A Genetic Revolution Launched on the Backs of Fruit Flies

Alice Park's article What Good is Sleep? New Lessons from the Fruit Fly illustrates the ways scientist have used Drosophila melanogaster or as we know it, the fruit fly, to find out how we humans deal with things like aggression and sleep. Like humans fruit flies need sleep in order to keep from hitting a brain meltdown. "During waking hours, the brain keeps adding new information about its environment, forming new circuits and new connections in an ever thickening neural network," if it never gets any time to cool itself it crashes. In fruit flies and humans alike the brain takes time to regroup from a day of new things to remember, during this time "the brain actively prunes the neural network laid out during waking hours, trimming away weaker connections that haven't been used in a while or weren't strong enough to begin with. The stronger connections are believed to be filed during sleep into long-term memory, where they can be accessed again and again as needed." So you can think of sleep as a pressure release valve. So what do flies do to require them to have to sleep? They eat and mate. While it does not sound very complex, it certainly can be. When the female supply is low, male flies have to compete with one another for the right to mate. But females aren't just looking for any old guy (sound familiar?) they want males that'll be able to provide an adequate food supply for them and the kids. The guy flies are willing to go as far as box if it means they'll get the prize -- food or mate -- and they even tend to have their own fighting style. Male flies rear on their hind legs and lunge at thier opponents when fighting while females head-butt and shove. This information is not very new but Harvard University's Edward Kravitz has been "able to link Drosophila's sex-specific behaviors to genes." When Kravitz bred male flies with female fighting genes, they tended to head-but and shove like females and when he bred female flies with male fighting genes they began to do the more aggresive lunging. The next step in this process is to "see if these same genes appear in mammals' or even the human genome. Chances are good: the fruit-fly genome is made up of 14,000 genes, while the human genome contains 20,000." Because the fruit fly is such a simple organism, we can use our genetic tools to decode it, meaning it will be used for many years to come. You can view this article at (http://www.time.com/time/health/article/0,8599,1889099,00.html)

• Are there any other behaviors scientists have been able to decode in fruit flies?
• Have scientist tested these findings in more complex animals?