Studies with B6-cast congenic mice bearing mid-to-distal chromosome 7 genes that confer resistance to obesity: Mechanisms involved.

The congenic mouse model studied herein is a mouse lineage in which a 26cM chromosomal segment on mid-to-distal chromosome 7, including the UCP2 and UCP3 genes from Mus Castaneous has been bred into the C57BL/6J background. The resulting congenic mice remain lean on a high fat diet. Control C57BL/6J mice on the same diet become almost twice as fat as the congenic mice. It was postulated that protection from obesity development could be due to functional differences in the UCP2 and/or UCP3 mapping in this region. The overall objective was to determine the metabolic basis for the observed differential susceptibility to fat deposition between congenic and control mice fed a high fat diet. We examined aspects of both energy intake and energy expenditure. Three separate studies were conducted with three sets of congenic and control mice. In the first study, the mice were fed a normal chow diet for 4.5 weeks. In the second and third studies they were fed a high fat diet for 6 weeks. (Abstract shortened by UMI.