A mother’s age can influence the physical traits and behavior of her offspring in humans and across many other animal species, a phenomenon referred to as maternal age effects. Although this occurrence is widespread throughout the animal kingdom, scientists are still working to understand the biological processes underlying it and why it has persisted over evolutionary history.
Researchers from Kristin Gribble’s laboratory at the Marine Biological Laboratory have been studying rotifers, tiny aquatic animals that reproduce rapidly and are well suited for laboratory experiments. Their research suggests that maternal age effects may be controlled by epigenetic processes that change how genes are used rather than by mutations that alter the underlying DNA sequence.
The team found that these effects could be reversed within a single generation in rotifers, arguing against the idea that maternal age effects are primarily caused by gradual buildup of cellular damage or DNA mutations associated with aging. Instead, their findings point toward an epigenetic process involving histone modifications, which can influence whether genes are switched on or off. Gribble’s team is now testing whether these histone modifications are responsible for the observed maternal age effects in rotifers and considering if mitochondrial DNA could play a role in transmitting information about maternal age from mothers to offspring. Genetic differences may also determine how strongly offspring are affected by an older mother, with some gene variants potentially reducing harmful effects or even producing benefits.