The more experienced will probably have noticed this information,"First Epigenome in Europe Completed" according to which the full epigenome has been described. Certainly, as often in biology, this mainly concerns pathological conditions and studies on more complete cases will take time, but this article"Our diet would affect the DNA of our grandchildren", more general public and therefore more popularizer, specifies things. If we refer to older examples, we must expect paradigm shifts.
As a reminder, epigenetics (epi, outside, and genetics) is the field that studies how the environment and individual history influence gene expression, and more precisely the set of changes, transmissible from one generation to the next and reversible, of gene expression without alteration of nucleotide sequences (of DNA itself). The existence of these phenomena governing gene expression can be summed up in Thomas Morgan's initial question:"…. If an individual's traits are determined by genes, why are not all cells in an organism the same? ".
More strikingly, we can recall that a caterpillar and its butterfly have exactly the same genes. In the course of development, therefore, programming through epigenetic processes could be added to the genetic heritage, itself under the influence of a multitude of environmental factors, themselves having an impact at the cellular level. Another example is the set of differences between identical twins: their genome is identical, but if they live in different environments, the expression of it will differ.
The epigenome is therefore the epigenetic state of the cell. Like embryonic cells which can have several final functions, a single genome can be modified in multiple ways to give different epigenomes, resulting in the formation of …
