The sex bias in novelty preference of preadolescent mouse pups may require testicular Mullerian inhibiting substance

Male mouse pups exhibit elevated preference for novelty relative to their sisters. The testes of pups secrete high levels of Mullerian inhibiting substance (MIS, anti-Mullerian hormone), with neurons being a target of this hormone. We report here that male pups exhibit novelty preference, but their Mis(-/-) brothers and Mis(+/+) sisters do not. This suggests that MIS is one of the determinants of boy-specific behavior. (C) 2011 Elsevier B.V. All rights reserved.