Molecular organization of vomeronasal chemoreception

Abstract

The vomeronasal organ (VNO) plays a key role in mediating the social and defensive responses of many terrestrial vertebrates to species- and sex-specific chemosignals1. Over 250 putative pheromone receptors have been identified in the mouse VNO2,3, but the nature of the signals detected by individual VNO receptors has not yet been elucidated. In order to gain insight into the molecular logic of VNO detection leading to mating, aggression, or defensive responses, we sought to uncover the response profiles of individual vomeronasal receptors to a wide range of animal cues. We describe here the repertoire of ethological and physiological stimuli detected by a large number of individual vomeronasal receptors, and define a global map of vomeronasal signal detection. We demonstrate that the two classes of vomeronasal receptors V1Rs and V2Rs use fundamentally different strategies to encode chemosensory information, and that distinct receptor subfamilies have evolved towards the specific recognition of certain animal groups or chemical structures. The association of large subsets of vomeronasal receptors with cognate, ethologically and physiologically relevant stimuli establishes the molecular foundation of vomeronasal information coding, and opens new avenues for further investigating the neural mechanisms underlying behavior specificity.

Mouse alarm pheromone shares structural similarity with predator scents

“…Interestingly, SBT shares its chemical structure with a different class of odorant molecules also involved in danger communication: the molecules found in rodent predator scents (44)(45)(46) (Fig. 2 C and H).…”

Roles of sex and gonadal steroids in mammalian pheromonal communication

“…These sulfated steroids activated consistent groups of 25-50% of all of the sensory neurons in the apical zone (abutting the lumen) of the VNO of male mice. Isogai et al (2011) used expression of an immediate early gene, Egr1, as an index of VNO sensory neuron activation in CD-1 male mice, to monitor effects of sulfated steroids. Neurons in the apical VNO that express receptors of the V1R type showed reliable Egr-1 activation in response to several different sulfated steroids applied directly to the males' nares 40 min prior to sacrifice.…”

Molecular Switches in the Development and Fate Specification of Vomeronasal Neurons: Figure 1.

“…V1r-expressing neurons are largely sensitive to small lipophilic molecules, whereas V2r-expressing neurons respond primarily to peptides (Leinders-Zufall et al, 2000. Also, while individual V1r-neurons respond to scents from multiple, even contrasting, ethological contexts, such as conspecific, predatory, and nonpredatory semiochemicals, V2r-expressing neurons are mostly activated by compounds from a single ethological category, such as scents from a predator or a male or a female conspecific (Isogai et al, 2011).…”