The Epigenetics Challenge | Childhood Obesity News
The whole field known as epigenetics is like a wild and wooly frontier. A Harvard University publication calls it an emerging area of research. Basically,
[…] the DNA that make up our genes accumulates chemical marks that determine how much or little of the genes is expressed… The different experiences children have rearrange those chemical marks…
Which explains the mystery of why identical twins can have quite diverse skills and personalities, and different levels of health and achievement. One consequence of this malleability is that arguing “Nature versus Nurture” is a waste of breath. The parental genes a person receives are not the final word on anything, and because developmental experiences “rearrange the epigenetic marks that govern gene expression, they can change whether and how genes release the information they carry.”
A child’s early experiences alter gene expression and affect long-term development whether we like it or not, and whether or not we believe it. Events and circumstances can influence how easily a gene may be switched off or on, and may leave a temporary or permanent mark. To express the concept in a more colloquial way, pretty much everything is up for grabs.
Outcomes depend on such variables as learning opportunities, supportive or destructive family relationships, and the general stressfulness of the surroundings, which may be anything from an odious intellectual environment of stultifying boredom to a catastrophic war zone:
The “biological memories” associated with these epigenetic changes can affect multiple organ systems and increase the risk not only for poor physical and mental health outcomes but also for impairments in future learning capacity and behavior.
The realization that nothing is “set in stone” can be crushing or exhilarating, and the exciting challenge of working with the concept that change may be just within our reach surely fuels the souls of many scientists.
It gets crazier
Things really changed in this area of knowledge with such events as wartime famine in the Netherlands which indicated the possibility of traits that were not genetic, yet nevertheless were heritable. A study showed that men who were still in the womb when their mothers experienced malnutrition tended to have children with a tendency to become overweight adults.
Just when everything already seems complicated enough, the pipeline delivers more baffling information. According to a brand new Northwestern University/University of Texas report, explained by its originators in advance of official publication, “Temporary stress can cause heritable changes without altering the genetics…”
What now? Some of us have just become used to a packet of new ideas about how things work, and already we have to revise them? What exactly is going on here anyway? Well, it seems that…
Bacterial cells can “remember” brief, temporary changes to their bodies and immediate surroundings… And, although these changes are not encoded in the cell’s genetics, the cell still passes memories of them to its offspring — for multiple generations.
Human have entertained a lot of notions about how simple little bacteria inherit and pass along their physical characteristics, and it now appears that this understanding was incomplete. The need for revisionist thinking began to be suspected as far back as 2001, with the Human Genome Project.
Adilson Motter, the new study’s senior author, explained to interviewers that among bacterial biologists, it has long been assumed that DNA is the chief determiner of physical characteristics. However, as it turns out, “information also can be stored at the level of the network of regulatory relationships among genes.”
Scientists wondered whether characteristics can be transmitted from one generation of bacteria to the next by some means other than DNA encoding. Could the cause be the regulatory network itself? Because “the echoes of changes affecting their parents persist in the regulatory network while the DNA remains unchanged.”
Genes interact not only with each other, but with elements of the environment like temperature, available nutrients, and acidity. Excitement is in the air, for it appears that a lot of big discoveries are on the horizon:
For example, researchers could circumvent antibiotic resistance by subtly tweaking a pathogenic bacterium to render its offspring more sensitive to treatment for generations. Image the repercussions of harnessing that sort of knowledge.
Your responses and feedback are welcome!
Source: “What is Epigenetics?,” Harvard.edu, undated
Source: “Bacterial cells transmit memories to offspring,” ScienceDaily.com, 08/29/24
Image by Bernd Thaller/Attribution 2.0 Generic
