Fig. 3

RMT from mastitis cows to mice induces mastitis in mice. A. Experimental protocol of RMT. Mice were mated for 3 days. After confirming pregnancy, these mice were treated with an antibiotic cocktail for 5 days to deplete the commensal microbiota and performed RMT for 26 days. B. Histological analysis of mammary tissues using H&E-stained sections. Black arrows indicate leukocyte infiltration and red arrows show barrier damage (scale bar, 25 or 50 μm). C Histological scores of the mammary glands from the indicated groups based on H&E-stained sections (n = 7). Mammary TNF-α (D) and IL-1β (E) concentrations and MPO activity (F) were measured (n = 7). Representative protein levels of mammary ZO-1, occludin, and claudin-3 (G) and intensity analysis of ZO-1, occludin, and claudin-3 from different recipient mice (H) were assessed (n = 3). Data are expressed as the mean ± SD (C–F, H). One-way analysis of variance (ANOVA) was performed, followed by Tukey’s test (C–F, H). *p < 0.05, **p < 0.01, ***p < 0.001 indicate significance