Figure 3

Independent of sex and presence of gonads, cold exposure induces BAT Fgf1 and Bmp8b expression. (A) Change in body weight and food intake of sham-operated and GDX’d male and female mice during exposure to 4°C or 23°C for 24 h. (B) Ucp1 mRNA expression in BAT of male and female mice upon GDX or sham operation and exposure to 4°C or 23°C for 24 h. (C) Immunoblot of UCP1 and α-tubulin and quantification of UCP1 protein vs. α-tubulin protein content in BAT of male and female mice upon GDX or sham operation and exposure to 4°C or 23°C for 24 h. UCP1 protein results were normalized with data from sham-operated male mice exposed to 23°C defined as ‘1’, n = 4. (D) Bmp8b and Fgf1 mRNA expression in BAT of male and female mice upon GDX or sham operation and exposure to 4°C or 23°C for 24 h. mRNA expression results were normalized to 18S ribosomal RNA (Rn18s) and beta-2 microglobulin (B2m) with data from sham-operated male mice exposed to 23°C defined as ‘1’. Values are averages ± SEM; n = 4–6; *p < 0.05 4°C vs. 23°C for the same animal model (Mann–Whitney U test); #p < 0.025 (Mann–Whitney U post hoc test when significance was detected by two-way ANOVA for mice exposed to 23°C); $p < 0.025 (Mann–Whitney U post hoc test when significance was detected by two-way ANOVA for mice exposed to 4°C). Depicted below the graphs are the significant p values of the two-way ANOVA tests for either (S), GDX (G), or the interaction between sex and GDX (SxG) for mice exposed to either 23°C or 4°C.