You are what your mother ate, to some extent; how much depends partly on whether you are a boy or a girl, new research shows.
A study in mice reveals that expectant mothers’ diets influence gene activity differently in the placentas of male and female offspring, researchers report online March 8 in the Proceedings of the National Academy of Sciences. The placentas of female fetuses proved most sensitive to maternal diet, producing more of a protein that responds to estrogen, say researchers led by Cheryl Rosenfeld, a reproductive biologist at the University of Missouri in Columbia. The extra sensitivity could make female offspring more susceptible to estrogen-mimicking chemicals in the environment.
“The idea that maternal diet is affecting placental proteins is a neat observation,” says Retha Newbold, an emeritus reproductive and developmental biologist with the National Institute of Environmental Health Sciences in Research Triangle Park, N.C. “But the idea that it affects male and female placentas differently is really nice.”
Sex differences in response to maternal diets showed up even before fetuses developed sex organs or began producing hormones such as testosterone or estrogen, the researchers found.