Simply by transferring a gene, scientists report, they can transform promiscuous male meadow voles into monogamous animals—evidence that the ability to form lasting relationships is dictated to a great degree by genetics.
In the brains of prairie voles (which are monogamous), high levels of receptors for the neurochemical vasopressin are found in the ventral pallidum—one of the brain's "reward centers." Meadow voles, which seek out multiple partners, lack vasopressin receptors in the ventral pallidum. To see if this difference could help to explain the mating behavior of the two types of voles, Miranda Lim and colleagues used a harmless virus to transfer the vasopressin receptor gene from prairie voles into the ventral pallidum of male meadow voles.
The researchers found that in response to the gene transfer and resulting increase in vasopressin receptors, the meadow voles began to display a strong preference for their current partners, rather than seeking out new females. While Lim et al. note that many genes are involved in mating behavior, they say, "Our study… provides evidence, in a comparatively simple animal model, that changes in the activity of a single gene can profoundly change a fundamental social behavior of animals within a species."
"Enhanced partner preference in a promiscuous species by manipulating the expression of a single gene," M. M. Lim, Z. Wang, D. E. Olazabal, X. Ren, E. F. Terwilliger, and L. J. Young, Nature, Vol. 429, No. 6993, June 17, 2004, 754-7. Address: Miranda Lim, Center for Behavioral Neuroscience, Emory University, Atlanta, GA 30322. See also: "Researchers make promiscuous animals monogamous by manipulating genes," news release, Emory University, June 16, 2004.