Sex drives colonic mucin sialylation in wild mice.

Mucin protein glycosylation is important in determining biological properties of mucus gels, which form protective barriers at mucosal surfaces of the body such as the intestine. Ecological factors including: age, sex, and diet can change mucus barrier properties by modulating mucin glycosylation. However, as our understanding stems from controlled laboratory studies in house mice, the combined influence of ecological factors on mucin glycosylation in real-world contexts remains limited. In this study, we used histological staining with 'Alcian Blue, Periodic Acid, Schiff's' and 'High-Iron diamine' to assess the acidic nature of mucins stored within goblet cells of the intestine, in a wild mouse population (Mus musculus). Using statistical models, we identified sex as among the most influential ecological factors determining the acidity of intestinal mucin glycans in wild mice. Our data from wild mice and experiments using laboratory mice suggest estrogen signalling associates with an increase in the relative abundance of sialylated mucins. Thus, estrogen signalling may underpin sex differences observed in the colonic mucus of wild and laboratory mice. These findings highlight the significant influence of ecological parameters on mucosal barrier sites and the complementary role of wild populations in augmenting standard laboratory studies in the advancement of mucus biology.