Welcome news from ScienceDaily (June 24, 2011), for people who are fed up with Genes Rule contending with Environment Rules:
Effects of Stress Can Be Inherited, and Here's How
"There has been a big discussion about whether the stress effect can be transmitted to the next generation without DNA sequence change," said Shunsuke Ishii of RIKEN Tsukuba Institute. "Many people were doubtful about such phenomena because the mechanism was unknown. Our finding has now demonstrated that such phenomena really can occur." Ishii and his colleagues now confirm that ATF-2 is required for heterochromatin assembly in multicellular organisms. When fruitflies are exposed to stressful conditions, the ATF-2 is modified and disrupts heterochromatin, releasing genes from their usual silenced state. Importantly, these changes in genomic structure are passed on from one generation to the next.
The researchers expect that this finding in flies has relevance for humans, noting that we also carry the ATF-2 gene. Those epigenetic changes may influence basic cellular functions as well as metabolism, behavior and disease. In particular, Ishii suggests that epigenetic causes may play a role in "lifestyle diseases," including heart disease and diabetes, and in psychological diseases, such as schizophrenia.
So in a number of critical situations, environment helps determine which genes rule.
Not that popular culture will get the picture any time soon, but
sources say that epigenetics points to resolving some intractable social disputes.
Too familiar scenario: We are told, "it's in the genes" for [a given ethnic group] to have a high rate of diabetes, high blood pressure, or whatever. Members of the group reply angrily that, if only people recognized the stress they are under … Turns out both are right, which means looking for practical solutions got a lot easier.
For example, a nurse can advise a patient, "Because – based on your family history – this lifestyle factor could be a higher stress for you than for a statistical sample of the public, pulled off the street, … it's suggested that you avoid it," without risking legitimate accusations of stereotyping. We're not saying it's "in your genes because you're an X ", thus promoting defensiveness and denial. It's not "in her genes," it's a known, avoidable risk. It's up to the patient to take the advice, but now we have something science-based to tell her.
Goodbye, Gene War, and let the door smack you one hard in the face on the way out.
Here Any Coghlan offers New Scientist's take: "Unzipped chromosomes pass on parental stress" (27 June 2011)
Stress is thought to cause "epigenetic" changes that do not alter the sequence of DNA but leave chemical marks on genes that dictate how active they are. Previous studies have shown that if mice are stressed for two weeks after birth, their offspring will show signs of depression and anxiety, despite enjoying the usual levels of maternal care. And there is mounting evidence that common health problems including diabetes, obesity, mental illness and even fear could be the result of stress on parents and grandparents.
Denyse O'Leary is co-author of The Spiritual Brain.