Why Fruit Flies (and People) Sleep Differently

Researchers look to the duration of sleep in fruit flies as a key to understanding the need of sleep in people.


Why do some people need more—or less—sleep than others do? Scientists from the National Heart, Lung, and Blood Institute say they have identified a group of genes that might help answer that question.

Using 13 generations of fruit flies bred to be long sleepers (18 hours a day) or short sleepers (3 hours a day), the researchers compared genetic data and identified 126 differences among 80 genes that seem to be associated with sleep duration. According to the researchers, the genetic differences were tied to several important developmental and cell signaling pathways, and some had known functions in brain development, learning, and memory.

The lifespans of the 2 groups of long and short sleepers did not differ from those of the flies with normal sleeping patterns. That suggests, the researchers say, that there are few physiologic consequences of being an extremely long or short sleeper.

The study is “an important step toward solving one of the biggest mysteries in biology: the need to sleep,” says study leader Susan Harbison, PhD. “The involvement of highly diverse biologic processes in sleep duration may help explain why the purpose of sleep has been so elusive.”

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