Archives for the day of: October 29, 2010

From All Things Considered (portions of a radio news story discussing a recent Nature article challenging the conventional wisdom about genetic inheritance):

We can’t change the genes we received from our parents. But our genes are controlled by a kind of instruction manual made up of billions of chemical markers on our DNA, and those instructions can be rewritten by our circumstances — for instance, by obesity. According to the new research, they can even be passed along to children.

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The Grammar Of DNA

[Andy] Feinberg thinks he knows how this may be happening. It’s an example of an “epigenetic” effect, which is his specialty.

This field — epigenetics — is getting a lot of attention these days. It refers to things in and around our DNA, such as billions of chemical markers that attach to it. Those markers are signals that turn genes on and off. They tell the genes of a liver cell to behave differently from genes in a blood cell, for instance.

The sequence of our DNA — the human genome — has been called the book of life. Feinberg has his own metaphor for the billions of added signals that he studies. If the genetic sequence is the words of the book, the epigenome is the grammar, he says. “It helps to tell what the genes are actually supposed to do, and puts them in context.”

Our genes don’t change, or if they do, it’s a rare and random event. But the grammar of the epigenome is changing all the time. It can also be disrupted by chemicals we eat or breathe.

Apparently it can also be disrupted by obesity, because Feinberg thinks those fat dad rats in Australia created sperm cells with a different pattern of epigenetic marks on their DNA; that’s how the effect showed up in their children.

Michael Skinner at Washington State University in Pullman says epigenetic effects are swinging the pendulum of scientific attention from the genetic code back toward the impact of environment.

“I think that we’re eventually going to have sort of a merger of this,” he says. “I think that we’re going to have an appreciation of the fact that there is an environmental influence on biology that probably through more epigenetic mechanisms. There’s also a baseline genetic element of biology. And the two combined will actually give us more information about how things work.”

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The entire story, the podcast, and related links can all be found here.

Bloomberg News: Flooring, wallpaper emit toxic chemicals, group says in urging regulation.

U.S. homes may contain flooring and wallpaper that emit the types of toxic chemicals the Consumer Product Safety Commission has banned from toys, an environmental group said in urging expanded regulation of the substances. The building materials may expose kids to chemicals such as phthalates that were banned in children’s products in a 2008 overhaul of the CPSC, said Jeff Gearhart, research director at the Ecology Center in Ann Arbor, Michigan, which today released a study showing emissions from 3,000 products. Lead and cadmium also were found in some products, he said. “Toys aren’t the only source of exposure,” Gearhart said in an interview. “We really need a broader federal policy reform. We should be looking at chemicals in everything, not product by product.” Read more here.

Postmedia News: Feds should ban ‘dirty dozen’ chemicals: report.

Looking primped and polished can be hazardous to your health, according to a new report by the David Suzuki Foundation that’s calling on the government to do more to keep a “dirty dozen” toxic chemicals out of personal care products sold in Canada. The study looked at ingredient labels on more than 12,500 products ranging from makeup and lotions to deodorants and toothpaste. It found some 80 per cent of products contained at least one of 12 chemicals or groups of chemicals on a shortlist of common cosmetic ingredients deemed harmful to the environment and human health. Read more here.

Toronto Star: Canadian mining firms worst for environment, rights.

Canadian mining companies are far and away the worst offenders in environmental, human rights and other abuses around the world, according to a global study commissioned by an industry association but never made public.“Canadian companies have been the most significant group involved in unfortunate incidents in the developing world,” the report obtained by the Toronto Star concludes. . . . The problems involving Canada’s mining and exploration corporations go far beyond workplace issues. “Canadian companies are more likely to be engaged in community conflict, environmental and unethical behaviour, and are less likely to be involved in incidents related to occupational concerns.” Read more here.

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