Friday, February 27, 2009

mystical epigenetic materialism...,

Think Gene | Epigenetics is the study of changes in the function of genes that don’t involve changes in the sequences of DNA. The DNA is inherited from our parents; it remains fixed throughout life and is identical in every part of the body. During gestation, however, the genes in our DNA are marked by a chemical coating called DNA methylation. These marks are somewhat sensitive to one’s environment, especially early in life.

The epigenetic marks punctuate the DNA and program it to express the right genes at the appropriate time and place.

A team of McGill University scientists has discovered important differences between the brains of suicide victims and so-called normal brains. Although the genetic sequence was identical in the suicide and non-suicide brains, there were differences in their epigenetic marking – a chemical coating influenced by environmental factors.

All of the 13 suicide victims in the study had experienced abuse as children.

“It’s possible the changes in epigenetic markers were caused by the exposure to childhood abuse, although in humans it’s difficult to establish causality between early childhood and epigenetic markers, in the way we have established this in animal subjects,” said Moshe Szyf, a professor in McGill’s Department of Pharmacology and Therapeutics.

“The big remaining questions are whether scientists could detect similar changes in blood DNA – which could lead to diagnostic tests – and whether we could design interventions to erase these differences in epigenetic markings”