Genetic control of plasma cholesterol response in the rat

The inheritance of the susceptibility for dietary cholesterol in the rat has been studied by testing the plasma cholesterol response in male animals from crosses between hyperresponding and hyporesponding inbred strains. Comparison of the variances of the response of genetically uniform groups (parental strains and F1 hybrid) and segregating groups (backcrosses and F2 hybrid) revealed that more than 80 percent of the observed variation can be attributed to additive genetic factors and indicated that two major genes are involved in the control of the plasma cholesterol response.