A. Macrophage invasion in WAT depots. Cohorts of WT and FSKO mice were maintained high-fat diets for 12 weeks as described in Figure 1. The indicated fat depots were fixed, sectioned and stained with antibodies to CD68 as described in Methods. The sections were examined by a veterinary pathologist, and scored for anti-CD68 staining. Values are means, ± SE for 4–8 mice. B. Photomicrogaphs of GWAT and IWAT stained with anti-CD68 antibodies. The crown-like structures were less frequent in FSKO WAT, and contained fewer large, CD68-positive (brown-staining) nuclei. C. Serum adipokine levels. Adipokine levels were measured in sera of WT and FSKO mice that were maintained on STD chow or HFD for 12 weeks as described in Methods. Values are means, ± SE for 3–8 mice in each group. *P < 0.05**P < 0.01.