Fig.4.

A novel QTL, Dserum8a, associated with variation in cholesterol. In high-fat fed females, there is a significant additive effect, where LG homozygotes have higher cholesterol than SM homozygotes (B). This effect does not register as significant in the full population because the signal is washed out by absence of genetic effects in the other sex-by-diet cohorts (A). Further, high-fat fed females have significant maternal expression imprinting, where animals inheriting their LG allele from their mothers have higher cholesterol (B). In low-fat fed males, there is significant bipolar dominance imprinting (C). Imprinting effects do not register in the full population because the negative value in the females and the positive value in the males cancel each other out (A). *P < 0.05. LG, allele derived from the LG/J strain; QTL, quantitative trait loci; SM, allele derived from the SM/J strain.