Stress in fruitflies can cause changes in gene expression that are passed on to subsequent generations.

A group led by Shunsuke Ishii at the RIKEN Tsukuba Institute in Japan studied the protein ATF2 in Drosophila. They found that this protein is needed for the formation of heterochromatin — tightly packed DNA–protein complexes that block the expression of certain genes. Stress causes phosphorylation of ATF2, dislodging it from heterochromatin. When Drosophila embryos were exposed to heat shock during development, the resulting flies expressed certain genes that are normally silenced by heterochromatin, such as a gene for red eye colour.

The errant heterochromatin packaging and red eye colour were also seen in offspring of males that had been exposed to heat stress during development.

Cell 145, 1049–1061 (2011)