( eir usual maneuvers. The gender-b...)Fighting like a girl or boy determined by gene in fruit flies

The gender-bending fruit flies were first developed to study courtship in the Austrian lab of co-author Barry Dickson, director of the Institute of Molecular Pathology. Dickson created male flies with the female version of the gene and female flies with the male version.

In Dickson's courtship studies, male fruit flies with the female fruitless gene were not acting like males, but it wasn't clear that they were acting like females, either. (Ultimately, courtship behavior is constrained by pheromones and anatomy, which do not change.) He contacted Kravitz, hoping that aggression studies would resolve the lingering question of male behavior changes.

Meanwhile, co-author Steven Nilsen, a postdoctoral fellow in Kravitz's lab, had similar questions and was staging contests between another line of mutant fruitless flies without such clear brain-switching genetics. So Austrian postdoctoral fellow Eleftheria Vrontou, the lead author, packed up their flies and took them to the Boston fruit fly fight club.

For the past five years, researchers in Kravitz's lab have been methodically scoring fruit fly fights to determine the normal aggression patterns with the long-term goal of documenting how genes and molecules change those patterns. They stage male fights on bottle-cap-sized food cups decorated with a headless female (a live female will fly away, leaving males nothing to fight over). Female flies fight over an extra dab of fresh yeast paste ?their version of dark chocolate, Kravitz said. The flies are videotaped. The movies are replayed in slow motion to record each move and countermove.

"Ed has systematically developed reproducibly aggressive behavior in flies and paved the way for serious analysis," said Laurie Tompkins, program director at the National Institute of General Medical Sciences, which funds the work. The fruit fly aggression model is part of a new trend to use fruit flies as models to st
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Source:Harvard Medical School