sptlt207There are times in life when things are best left unsaid. So you bite your tongue or someone bites it for you. Either way, you are silenced and no - or less - harm is done. Nature also has its techniques for muffling genes whose products are not necessary at a given time, or that are perhaps harmful once expressed. One technique, which seems to have been with us for a very long time, is DNA methylation. DNA methylation is like locking a door with a key that you promptly throw away: you're making things difficult for someone to open it and see what's on the other side. In the same vein, DNA methylation has the capacity to keep a gene in a locked - or silent - state, thus hindering the production of an undesirable protein and a probable adverse downstream metabolic pathway. DNA methyltransferase 3C is one of the many enzymes able to gag a gene. Although not any old gene: DNA methyltransferase 3C seems to silence specifically retrotransposons. Read more