After reviewing the literature, she has found more than 100 examples of living organisms, from bacteria to human beings, demonstrating how our genes' expression can be altered and inherited.
"Stress is enormously important," Prof. Jablonka says. "It can affect the development of cancer and other chronic diseases, and may also have long term impacts on ecology." At the conclusion of the Human Genome Project, researchers hoped that the findings would provide relief from several diseases. "What they weren't prepared for," she continues, "is that genes really do so many things, and that gene expression patterns can be heritable. We can learn some things about diseases from our DNA, but it doesn't tell the whole story."
Is environmental pollution irreversible?
Stress can create near invisible effects on gene expression, effects that can be passed from mother or father to child. Some of this operates through microRNA, tiny RNA discovered about a decade ago which work as cellular "micro-managers." In addition, a process called DNA methylation alters gene function. Various processes "hidden" in chromosomes within the cells appear to be influenced by lifestyle and disease.
As a result, Prof. Jablonka advises that it might be prudent to reconsider all the environmental pollutants being introduced into the planet's ecosystems. Some pesticides and fungicides are androgen suppressors and have many effects on gene expression and these effects can be inherited. Whether and how future generations can endure with these altered gene functions are still open questions, she says.
|Contact: George Hunka|
American Friends of Tel Aviv University