Female preference for male saliva: Implications for sexual isolation of Mus musculus subspecies

We studied the effects of a single genetic change on a complex mammalian be havior using animals congenic for two variants of Abpa, the gene for the al pha subunit of mouse salivary androgen-binding protein (ABP), in two-way pr eference tests. Females exhibited a preference for investigating salivas of males of their own genetic type of ABP but not for urines of either type o f male. This preference behavior is consistent for samples of mice from geo graphically diverse populations of Mus musculus domesticus and M. in. muscu lus. These findings provide an explanation for the observation that this ge ne is evolving under strong selection.