Fruit fly gene combats wasting disorder.

• Position: Molecular Biology

A gene regulating muscle formation in fruit flies could play a vitally important role in a wasting disorder in humans, researchers at the University of Texas Southwestern Medical Center at Dallas have discovered. "This study illustrates the way in which dissecting a basic problem in developmental biology can lead to unexpected connections to human disease," notes Eric Olson, chairman of molecular biology and senior author of the study.

"Who could have ever anticipated that studying an ancient gene that regulates muscle development in fruit flies could provide a window into understanding a wasting disorder in humans? That's really the beauty of biology and one of the gratifying aspects of this project for us."

Olson and his colleagues are examining the evolutionary conservation of developmental mechanisms, focusing specifically on muscle development and how a gene in a fruit fly can play the same function in a mouse. One gene, known as twist, encodes a gene-regulatory protein controlling muscle formation in fruit flies, and the researchers' initial hypothesis was that the function of the gene in both organisms would be identical.

After four years of study, however, the researchers found otherwise. Unexpectedly, mice genetically engineered to lack twist were underweight, frail, and developed cachexia, a severe wasting disorder that is commonly associated with cancer, AIDS, and chronic infection in humans. "The role of twist as a regulator of muscle development had been well-established in fruit flies by several groups, including our own, but the functions of the mammalian gene were not known," says Olson. "We assumed it would play a role similar to the fruit fly gene in...