Epigenetics is concerned with changing gene activity without changing the DNA sequence of the gene. Many processes in the body are based on the processes of epigenetics. Recent research demonstrates its importance in the ability of the organism to modify itself in the context of environmental influences.
What is epigenetics?
The term epigenetics refers to activity changes of genes in addition to heredity (genetics). The term epigenetics refers to activity changes of genes in addition to heredity (genetics). This therefore means that the genetic code of a gene is fixed, but does not always come into play. In this context, epigenetics deals with the changes in the genome function of DNA that do not result from a change in the DNA sequence. Thus, every cell of a living being contains the same genetic program. However, in the course of its development, organs and various tissues differentiate. For example, blood cells possess the same hereditary information as the cells of the kidneys. The only difference is that different genes are active in the two types of cells. The differentiation of cells can be explained by epigenetic processes, which are expressed by the activation or inactivation of genes. Undifferentiated cells are so-called stem cells, which can develop into a new genetically identical organism via cloning. However, differentiated cells can also be transformed back into stem cells by reversing the epigenetic change.
Function and task
Epigenesis progressively alters genetic information within the cell after each cell division. In this process, certain genes are inactivated by DNA methylation. Another way is by marking DNA through a process called histone acetylation. In this process, the two-meter-long DNA strand in the tiny cell nucleus is unpacked and marked at specific locations. This guarantees that only the information relevant to the corresponding cell type is read. Both methylation and histone acetylation are controlled by biochemical agents. Every organism, including humans, has many so-called epigrams. Epigrams are additional genetic codes that determine the modification of the organism. In the course of life, the organism changes more and more under the influence of the environment. The genetic code remains, but the external influences gain more and more importance. The environmental influences include nutrition, stress factors, social contacts, environmental toxins or even experiences made, which anchor themselves in the psyche of the human being. It is known that the body reacts to these factors and stores experiences in order to be able to react to them when necessary. According to recent findings, all interactions between the organism and the environment are controlled epigenetically. As a consequence, external appearance (the phenotype), character and behavior are significantly shaped by epigenetic processes. The different development of identical twins under different external influences shows how strong the imprinting can be. Another example may be physical changes due to the change of the sex lived out, which occur without the addition of drugs. The Albanian burrneshas (women who live the life of a man), among others, are testimony to this. Some researches prove that acquired traits can be further inherited. In this process, the basic genetic code is passed on, but additional genetic changes (epigenetic changes) are also partially passed on to the offspring, while maintaining the given DNA sequence of the genes.
Diseases and disorders
The influence of epigenetics on human phenotype and behavior is now becoming increasingly clear. In this regard, new research findings point to the importance of epigenetic processes on human health. For example, many diseases have a genetic preposition. They occur more frequently in families. Examples are diabetes mellitus, cardiovascular diseases, rheumatic diseases or dementia. Here, lifestyle plays a major role in whether the corresponding disease breaks out at all. In identical twins, for example, it was found that Alzheimer’s disease is very strongly dependent on the environment, despite the genetic predisposition. Epigenetics has also clarified why green tea, for example, is so healthy.The active ingredient epigallocatechin-3-gallate (EGCG) in tea activates a gene that encodes a cancer-preventing enzyme. In older people, this gene is often methylated and therefore inactive. This increases the likelihood of developing cancer in old age. However, by drinking green tea, the probability of cancer decreases again. In the realm of bees, on the other hand, the queen does not differ genetically from the workers, for example. However, since she is the only animal fed with royal jelly, she develops into a queen bee. In her case, many dumb genes are reactivated due to a certain biological agent. In humans, unfavorable social conditions, among other things, often lead to personality disorders later on. Today, it must be assumed that many psychological and mental illnesses are triggered by epigenetic processes. Traumas are therefore also stored in the human epigenome, which later have an influence on the personality structure. For example, new scientific research has shown that many errors are created in the genetic material of traumatized people. However, after successful therapy, these errors disappeared. There are also epigenetic changes that are inherited by the offspring and provide them with a genetic predisposition to certain diseases. In a Swedish human study, for example, the connection between food availability and predispositions to diseases in subsequent generations was investigated. Geneticists Marcus Pembrey and Lars Olov Bygren found that the male grandchildren of grandfathers who had plenty to eat were always prone to diabetes. Epigenetic changes probably took place here on the sex chromosomes. Traumatized people can also pass on epigenetic changes to subsequent generations. Further research in the field of epigenetics should help uncover and reverse disease-causing epigenetic changes.
