Flipping a single genetic swap could make doting dads assault their offspring, not less than in African striped mice, new analysis suggests. However the gene itself wasn’t solely accountable for this swap from attentive to aggressive fathering; social circumstances additionally performed a task in how the male mice behaved.
The findings may reveal extra concerning the genetic mechanisms that lead some species of mammals to behave as caring fathers whereas others abandon their younger. Energetic fathering is uncommon in mammals, with solely 5% of the 6,000 mammalian species having concerned dads. Due to this, scientists know far much less about how paternal care works in mammals than they find out about maternal care in mammals. African striped mice (Rhabdomys pumilio) are helpful for learning mammalian paternal care as a result of males present a variety of behaviors towards pups, from huddling to maintain pups heat to actively ignoring their progeny.
To find out the mind areas that mediated this habits, the crew uncovered male mice to pups, then monitored their mind exercise. They discovered the attentive dads had better exercise in a single mind area, referred to as the medial preoptic space (MPOA).
“Many years of labor has proven that the MPOA acts as a hub for maternal care throughout mammals,” lead creator and postdoctoral researcher Dr. Forrest Rogers, a researcher on the Princeton Neuroscience Institute, informed Stay Science in an e-mail.
The crew then dissected the brains of the mice and measured gene exercise in cells from the MPOA. From this, they found {that a} gene referred to as Agouti was extra lively in males that attacked pups than in males that cared for the pups.
“Agouti is healthier recognized for its roles in pores and skin pigmentation and metabolism, so discovering this beforehand unknown function within the mind for parenting habits was thrilling,” Rogers mentioned in a assertion.
To substantiate that Agouti expression was accountable for the transition between attentive and aggressive habits, the crew first uncovered mice to pups, then injected a virus that amped up the expression of the Agouti gene within the MPOA. When the males had been uncovered once more to pups, their habits modified.
“We discovered that these males, when Agouti was elevated, grew to become aggressive towards pups,” Rogers informed Stay Science in an e-mail, suggesting that this gene was appearing as a kind of “swap” that flipped between aggressive and caring habits in mouse fathers.
Whereas the Agouti gene discovered inside the MPOA could have a powerful hyperlink to the change in paternal care, Rogers cautioned that this molecular swap wasn’t the entire story.
“It definitely appears that for some striped mice, rising Agouti expression is adequate to induce infanticide,” he mentioned. “Nevertheless, we additionally discovered that there have been different elements at play, for instance, the present social housing, which may average this impact.”
When the researchers moved males from group housing to solitary cages, Agouti ranges dropped and caregiving elevated, suggesting that the gene is influenced extra by social context than by meals availability.
Whereas this examine could have uncovered a attainable genetic swap for fathering, there have been key limitations. Notably, solely male African striped mice had been studied. And though fathering habits different inside the species, the researchers cautioned towards translating these findings to different species.
“Whereas we can’t rule out that Agouti may operate equally in different species (people or others), there is no such thing as a present proof suggesting this particular operate in people (or different mammalian species),” Rogers mentioned in his e-mail to Stay Science.
Rogers, F. D., Kim, S., Mereby, S. A., Kasper, A. M., Callanan, A. B., Mallarino, R., & Peña, C. J. (2026). Agouti integrates environmental cues to manage paternal behaviour. Nature. https://doi.org/10.1038/s41586-026-10123-4
