Early impressions of the child are directly related to the behavior of his mother, and this influence is much deeper than all of us think about it. This conclusion was made by scientists representing the Salk Institute.
First of all, Dr. Tracy Bedrosyan together with other scientists began to study the relationship between the stressful situation and the state of retrotransposons. Transposons are original sequences in DNA, capable of self-copying: sometimes they are called mobile gene components, or "jumping DNA." Transposons are diverse and differ in the copying scheme. Retrotransposons are one of such numerous options.
Transposon does not affect the state of the cell structure during self-copying to those parts of DNA that do not participate in the encoding. However, its penetration into the encoding can lead to a disruption in the work of the gene, as well as to multiple problems in the cell.
Previously, it was assumed that the state of transposons and their active "jumping" depends on the presence of stress: there was evidence that the stress of the mother influences the activity of transposons of children who are at the stage of intrauterine development. There were such experiments: pregnant female rodents were placed in different cages - either in uncomfortable and half-empty, or in light and comfortable. Scientists have noticed that the transposons in rodents really began to differ: in the first group the genome contained more copies of L1, and in the second - less. But it turned out that the state of the sequences is affected not only by the stress of the future mother.
The specialists continued their observations and noticed: the state depended on the way the female took care of newborn babies. When my mother carefully scrubbed and licked the young, did not leave for a second, the children in the hippocampus showed fewer copies of transposons - compared to those who were deprived of maternal care. The genome of the young, deprived of mother's affection, had an interesting feature: that DNA zone in front of the L1 transposon (with which the RNA-synthesizing proteins must be linked) was readily available.
As a rule, the cells disconnect transposons, as a result of which the gene is immersed in sleep. Since the cubs of poorly cared for rodents were deficient in the methylating enzyme, epigenetic surveillance worsened and the gene "woke up."
Researchers believe that the reason for this phenomenon is the tactile sensation. When a female licks and strokes her child, the skin signals and transmits impulses at the molecular level.
Further, scientists should answer numerous questions: in what will this change manifest, will it affect the development of the young, will affect their behavior?
We will wait for the results of new research.
More details about the experiment can be found in the article Science (http://science.sciencemag.org/content/359/6382/1395).