QTL on Chr 1, Chr 4, and Chr 9 show complex patterns of gene X diet interactions. (A-D) Plots of genotypic values at the QTL peak (X axis) are shown for four different OTUs where the QTL shows differential effects depending on whether the G10 mice were fed the control or the high-fat diet. Relative abundances of the OTUs for animals having the HR/HR parental, HR/B6 heterozygote, or B6/B6 parental genotypes at QTL peak are plotted on the Y-axis. (A) QTL for OTU15028 at 49.1 Mb on Chr 1. (B) QTL for Butyricoccus at 127 Mb on Chr 1. (C) QTL for OTU17889 at 12.5 Mb on Chr 4. (D) QTL for OTU13989 at 40.7 Mb on Chr 9. Error bars based on standard error.