Pheromone phenotypes

The V1r genes encode a large superfamily of receptors that are expressed in the sensory neurons of the vomeronasal organ (VNO) and are thought to be important in pheromone detection and responses. In the September 5 Nature, Del Punta et al. describe the phenotypes of mice lacking a large genomic region that contains V1r genes (Nature 2002, 419:70-74). They used the Cre-loxP system to engineer a 600 kb deletion in the mouse genome, removing a cluster of 16 genes (12% of the functional V1r repertoire). The mutant mice displayed defects in a subset of VNO-dependent behaviours, including reduced maternal aggression towards intruders and dysfunctions in male sexual behaviour. The deletion also abolished the electrophysiological response of the VNO to a subset of V1r ligands (the authors use the term "specific avnosmia").