Fat mice tell little

Separate reports delving further into two obesity-related gene defects in mice have shed only a little more light on what could cause humans to become overweight. Neither the ob or fat mouse gene appears to be a clear factor in human obesity.

The ob gene found in mice is not defective in obese humans, researchers at Jefferson Medical College reported in the Journal of Clinical Investigation. Meanwhile, another mouse gene, fat, maps to, and appears to be coding, the enzyme that cleaves insulin from proinsulin, its prohormone. The defective enzyme causes improper processing of insulin in mice, but there is only one documented case in humans of a proinsulin-processing defect...