Fig. 4

Il1rn^−/−XS100a9^−/− and Il1rn^−/− osteoclast precursors have a comparable osteoclastogenic potential in vitro. Photomicrographs of tartrate-resistant acid phosphatase staining of in vitro differentiated osteoclasts derived from bone marrow cells of wild type (WT), S100a9^−/−, Il1rn^−/−, and Il1rn^−/−XS100a9^−/− mice (A, original magnification ×40). Quantification showed an increased formation of big (6 or more nuclei) osteoclasts in Il1rn-deficient strains compared to S100a9^−/− and WT control cells. No differences were present between Il1rn^−/− and Il1rn^−/−XS100a9^−/− cells (B). Scatterplots are shown, with horizontal and vertical lines representing mean ± SEM values. *P < 0.01. Results of the two-way ANOVA with interaction are presented in the table