For mice, domestication is a ten generation process, and while we’re left wondering at what stage Toronto Mayor Rob Ford is caught up in, we’ll try to steer clear of any low brow jokes. During the process of domestication many adaptations occur, but not all are beneficial. In fact, as a thought provoking group from the University of Utah showed, sometimes the transition from field mouse to barn mouse triggers a reduced output of pheromones via epigenetic mechanisms. In other words, they lose their sexiness.

First author Adam Nelson, shares that “Pheromones are the language of mice. When females mate in a socially competitive environment, they program their sons to have a head start by producing more pheromones.” Senior author Wayne Potts adds, “Sons are primed to respond to conditions that their moms experienced – such as exposure to multiple potential mates.” And while this research isn’t a technical breakthrough, it certainly is a theoretical one.

Here’s what the group deduced:

Males with promiscuous mothers were way better at attracting mates, which is due to the inherited higher expression of the sexy gene (Mup11) when compared to males with monogamous moms.

This phenotype was caused by “sociality-driven maternal and paternal effects”, suggesting behavior is affecting gene expression through transgenerational DNA methylation.

Mup11 regulation isn’t driven by hormone transduction pathways, but is actually caused by a reduction in promoter DNA methylation.

Intriguingly, there also appears to be a potential for paternal effects, and there is even a conflict amongst parents and offspring over pheromone expression. “Fathers are competing with their sons and usually drive them out of the territory quickly, while they let daughters stay,” concludes Potts. “If you’re worried about your sons impinging on your own reproductive success, then why make them sexy?”

Delve into the world of DNA methylation and mouse attraction at PNAS, November 2013