Towards an understanding of the pregnancy-blocking urinary chemosignals of mice

Abstract

Male mouse urine contains a pregnancy-blocking chemosignal that causes pre-implantation pregnancy failure in recently mated female mice. However, females are able to recognize the chemosignal of the male with which they mated, preventing it from aborting his own offspring. The individuality of the pregnancy-blocking chemosignal is influenced by genes of the major histocompatibility complex (MHC), although the chemical nature of the signal remains unclear. Possible candidates include fragments of MHC proteins, the highly polymorphic major urinary proteins (MUPs) and the profile of low-molecular-mass volatiles, which possess male pheromonal activity in other contexts. A recent study has found a high-molecular-mass fraction of male urine containing MUPs to be ineffective in eliciting pregnancy block. Moreover, both the pregnancy-blocking activity and the individuality of the signal were associated with the low-molecular-mass fraction of male urine.

Scent marking behavior as an odorant communication in mice

“…Females appear to form an olfactory memory of the stud male in the accessory olfactory bulb shortly after mating (Brennan et al, 1990;Brennan and Peele, 2003). This is mediated by prolactin and LH, to stimulate neuronal production in the olfactory bulb and hippocampus, respectively (Mak et al, 2007).…”

The ABCs of MHC

“…87 In humans, more than forty studies have examined the relationship between the MHC and reproductive outcome (reviewed in Choudhury and Knapp 88 ). Like the rodent studies, these efforts have produced conflicting conclusions about the influence of the MHC on reproductive success.…”

Detective mice assess relatedness in baboons using olfactory cues

“…The next step is to identify the composition and the chemical properties of odour labels produced by baboons and used by mice, thanks to complementary experiments with mice, possibly coupled with chemical analyses. Previous studies, essentially in rodents, indicate that the scents associated with the MHC can be used to recognise kin (Yamazaki et al, 1983;Roser and Singh, 1991;Potts et al, 1991;Manning et al, 1992;Brennan and Peele, 2003), although similar effects are not documented in baboons. The MHC is a highly polymorphic gene complex that has been shown to influence the volatile scent profiles of mice (Yamazaki et al, 1979;Carroll et al, 2002), rats (Singh et al, 1987) and humans (Wedekind and Furi, 1997;Jacob et al, 2002).…”