GENOTYPE PECULIARITIES OF OLFACTORY COMMUNICATION IN LABORATORY MALE MICE (MUS MUSCULUS) IN A SOCIAL COMPETITION MODEL

摘要

Olfactory communication plays important roles in the establishment and maintenance of social dominance. In males of the house mouse, urinary scent marking and sniffing behaviour depend on the dominance status: the dominants more intensely mark the territory and more often sniff the opponents compared to the subordinates. Previously we showed that the capacity to dominate in laboratory mice is mainly determined by the genotype of the male. However, it remains unclear if the peculiarities of urinary marking and sniffing behaviour in the male could predict its future social position in the hierarchical structure of a community. The objective of the present work was to establish the effect of the genotype on the intensity of sniffing and marking behaviour in a social hierarchy and to study the relationship between these behaviours and a genetic predisposition to social dominance in laboratory male mice. The study was carried out using adult male mice of the inbred strains BALB/cLac, CBA/Lac and PT, which differ in their ability to dominate: males of the BALB/cLac and PT strains mainly dominated over CBA/Lac males. The experimental groups were formed of two males of different genotypes in all three possible pairwise combinations. Territorial urine marking (the number of urine marks) was evaluated for each male during social isolation and after the development of stable hierarchical relations in the group. The genotype differences were established in urinary marking patterns of isolated males: the CBA/Lac males urinated more often than those of the other strains. After males had been placed as pairs for 5 days for the establishment of dominance-subordination relationships, scent marking and sniffing behaviour were observed suppressed in subordinate males. The genotype differences were established in urinary marking patterns among dominants: the CBA/Lac males marked the territory and sniffed the opponent much more often than the BALB/cLac or PT males, although they became dominants very infrequently. Thus, scent marking and sniffing behaviour in laboratory mice are related to each other, but the genetic peculiarities of olfactory communication cannot predict the social status of a male.