From sleep hogs to early birds, people have a wide range of shut-eye needs. Now researchers report in the journal Nature that they have identified a single gene in fruit flies that determines how much rest the creatures require. Because humans carry a similar gene, the findings may shed light on the mechanisms and functions of sleep.
The ability to get by on very little sleep is a trait that seems to run in families, suggesting it may have a genetic component. To test that idea, Giulio Tononi and his colleagues at the University of Wisconsin-Madison spent four years studying the slumber habits of thousands of fruit flies. They discovered a line of flies that slept a third as much as regular flies did without any impairment in their performance on a variety of tasks. Dubbed minisleepers, these flies did experience one drawback, however: they tended to die sooner than the control flies did.
Genetic analysis of the minisleep flies revealed that they had a single amino acid mutation on the Shaker gene, which regulates a potassium ion channel into cells. In flies with the mutation, formation of a functional ion channel is disrupted. Potassium channels affect electrical activity in neurons, among other things, and the results suggest that changes in the ion's concentration could affect sleep in humans. Remarks study co-author Chiara Cirelli: "This research offers the possibility of developing a new class of compounds that could affect potassium channels in the brain rather than other brain chemical systems targeted currently."