(A) Weight of various white and brown adipose tissues from the KO and WT mice fed a high-fat diet from 12 to 24 weeks of age. Data are mean ± SEM (n = 5). (B) Size distribution of adipocytes in epididymal fat tissue of mice fed a high-fat diet from 12 to 24 weeks of age. Data are means from analysis of 5 sections from each of 5 mice. (C) Immunohistochemical detection of Mac3 in epididymal adipose tissue of mice fed a high-fat diet from 12 to 24 weeks of age. Magnification, ×200 and ×400, as indicated. Scale bars: 50 μm. (D) Macrophage infiltration into epididymal fat tissue. Data are mean ± SEM (WT, n = 8; KO, n = 6). (E) Quantitation by flow cytometry of the proportion of macrophages in the SVF of epididymal fat tissue from mice fed a high-fat diet from 12 to 28 weeks of age. Data are mean ± SEM (WT, n = 4; KO, n = 6). (F) Abundance of macrophage-related protein mRNAs in epididymal fat tissue of mice fed a high-fat diet from 12 to 24 weeks of age. Data (mean ± SEM; n = 4) were normalized by the amount of 36B4 mRNA and expressed relative to the corresponding WT value. *P < 0.05, **P < 0.01 versus WT.