In an article published by the American Association for the Advancement of Science (AAAS) Jocelyn Kaiser reports on a new study investigating links between mothers’ exposure during pregnancy and the health of their grandchildren (Radford et al. 2014). Some of the effects passed down across generations are considered to occur via chemical modifications surrounding the DNA, so known epigenetic changes. As such, children and grandchildren of mothers pregnant during the Dutch famine in 1944 were observed to be smaller, but also more prone to obesity and diabetes than children born at other times. It has also been suggested that chemical exposures during prenatal development cause epigenetically inherited effects.
In the new study published in the peer-reviewed scientific journal Science, researchers starved pregnant mice during the last week of gestation and found sperm of male offspring to have fewer methylations along about 110 stretches of DNA than control groups. The stretches identified by the scientist from the University of Cambridge, UK and Harvard Medical School, U.S. were often near genes involved in metabolism. However, these changes were not observed in the fetal tissues of the grandchildren, though they were alsomore prone to obesity and diabetes. To proof these results, Oliver Rando of the University of Massachusetts, U.S. suggests experiments in which the suspected genes are artificially turned off and on. Timothy Bestor, scientist at Columbia University, U.S. criticized that the study did not use inbred mice, potentially resulting in the survival of only those fetal mice with a particular genetic makeup and influencing the methylation patterns observed in offspring. In their study, the authors state that their regime of starvation is incompatible with successful pregnancy in inbred mice, which led them to use a non inbred strain.
Jocelyne Kaiser (July 10, 2014). “Mom’s environment during pregnancy can affect her grandchildren.” AAAS.
Radford, EJ et al. (2014). “In utero undernourishment perturbs the adult sperm methylome and intergenerational metabolism.” Science (published online July 10, 2014).