Odour signals major histocompatibility complex genotype in an Old World monkey

Abstract

The major histocompatibility complex (MHC) is an extraordinarily diverse cluster of genes that play a key role in the immune system. MHC gene products are also found in various body secretions, leading to the suggestion that MHC genotypes are linked to unique individual odourtypes that animals use to assess the suitability of other individuals as potential mates or social partners. We investigated the relationship between chemical odour profiles and genotype in a large, naturally reproducing population of mandrills, using gas chromatography-mass spectrometry and MHC genotyping. Odour profiles were not linked to the possession of particular MHC supertypes. Sex influenced some measures of odour diversity and dominance rank influenced some measures of odour diversity in males, but not in females. Odour similarity was strongly related to similarity at the MHC, and, in some cases, to pedigree relatedness. Our results suggest that odour provides both a cue of individual genetic quality and information against which the receiver can compare its own genotype to assess genetic similarity. These findings provide a potential mechanism underlying mate choice for genetic diversity and MHC similarity as well as kin selection.

Color in competition contexts in non-human animals

“…For example, colour in mandrills is part of a suite of visual, olfactory and acoustic traits (Darwin, 1871;Osman Hill, 1970). While male mandrill colour and odour both signal age and rank, they also reflect different aspects of the male: red signals testosterone and some MHC genotypes, while odour encodes genetic diversity and genetic similarity (Setchell et al, 2011(Setchell et al, , 2009Setchell, Vaglio, et al, 2010). Similarly, red colour and barks in male rhesus macaques have the potential to convey different information to the perceiver (Higham et al, 2013).…”

The hidden benefits of sex: Evidence for MHC‐associated mate choice in primate societies

“…Analyses of the content of chemical signals suggest that they can advertise individual traits in ring-tailed lemurs [42], mandrills [55] and humans [56]. Moreover, odour signals genome-wide diversity and genetic relatedness in ringtailed lemurs [42,57] and mandrills [58], as well as MHC diversity and dissimilarity in mandrills [58]. A final piece of evidence arises from the famous 'sweaty T-shirt' experiments in humans, which complement correlative designs in nonhuman primates by showing that MHC-associated olfactory cues are perceived, and may even influence mating preferences [15,16].…”

Semiochemical compounds of preen secretion reflect genetic make-up in a seabird species

“…Most of these studies have shown a link between genetic relatedness at major histocompatibility complex (MHC) loci and body scent [11,17,19,21,22]. The MHC is an extremely polymorphic complex of genes that plays a critical role in immune response and disease resistance.…”