The Number of X Chromosomes Causes Sex Differences in Adiposity in Mice
Figure 1
Increased body weight and fat mass in XX versus XY mice on a chow diet.
(A) Body weight of four core genotype (FCG) mice at day 21 and day 45, prior to gonadectomy (GDX), and at 10 months after GDX. F, gonadal female; M, gonadal male. Values represent the mean ± SEM for the number of animals indicated in each bar. Significant comparisons for sex chromosome complement and for gonadal sex are denoted by brackets. A significant interaction of sex chromosome complement and gonadal sex is denoted by “Int.”. The p values are as described at the end of the legend. (B) Body weight curve for FCG mice from the point of gonadectomy through 10 months following gonadectomy. Values represent mean ± SEM. Values are significantly different between mice with XX vs. XY genotypes beginning at week 7 following GDX and beyond that. (C) Body composition of mice in panel (B) determined by NMR in FCG mice at 10 months after GDX. (D) Fat pad mass in mice from panel (B) at 10 months following GDX expressed as absolute mass (grams) or relative to kidney weight, which is invariant among the genotypes. (E) Plasma leptin levels and leptin mRNA levels in inguinal adipose tissue. *, p<0.05; **, p<0.01; ***, p<0.001; †, p<0.0001; ‡, p<0.000001.