title: Sexual attractiveness in male rats is associated with greater concentration of major urinary proteins.
abstract: Female rats show a distinct attraction for males. This attraction remains consistent without the necessity for the physical presence of the male. However, the identity of the olfactory cues contributing to attraction in rats remains unknown. Rat urine contains copious amounts of major urinary proteins (MUPs). Here, we investigated the hypothesis that MUPs mediate sexual attractiveness in rats. We first demonstrated that a member of a male dyad receiving greater copulatory opportunities in competitive mate choice tests excrete greater amounts of MUPs. Furthermore, the amount of male MUPs positively correlated with both copulatory opportunities received and female exploration of the urine. Using females and a two-choice olfactory attraction test, we demonstrated that urinary fractions containing MUPs were sufficient to induce attraction and that male MUPs activated neurons in the posterodorsal medial amygdala in female rats. Taken together, these results suggest that olfactory cues associated with MUPs act as an attractant to female rats in estrus.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Vineet
authors.initials: V
authors.lastname: Kumar
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Anand
authors.initials: A
authors.lastname: Vasudevan
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Linda Jing Ting
authors.initials: LJ
authors.lastname: Soh
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Choo
authors.initials: C
authors.lastname: Le Min
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Ajai
authors.initials: A
authors.lastname: Vyas
authors.affiliation: Department of Chemistry and Biochemistry, Southwestern University, Georgetown, Texas.
authors.forename: Maha
authors.initials: M
authors.lastname: Zewail-Foote
authors.affiliation: Department of Psychology, Southwestern University, Georgetown, Texas guarracf@southwestern.edu.
authors.forename: Fay A
authors.initials: FA
authors.lastname: Guarraci
mesh_terms: D000818:Animals; D002755:Choice Behavior; D003163:Competitive Behavior; D005260:Female; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D017208:Rats, Wistar; D012724:Sex Attractants / Q000652:urine*; D012903:Smell
chemical_list: D011506:Proteins; D012724:Sex Attractants; C035737:major urinary proteins
keywords: female sexual motivation; major urinary proteins; mate choice; pheromones; reproductive success