blondbraintrust

A disease you are suffering today could be a result of your great-grandmother
being exposed to an environmental toxin during pregnancy.

Researchers at Washington State University reached that remarkable conclusion after finding that environmental toxins can alter the activity of an animal's genes in a way that is transmitted through at least four generations after the exposure. Their discovery suggests that toxins may play a role in heritable diseases that were previously thought to be caused solely by genetic mutations. It also hints at a role for environmental impacts during evolution.

Skinner and a team of WSU researchers exposed pregnant rats to environmental toxins during the period that the sex of their offspring was being determined. The compounds – vinclozolin, a fungicide commonly used in vineyards, and methoxychlor, a pesticide that replaced DDT – are known as endocrine disruptors, synthetic chemicals that interfere with the normal functioning of reproductive hormones.

The finding that an environmental toxin can permanently reprogram a heritable trait also may alter our concept of evolutionary biology. Traditional evolutionary theory maintains that the environment is primarily a backdrop on which selection takes place, and that differences between individuals arise from random mutations in the DNA. The work by Skinner and his group raises the possibility that environmental factors may play a much larger role in evolution than has been realized before. This research was supported in part by a grant to Skinner from the U.S. Environmental Protection Agency's STAR Program.

# posted by blondbraintrust @ 11:09 AM