PROVIDENCE, R.I. -- Male fruit flies are smaller and darker than female flies. The hair-like bristles on their forelegs are shorter, thicker. Their sexual equipment, of course, is different, too.

"Doublesex" is the gene largely responsible for these body differences. Doublesex, new research shows, is responsible for behavior differences as well. The finding, made by Brown University biologists, debunks the notion that sexual mind and sexual body are built by separate sets of genes. Rather, researchers found, doublesex acts in concert with the gene "fruitless" to establish the wing-shaking come-ons and flirtatious flights that mark male and female fly courtship.

Results are published in Nature Genetics.

"What we found here, and what is becoming increasingly clear in the field, is that genetic interactions that influence behavior are more complex than we thought," said Michael McKeown, a Brown biologist who led the research. "In the case of sex-differences in flies, there isn't a simple two-track genetic system one that shapes body and one that shapes behavior. Doublesex and fruitless act together to help regulate behavior in the context of other developmental genes."

How genes contribute to behavior, from aggression to alcoholism, is a growing and contentious area of biology. For more than a decade, McKeown has been steeped in the science, using the fruit fly as a model to understand how genes build a nervous system that, in turn, controls complex behaviors. Since humans and flies have thousands of genes in common, the work can shine a light on the biological roots of human behavior. For example, McKeown recently helped discover a genetic mutation that causes flies to develop symptoms similar to Alzheimer's disease a gene very similar to one found in humans.

Some of McKeown's recent work focuses on understanding gene networks that control sexual behavior. Research on the topic is often contradictory. Some scienti
'"/>

Contact: Wendy Lawton
Wendy_Lawton@brown.edu
401-863-1862
Brown University
30-Nov-2006