Variability in patterns of intra-specific biting attack in commonly used genetic lines of laboratory mice

Abstract

Bite targets on opponents used by individually housed male, reproductively experienced male and lactating female subjects from outbred TO and Swiss Webster and inbred NZW/Ola, BALB/c, C57BL/10, DBA/2, CBA/Ca and C3H/He lines of mice were assessed. Ten-minute videotaped encounters with anosmic male TO or “congenic” opponents were used for this purpose. In general, the attacks shown by males appeared ‘ritualised’ with the head and ventral surface of the opponent being avoided. The lactating females showed no such inhibition. The intensity and incidence (and damaging nature of the attacks) was clearly influenced by strain of the resident, its sex, its reproductive experience and (in some cases) the nature of the opponent. This data may be helpful in controlling social stress in mouse studies. Key words: Aggression, genetic lines of mice, male, female, bite targets