Underfeeding a pregnant mouse can cause changes in the sperm of her male offspring, possibly affecting the health of her grandchildren, a new study published July 10 in the journal Science has found.
The changes appear to be epigenetic, a term that describes how methyl groups and other molecular tags attach to genes, influencing their expression. The field of epigenetics describes how experience and environment affects the function of genes.
The team, led by geneticist Anne Ferguson-Smith of the University of Cambridge and diabetes researcher Mary-Elizabeth Patti of Harvard Medical School, cut the calories of mouse food in half during the last week of gestation and then studied two generations of mice descending from the malnourished mother.
This study offers “some of the strongest evidence yet” that a mother’s environment during pregnancy can change the DNA in ways that can be passed on to her offspring. And it adds to a body of evidence suggesting that environmental stress to the parent can affect the health of future generations.
But while “fetal tissues from the mother mouse’s grandchildren also had similar changes in gene expression, surprisingly, the DNA in these tissues did not carry these methylation differences,” Science reports. “That suggests that the changes eventually disappear.”
The Science story quotes epigenetics researcher Oliver Rando of the University of Massachusetts Medical School in Worcester who called it a “nice study,” but added, “I wouldn’t say the book is closed on how these things work.”