DIETARY OBESITY LINKED TO GENETIC-LOCI ON CHROMOSOME-9 AND CHROMOSOME-15 IN A POLYGENIC MOUSE MODEL

Loci linked to sensitivity to dietary obesity were identified by Quant itative Trait Locus (QTL) analysis of two mapping populations derived from a cross between AKR/J and SWR/J mice. AKR/J mice are sensitive to dietary obesity when fed a high fat diet while SWR/J mice are resista nt. Intercrosses between these strains segregate the phenotype of sens itivity to dietary obesity. Using an F2 mapping population of 931 male mice we found significant linkage with a QTL on chromosome 9 (Likelih ood of the Odds [LOD] ratio of 4.85) and another QTL on chromosome 15 (LOD = 3.93), The presence of a QTL on chromosome 15 was confirmed in a separate mapping population of 375 male F1 x SWR/J mice (LOD = 3.82) . These two loci are designated dietary obese 2 (Do2) and dietary obes e 3 (Do3) for the chromosome 9 and 15 loci, respectively. Both of thes e chromosomal regions contain candidate genes which may contribute to variation in the phenotype. These loci also exert a significant contro l over individual adipose depot weights.