Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour

Abstract

BackgroundAmong invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone.ResultsUsing wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP) of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males.ConclusionsThis involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals.See associated Commentary http://www.biomedcentral.com/1741-7007/8/71

From sexual attraction to maternal aggression: When pheromones change their behavioural significance

“…First, Jemiolo et al (1985) tested this idea and concluded that: "female's attraction to male odours was equally strong on days that they displayed vaginal oestrus to days of anoestrus". In addition, recent studies by Roberts et al (2010) using wild-derived female mice revealed a lack of preference for male volatiles, even if females in proestrous/estrous were employed. Therefore, the innate attraction of female mice towards male derived volatiles under some circumstances is still an open issue that requires further investigation.…”

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

“…Even within M. musculus, MUPs are a highly polymorphic group of proteins 35 and quantitative differences in urinary concentrations can occur in addition to qualitative ones. For example, the proportion of MUP20 (also known as darcin) among all MUPs is only o0.5% in male BALB/c but about 15% in male B6 mice 19 . Consequently, we found unique peptides from MUP20 more frequently and more abundantly in male urine of B6 than BALB/c origin (Supplementary Tables S9 and S10).…”

“…Consequently, we found unique peptides from MUP20 more frequently and more abundantly in male urine of B6 than BALB/c origin (Supplementary Tables S9 and S10). Females do not express MUP20 19,36 and, thereby, unique MUP20-derived urinary peptides are both sex specific and vary in concentration in male urine.…”

“…In contrast, more quantitative differences were observed between groups of the same inbred wild-type strain derived from different breeders 16 (for a review, see Kwak et al 17 ). Hence, whereas variability in small airborne organic molecules may be important for recognition of individual scent owners 18,19 , physical evidence for an influence of the MHC on urinary volatiles remains elusive.…”

Androstadienone’s influence on the perception of facial and vocal attractiveness is not sex specific

“…Pheromonal communication has been demonstrated in a wide range of species across the animal kingdom (Wyatt 2014) (see the pioneer work on sexual attraction in the moth related to the molecule "bombykol": Butenandt et al, 1959), including several mammals (pups' attraction toward the mother's mammary pheromone in the rabbit: Schaal et al, 2003; the Darcin effect on sexual attraction in mice: Roberts et al, 2010). Research in humans, however has led to much more ambiguous and controversial results.…”