Individual recognition in mice mediated by major urinary proteins

Abstract

The ability to recognize individuals is essential to many aspects of social behaviour, such as the maintenance of stable social groups, parent-offspring or mate recognition, inbreeding avoidance and the modulation of competitive relationships. Odours are a primary mediator of individuality signals among many mammals. One source of odour complexity in rodents, and possibly in humans, resides in the highly polymorphic major histocompatibility complex (MHC). The olfactory acuity of mice and rats allows them to distinguish between the urinary odours of congenic strains differing only in single genes within the MHC, although the chemical mediators or odorants are unknown. However, rodent urine also contains a class of proteins, termed major urinary proteins (MUPs), that bind and release small volatile pheromones. We have shown that the combinatorial diversity of expression of MUPs among wild mice might be as great as for MHC, and at protein concentrations a million times higher. Here we show in wild house mice (Mus domesticus) that urinary MUPs play an important role in the individual recognition mechanism.

Mouse urinary peptides provide a molecular basis for genotype discrimination by nasal sensory neurons

“…We have identified a novel family of MHC-independent peptides that differ in strains by single aminoacid exchanges, and we show for the first time (see Supplementary Note 1) that a bona fide MHC peptide ligand exists in urine in an MHC-dependent manner at biologically relevant concentrations. Hence, the emerging picture is a complex scenario in which multiple peptide families together with previously characterized MUPs 35,49,50 , formylated and maternally inherited peptides (not yet shown to exist in urine) 25 and possibly other yet undiscovered ligand families link the genotype of an individual with nasal chemoreception mechanisms. Future research should examine the contribution of these peptides to genotype discrimination in diverse behavioural contexts, but it will be essential to select urine samples for such experiments with care.…”

The influence of preexperimental experience on social discrimination in rats (Rattus norvegicus).

“…Johnston & Bullock 2001) or urinary excretion (e.g. Hurst et al, 2001). In addition to the role of the major histocompatibility complex in signalling individuality (e.g.…”

“…In addition to the role of the major histocompatibility complex in signalling individuality (e.g. Brown et al, 1987), rodent urine contains major urinary proteins (MUPs) that have been found to play an increasingly important role in individual recognition (Hurst et al 2001). Major urinary proteins also bind and release volatile pheromones that themselves can influence biological processes such as reproduction (e.g.…”

High resolution X‐ray structures of mouse major urinary protein nasal isoform in complex with pheromones

“…[10][11][12][13] It has also been shown that expression patterns of the 8-14 excreted group 1 isoforms are similar among related mice, 5,8,14 which suggests that the MUP protein profile might also play a role in social communication. [15][16][17][18] The precise roles of the group 4 isoforms are currently unclear. In rodents, pheromones are detected both by the main olfactory bulb and the vomeronasal organ (VNO).…”