Genes involved in animal models of obesity and anorexia

Pathological deviations in bodyweight is a major increasing health problem in industrialized societies. It is currently unclear what genetic mechanism s are involved in the long-term control of human bodyweight and to what ext ent these genes are involved in pathological deviations of bodyweight contr ol such as anorexia and obesity. Major support for the concept of genetic c ontrol of bodyweight has recently emerged from different animal models. A n umber of new genes have been found during recent years that, when mutated, have a negative effect on bodyweight in animals and sometimes also in man. Although available evidence points toward a multifactorial nature of weight disorders in most human subjects, the single genes isolated in animal mode ls may become powerful tools to elucidate the genetics also in man. In addi tion, these genes may serve to promote the development of targeted small-dr ug pharmaceuticals aimed at novel biochemical pathways. Finally, the uncove ring of several quantitative trait loci (QTL) influencing body mass, body f at or fat topography in the mouse and rat has now also made it possible to perform studies of polygenically caused obesity in rodents. The role of the Genome Project in developing a complete gene map will greatly facilitate t ransforming these QTLs to actual molecules involved in the biology of bodyw eight.