Social dominance,sexual attractiveness and pheromonal communication in male mice Mus musculus

Previous work has shown that two urinary pheromones,E-β-farnesene and E,E-α-farnesene occur at higher concentrations in dominant male mice,and also that urinary cues enhance sexual attractiveness.These pheromones originate in the prenuptial glands,and are voided in the urine.By contrast,two pheromones which are matabolised in male urine(R,R-dehydro-exo-brevicomin,and S-2-sec-butyl-dihydrothiazole) are unaffected by social rank.The current study examined whether two recently characterized preputial pheromones(hexadecanol and hexadecyl acetate) might communicate dominance status in male mice Mus musculus.Male mice were caged in pairs for 30 consecutive days in order to allow dominance-subordinance to be established.Binary choice tests showed that the urine of dominant males was more attractive to females,than that of their subordinate male partners(but not necessarily more attractive than that of males in other pairs).Following dichloromethane extraction of preputial glandular secretions and voided urine,gas chromatography and mass spectrometry revealed that levels of E-β-farnesene and E,E-α-farnesene were elevated in dominant males(more so than levels of hexadecanol.Hexadecylacetate,R,R-dehydro=exo-brevicomin and S-2-sec-butyl-dihydrothiazole).These results suggest that,in male mice,only low molecular weight sex pheromones,of preputial glandular origin,may also serve as dominance-related pheromones.