For the first time, genes chemically silenced by stress during life have been shown to remain silenced in eggs and sperm, possibly allowing the effect to be passed down to the next generation.
The finding, obtained from detailed DNA scans in developing mouse eggs and sperm, backs up mounting indirect evidence that the genetic impacts of environmental factors such as smoking, diet, stressful childhoods, famine and psychiatric disease can be passed down to future generations through a process called epigenetic inheritance.
Many geneticists had considered this an impossibility.