Figure 5.
Comparison of principal components derived from individual fat distributions. Values of principal components are shown across the founder strains. Vertical error bars represent the observed mean ± standard deviation. Both components significantly differed among strains (P < 0.0001). The obese NZO/HILtJ strain had significantly higher values of PC1 compared to all other strains, reflecting the positive correlations between PC1 and all fat volume measures (see also Table 1). Results suggest this component is highly heritable, with an h2 (95% CI) of 0.837 (0.771, 0.903). Heritability is reduced by ∼50% when adjusting for body weight (0.439 [0.271, 0.608]). For PC2, which was most strongly correlated with intra-neck fat and pericardial fat volumes, the C57BL/6J mice have higher values than all other strains. This second component has high heritability (0.643 [0.532, 0.754]), which remains nearly identical after controlling for body weight (0.655 [0.548, 0.761]). Thus, results support a genetic influence on fat distributions, independent of general obesity.