Real Talk!

04/28/07 I wrote a blog enitled “OF DNA FOSSIL FUEL AND MEMORY” which made a segue into a somewhat philosophical spew about genetics and genetic memory… and inherited memories and…

anyway… a friend recently mentioned epigentics to me. And you know what that means… I have been researching it, furiously, in my spare time.

Essentially, epigentics is a branch of science that has, more intensely since the 80s, been working on a theory that there is some sort of “on-off switch” with a molecular basis through which heritable information other than DNA sequence influences gene function.

The commonly accepted notion is that through our DNA we are destined to have particular body shapes, personalities, and diseases and perhaps even a predetermined intelligence and predilection to certain social ills, including poverty, crime, and violence.

We know that certain biological ‘information’ is passed from parents to their offspring and that cells pass information on to each other, when they divide and it seems that it’s not just the genes that influence the traits and functions. of an organism but also ‘epigenetic’ or non-gene factors.

There are “epigenetic” factors within the cell that can be inherited when cells divide without changing the genes themselves. They do, however, modify the behaviour of genes.

Epigenetics researchers have recognized there are many molecular sequences and patterns that may determine which genes can be turned on and off. Studies indicate that the introduction of some vitamin, or brief exposure to a toxin, even an added dose of mothering can tweak the epigenome—altering the software of our genes, if you will—in ways that affect an individual's body and brain for life.

Perhaps even more unbelievable, epigenetic signals from the environment can be passed on from one generation to the next, sometimes for several generations, without changing a single gene sequence.

Okay, we’ve all been taught that environmental effects like radiation, can alter the genetic sequences in a sex cell's DNA and can leave a mark on subsequent generations. It's well documented that the environment in a mother's womb can alter the development of a fetus. What is really interesting it the growing evidence that the epigenetic changes brought on by diet, behaviour, or surroundings can work their way into the line up and resonate far into the future.

It seems that what we inherit from our parents are chromosomes, and chromosomes are only 50 percent DNA. The other 50 percent is made up of protein molecules, and it’s these proteins that carry epigenetic marks and information.

Over the years, researchers have argued on one side or the other, or a combination of both in the nature-versus-nurture divide. Recently, scientists have found solid proof that nurturing attention from the mother stimulates serotonin receptors in the hippocampus of her child. These receptors send proteins called transcription factors to turn on the gene that inhibits stress responses. This switch can alter gene expression permanently.

It is interesting to note that adults who reported in a questionnaire that they had a poor relationship with their mother were found to have hippocampi that were significantly smaller than average. Those adults who reported having had a close relationship with their mother, however, showed normal size hippocampi.

In November 2005, a clinical geneticist presented data drawn from two centuries of records on crop yields and food prices in an isolated town in northern Sweden. Swedish researchers have discovered that fluctuations in the towns' food supply may have health effects spanning at least two generations.

Grandfathers who lived their preteen years during times of plenty were more likely to have grandsons with diabetes—an ailment that doubled the grandsons' risk of early death. Equally notable was that the effects were sex specific. A grandfather's access to a plentiful food supply affected the mortality rates of his grandsons only, not those of his granddaughters, and a paternal grandmother's experience of feast affected the mortality rates of her granddaughters, not her grandsons.

It appears that timing is critical to the intergenerational impact. There was a direct corelation to the ages at which grandmothers and grandfathers experienced a food surplus and the affect on future generations. The granddaughters most affected were those whose grandmothers experienced times of plenty while in utero or as infants, precisely the time when the grandmothers' eggs were forming. The grandsons most affected were those whose grandfathers experienced plenitude during the so-called slow growth period, just before adolescence, which is a key stage for the development of sperm.

I guess it means that our environment and general health (emotional as well as physical) has an affect on the way our bodies manufacture the protein with which our cellular information is packaged. So it stands to reason that if it’s packed differently- even identical strands of information would be open to a slightly different interpretation.

The logic of all of this applies backward as well as forward: Some of the disease patterns prevalent today may have deep epigenetic roots. If you have a generation of poor people who suffer from bad nutrition, it may take two or three generations for that population to recover from that hardship and reach its full potential.

To put all of this into simple terms what you eat or smoke today could affect the health and behavior of your great-grandchildren and in more ways than you might suspect.

& apparently, our cells do have some pretty serious memory capacity.