might be a regulatory mechanism in many other cell types. But even if breaking DNA is a particularly fast way to induce crucial gene expression, whether for memory consolidation or for other cellular functions, it’s also risky. If the double-strand breaks occur at the same locations over and over again and aren’t properly repaired, genetic information could be lost. Moreover, “this type of gene regulation could render neurons vulnerable to genomic lesions, especially during aging and under neurotoxic conditions. It is interesting that it’s used so intensively in the brain, and that the cells can get away with it without incurring damage that’s devastating.”