"Each person has a single genome, but the epigenomes, about 150. One for each cell type." These are the words of Manel Esteller, the researcher who has participated in the report we have prepared with epigenetics in this issue. Esteller researches the epigenetics of cancer and his work is an example of the evolution of the area of epigenetics.
Without altering the DNA sequence, but influencing gene expression, epigenetics collects the mechanisms that cause variants to appear in the phenotype. The concept arises from embryology in the 1930s, by Conrad Waddington, to explain how gene regulation modulates development. In embryology, epigenetics describes what biochemistry does to create, from a single cell and genome, all types of cells and organisms; a person and their 150 epigenomes in our case.
Although the world of epigenetics is limited to embryology, it is fascinating, but the influence of epigenetics does not end at birth, and so is understood today this field of research, which encompasses the processes of regulation of genes that occur throughout the individual's life cycle, and in which Esteller's lines of research and similar have come through this expansion. In fact, epigenetic changes that occur in cells can cause diseases such as cancer. Or, because of different epigenetic marks, two people with the same genetic predisposition to cancer may evolve differently from disease. Although I have not said so far, one of the main signs of identity of the epigenome is exposure to the environment.
Precisely its sensitivity to the medium has made a direct call to our imagination and gradually opens a door that genetics had supposedly closed. If the environment and the habits of life influence and leave a mark on the epigenetic characteristics, is it possible to transmit to the descendants the epigenetic changes that occurred in an individual? Is it possible that the traces of the life of our parents or grandparents are hidden in our cells?