The effects of childhood violence may be passed down to the following generations by alterations in sperm, the Economist reports.
A Tufts University School of Medicine-led team sought to examine whether there are microRNA alterations within the sperm of men exposed to early violence. As they reported in Translational Psychiatry this week, Tuft's Larry Feig and his colleagues asked 28 Caucasian men about any childhood violence they experienced using a standardized questionnaire. The researchers then compared their scores to miRNA levels within sperm samples from the men. They found an inverse relationship between levels of miRNAs belonging to the miR-449/34 family and the men's scores.
The researchers reported a similar effect in male mice that experienced stress by being moved frequently to a new cage. Further, this effect was passed on to their offspring. As embryos, the researchers found that the mouse offspring, which exhibited more anxious behavior than usual, also had lower miRNA levels, as did the sperm of the male offspring upon maturity.
The Economist notes that the researchers haven't found that the miRNA causes this stress, but that it is suggestive and that Feig and his colleagues are planning additional studies.