Keep an eye on the genes
Our genes are affected by the environment we live in and our lifestyles. All through certain chemical groups that can attach themselves to DNA. They determine the appearance of various diseases, including cancer, and also cause monozygotic twins to become increasingly different from each other over time.
Scientists have long believed that genes determine everything. Once we inherit them, the environment will not change them and we will stay with them until we die. A dozen years ago, however, it turned out that this is not the case — under the influence of environmental factors, genes can be switched on and off. The mechanisms responsible for this phenomenon were called epigenetic (the term means “above the genes”, the prefix epi comes from the Greek). Turning off a gene is another way to stop the synthesis of the protein it encodes. Usually, the activity (expression) of genes is inhibited by small chemical groups called methyl groups, which attach to specific DNA sites (mainly to cytosine), and the whole process is called methylation. Demethylation (removal of methyl groups) usually turns genes back on, which means that protein synthesis is triggered. There is no change in the composition of DNA here — all its “bricks” (nucleotides) remain the same.
