The number of production sites per mm 2 (left column; n = 3 sternum segments from 3 mice) and the cellularity of each production site (right column; mean ± s.e.m.; n = 6 randomly selected production sites in three sternum segments from 3 mice) at the same time point and challenge as in b . Maps show the distribution of the indicated cells in a large region of a sternum segment. Statistical differences were calculated using two-way ANOVA t -tests if the data were normally distributed and Kruskal–Wallis test if they were not normally distributed. Scale bars, 200 m.
