Research on animal models continues to shed light on the genetic component of obesity. For several decades, genetic studies on rats and mice have yielded substantial information regarding the development of obesity, its accompanying symptoms and the tendency for individuals to relapse during treatment for obesity. "The techniques of molecular biology and genetic mapping have provided additional information that has made it possible, in some cases, to actually locate obesity genes on the rat and mouse chromosomes and to specify genetic markers adjacent to those genes," says M.R.C. Greenwood, professor of nutrition and dean of graduate studies at UC Davis. She notes, however, that an obesity gene has not yet been identified in humans, although consensus among researchers is that obesity in humans is tied closely to heredity. Greenwood will deliver a keynote address on "Genetic Models of Obesity" at 8 a.m. Tuesday, Oct. 22, in the Regency Ballroom. In addition to discussing recent findings in the molecular biology of rodent models, she will explain how the particular strain of research animal appears to influence manifestation of obesity-related diabetes, which might have implications for ethnic differences in humans. Greenwood's work was done in collaboration with Patricia R. Johnson, adjunct professor of nutrition.