A team of scientists named the sleep-inducing gene that discovered "nemuri," which is the Japanese word for "sleep."
The team, led by Japanese researcher Hirofumi Toda of the University of Pennsylvania, discovered the gene through experiments with fruit flies. The finding was published in the Friday issue of the American journal Science.
Scientists say overexpression of the gene has made fruit flies last longer, while flies woke up easily and had difficulty falling asleep when the gene mutated.
They also found that the gene increased the ability of flies to survive bacterial infection, leading them to believe that the gene plays a role in the immune system.
They think the gene triggers sleep when the body is under stress, such as sleep deprivation or bacterial infection.
The gene has not yet been detected in humans. But Toda points out that people with colds tend to sleep more, which leads to recovery. He says that the same type of mechanism observed in fruit flies may also be at work in humans.