Fruity Flies

A new study finds that both drugs and genetic manipulation can turn the homosexual behavior of fruit flies on and off within a matter of hours.

In fact, homosexuality in the fruit flies seems to be regulated by how they interpret the scent of another.

Homosexuality is widespread in the animal world. But scientists have long debated whether, in humans a "gay gene" exists.

In the new work, University of Illinois at Chicago researcher David Featherstone and coworkers discovered a gene in fruit flies they call "genderblind," or GB. A mutation in GB turns flies bisexual.

Post-doctoral researcher Yael Grosjean found that all male fruit flies with a mutation in their GB gene courted other males.

"It was very dramatic," Featherstone said. "The GB mutant males treated other males exactly the same way normal male flies would treat a female. They even attempted copulation."

To test this, the researchers genetically altered synapse strength, independent of GB. They also gave flies drugs to alter synapse strength. As predicted, they were able to turn fly homosexuality on and off, within hours.