The Tube Test fails to predict social dominance in across two strains of mice

Abstract

Mice form social hierarchies that can determine access to limited resources and overall health. Accordingly, social rank strongly influences behavioral and physiological health. The Tube Test is an established method used to identify social rank in mice and its rapidity and simplicity have made it a popular tool to understand mouse social relationships; however, this test is not universally accepted as a reliable and objective measure of social dominance. To address its controversial validity, we compared performance in the Tube Test to home cage aggression, home cage activity, preputial gland size, and steroid hormone levels, all of which are indicators of dominance or social stress in mice, but are less utilized because of the high expense and intense labor involved. We used young adult male mice housed in dyads, and evaluated these measures over 29 days. To broaden the impact of this study, we used dyads of both outbred CD-1 and inbred C57 mice. Tube Test performance had no ability to predict qualities associated with behavioral or physiological dominance, suggesting that caution should be taken when using the Tube Test to predict dominance relationships in mice. Our study does, however, suggest that the Tube Test may offer some utility in alternative contexts.