Are we what their parents ate?

2012/02/23 Carton Virto, Eider - Elhuyar Zientzia

• Biokimika
• Genetika

“It is often said that we eat, but we are also the ones who ate, drank and burned our parents.” Researcher Manel Esteller talks about the heritability of epigenetics. Is it possible to transmit to their descendants the epigenetic changes that an individual has suffered in his life, as we transmit the genes?Epigenetics studies the regulation of the genome, why people, animals and plants that have the same genes have different characteristics and diseases. Epigenetics includes the mechanisms that, without altering the sequence of DNA, but influencing the expression of the genes, cause the appearance of variants in the phenotype. The chemical marks are mainly two: in one of them a molecule is added in certain areas of the DNA sequence, silencing one gene; in the other, the reaction occurs in proteins that help to package the DNA, causing the expression of silenced genes Precisely, the difference between a liver cell and a neuron is that they have different epigenetic patterns and function differently. Women have one of the two X chromosomes completely silenced. Epigenetics is a common physiological mechanism, essential for the development, differentiation and functioning of cells. Each type of cell has an epigenetic pattern and each living has its own pattern as a member of a certain species. Not only that, this pattern is changing throughout the individual's life cycle. Our embryonic pattern is different from what we have in adolescence, and what we have in adulthood is different. Although in the end humans have a single genome, we have 150 epigenomes.Another characteristic of epigenoma is that it is much more sensitive than the genome with the medium. In addition, epigenetic changes are more numerous and faster than genetic changes. And since it does not have as much influence as genomes in survival, cells have not developed as many mechanisms to correct epigenetic defects. Finally, life habits and external factors such as smoking, physical activity, or diet can cause permanent epigenetic changes in the long term. Precisely, Esteller's team has discovered that genetically identical twins differ over time, the more different their lifestyle is: The question is immediate: if the permanent epigenetic changes produced by the medium occur in eggs and sperm, will they inherit them? Quick answer: we don't know. Some discoveries have already been made in favor of this option. Between plants and fungi there are well documented examples of transgenerational epigenetics. In mammals, on the other hand, the data are scarce and more doubtful: in the mouse and in the rats have supposedly observed the effects that pass from one generation to another by epigenetic mechanisms, but neither the first nor the second are very clear.In contrast to the heritability of the acquired characteristics, other two factors are, on the one hand, the high rate of failure in the mechanism of copying of the epigenetic marks, but rather unstable embrytic marks. In any case, this type of epigenetics quickly captures the imagination of people, at least mine. Many have seen there a possible mechanism to explain the influence of the medium on physiology and long-term behavior. For others, as indicated in the article Perceptions of epigenetics, published by researcher Adrian Bird in the journal Nature, “the fact that epigegenetic marks acquired in life are possible from parents to children has a lamarcco tone so attractive that it is difficult not to consider them as a possible antidote of genetic determinism.”

Published in the newspaper Berria.