Figure 3. Beige and brown fat cells exhibit distinct gene expression profiles.

(A) Genes with a beige- or brown-selective expression pattern were first identified by microarray analysis as described in Supplemental Experimental Procedures. Relative mRNA expression for these genes was then measured by qPCR in differentiated brown, beige and white fat cells in an unstimulated state. (B) Analysis of beige- and brown-selective genes expression in adipose tissues isolated from inguinal WAT and interscapular BAT of 129 SVE mice. Values are mean±SD (n=5). *, p<0.05; **, p<0.01; ***, p<0.001. (C) Protein lysates of adipose tissues isolated from inguinal WAT and interscapular BAT of 129 SVE mice were probed with antibodies by immunoblot as indicated. Asterisk represents a nonspecific band as a loading control. (D) Microscopic and confocol images of mouse inguinal white and interscapular brown adipose tissue stained with antibodies recognizing CD137 (red) (microscopic images), TMEM26 (green) (confocal images) and UCP1 (green and red), with nuclei co-stained with DAPI as indicated. To induce the “browning” morphology and UCP1 expression in inguinal white adipose depot, 129SVE mice were injected intraperitoneally with CL316, 243, at 1mg kg⁻¹ daily for 4 days. Inguinal and interscapular adipose tissues were harvested on the fifth day.