Koide Group / Mouse Genomics Resource Laboratory
Increased abundance of Limosilactobacillus reuteri in the gut of selectively bred high-tameness mice and its association with behavioural changes
Bhim B. Biswa, Hiroshi Mori, Atsushi Toyoda, Kazumichi Fujiwara, Ken Kurokawa, Tsuyoshi Koide
DNA Research DOI: 10.1093/dnares/dsag006
Press Release（Japanese only）
Domestication alters animal behaviour, particularly tameness. We previously established two tamed mouse groups by selective breeding for active tameness–defined as the motivation to approach a human hand–from genetically heterogeneous wild-derived mouse stock, together with two non-selected control groups. Genetic analyses identified loci associated with active tameness, but their low heritability suggested contributions from non-genetic factors. We therefore hypothesised that the gut microbiota, which has been shown to influence brain function, contributes to behavioural changes associated with active tameness. To test this hypothesis, we conducted shotgun metagenomic analyses of faecal samples from 10 males and 10 females (80 individuals total) from the two tamed and two non-selected groups. Tamed mice exhibited markedly higher levels of active tameness, accompanied by elevated blood concentrations of oxytocin and pyruvate. While overall taxonomic and functional diversity of the gut microbiota was largely unchanged, the abundance of Limosilactobacillus reuteri was significantly increased in the tamed mice. Administration of a pyruvate-secreting L. reuteri strain to non-selected mice elevated blood oxytocin levels and enhanced active tameness, although plasma pyruvate levels were not increased. These findings suggest that L. reuteriis associated with behavioural modulation, potentially via oxytocin-related pathways, and provide mechanistic insight into microbial contributions to animal domestication.
L. reuteri (A41 strain), isolated from selectively bred high-tameness mice, promotes tameness behaviour toward humans in mice.