Figure 4

Genome-wide linkage mapping of metabolomic features identifies a metabolite co-regulated with NAFLD. Linkage mapping data and allele effects are shown for the liver metabolomic feature at 7.34185 ppm in high fat diet (HFD) fed F2 mice. LOD scores are plotted against map distances (centimorgans) (A). A straight line indicates statistically significant LOD thresholds (P = 0.001). Effects of genotypes at the marker locus on chromosome 18 exhibiting the strongest evidence of linkage to the metabolomic feature 7.34185 ppm are illustrated by mean values (±SD) of the phenotypes calculated according to the genotype homozygous for the 129S6 or BALB/c alleles, or heterozygous at the locus (B). ¹H NMR spectrum from a representative sample revealing the peak pattern between 7.30 and 7.35 ppm is suggestive of octopamine (C).