Thursday, November 18, 2010

How life experiences alter what our genes do.

It has been a frustration that we are unable to pinpoint causative genetic effects in many complex diseases and behavioral abnormalities. Many think the missing information resides in our nongenetic cellular memory, which records developmental and environmental cues. "Epigenetics" has become the catch-all phrase for many environmentally influenced genetic regulatory systems involving DNA methylation, histone modification, nucleosome location, or noncoding RNA. The basic requirement for an epigenetic system is that it be heritable, self-perpetuating, and reversible. Benedict Carey has done a nice non-technical article on epigenetics, how people’s experience and environment affect the function of their genes. Some clips:
Genes are far more than protein machines, pumping out their product like a popcorn maker. Many carry what are, in effect, chemical attachments: compounds acting on the DNA molecule that regulate when, where or how much protein is made, without altering the recipe itself. Studies suggest that such add-on, or epigenetic, markers develop as an animal adapts to its environment, whether in the womb or out in the world — and the markers can profoundly affect behavior.

...researchers have shown that affectionate mothering alters the expression of genes, allowing them to dampen their physiological response to stress. These biological buffers are then passed on to the next generation: rodents and nonhuman primates biologically primed to handle stress tend to be more nurturing to their own offspring.

...Epigenetic markers may likewise hinder normal development: the offspring of parents who experience famine are at heightened risk for developing schizophrenia, some research suggests — perhaps because of the chemical signatures on the genes that parents pass on. Another recent study found evidence that, in some people with autism, epigenetic markers had silenced the gene which makes the receptor for the hormone oxytocin. Oxytocin oils the brain’s social circuits, and is critical in cementing relationships.

...The National Institutes of Health is sponsoring about 100 studies looking at the relationship between epigenetic markers and behavior problems, including drug abuse, post-traumatic stress, bipolar disorder and schizophrenia, compared with just a handful of such studies a decade ago.

3 comments:

  1. May I refer you to Dr. Ernest Rossi's works about the genetic expression of psychotherapeutic change? It is a pleasure to read you. Thank you very much

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  2. My cousin, who has a master's in chemistry from Georgetown, has decided that epigenetics means that she can modify her genes *now* and thus defeat her breast cancer. She had psychic surgery in Brazil and is now living in Peru with a tribe which is furthering her "treatment" using native medicine. Her decision is an example of how scientific discoveries are co-opted by believers. I expect to hear in the next few months that she has died, painfully, from the cancer.

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  3. Nice post!Epigenetics is an interesting subject wherein you study the reactions and factors of chemical reactions that switch parts of the genome off and on.Research reveals some of the shocking results of genetic modification.
    Dr.Batras

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