Fig. 1.
A, No differences are seen between 3- and 4.5-month-old control and mutant animals in total mean body weights and average lean body mass. Lean body mass (M3/4) was calculated according to Kleiber's law (26, 27). Statistical analysis was done in Prism (GraphPad) with one-way ANOVA followed by Newman-Keuls and Bonferroni multiple comparisons tests. B, There are no changes in serum leptin in deletion mutant males or females, although leptin levels are lower in the control and deletion mutant females than they are in the males (P < 0.0001, Bonferroni). The levels for both males (n = 42 controls, n = 38 mutants) and females (n = 27 controls, n = 45 mutants) are within the normal range reported for the mouse, however. C, There was a higher food intake during all dark phases of the 72-h test period in males but no differences between the two groups (control vs. deletion mutant). D, Deletion mutant females ate significantly more food during all light and dark phases of the 72-h test period (P < 0.0001, Bonferroni). E, During the dark phases of the test period, mutant females ate more food at each feeding bout (P = 0.0023, Bonferroni). F, A significant increase in ghrelin in females is shown, which correlates with their increased food intake (P = 0.0087 Bonferroni n = 6) but no changes in serum ghrelin in deletion mutant males (n = 9, Bonferroni). *, Significantly greater than control values; °, significantly different from values in light phase or significantly different from males