Stressed Out Genes

A new study in Cell is helping to clarify how the stress of starvation or drug addiction can be passed on to subsequent generations through epigenetic changes, reports New Scientist's Andy Coghlan. Previous studies have already shown that if mice are stressed after birth, their offspring can be born with signs of depression or anxiety. This new study identifies a molecular mechanism by which the effects of that stress can be handed down without alteration of the genes or DNA, Coghlan says. "[The research] team have shown that chemical or environmental stress detaches a protein called activating transcription factor 2 from chromatin, the densely packed DNA that makes up chromosomes," Coghlan writes. "ATF-2 serves as a kind of zipper, keeping the chromatin tightly bound. Once it is detached, the chromatin structure physically opens up, enabling otherwise hidden genes to become active." The unzipped chromatin is inherited by all descendants of the original cell, he adds.