Nonallelism for the audiogenic seizure prone (Asp1) and the aryl hydrocarbon receptor (Ahr) loci in mice.

Previous studies showed an association between the Ahr locus on Chr 12 and a major gene, Asp1, that influences susceptibility to audiogenic seizures (AGS) in mice. Although the association was thought to involve close linkage, a pleiotropic effect of the Ahr locus on AGS susceptibility was not excluded. Two congenic strains, D2.

The mahogany protein is a receptor involved in suppression of obesity.

Genetic studies have shown that mutations within the mahogany locus suppress the pleiotropic phenotypes, including obesity, of the agouti-lethal-yellow mutant. Here we identify the mahogany gene and its product; this study, to our knowledge, represents the first positional cloning of a suppressor gene in the mouse. Expression of the mahogany gene is broad; however, in situ hybridization analysis emphasizes the importance of its expression in the ventromedial hypothalamic nucleus, a region that is intimately involved in the regulation of body weight and feeding.