Abstract
In a warfarin-resistant population of wild mice reared in the laboratory, a dominant gene for adiposity, Ad, was found to segregate. The onset of obesity is at 4--6 months, and adipose mice suffer from hyperinsulinaemia; the sexes differ in penetrance, males having greater penetrance then females. Linkage backcrosses show the gene to be situated on chromosome 7 with about 25% recombination with the closely linked warfarin-resistance genes War, and frizzy, fr. The finding of adipose in two other wild populations also carrying War is discussed as an ecological and physiological problem.