Scientists discover a gene that regulates napping during the day

Researchers at Rutgers University have identified a nap-suppressing gene in fruit flies. The discovery is providing experts with new insight into how humans and other animals weigh the benefits of a nap versus important things that need to be done during the day.

According to the researchers, midday naps are more intense on hotter days, which is a phenomenon that likely evolved to help protect against exposure to the intense afternoon sun.

Short naps are known to have cognitive benefits in humans, including help with memory and learning. On the other hand, excessive daytime sleep has been linked to serious diseases such as Parkinson’s and diabetes.

The researchers have pinpointed a gene in Drosophila flies, which they refer to as the “daywake” gene, that suppresses the inclination to take a daytime nap when temperatures are cool. This gene is likely activated to increase the amount of time that the fruit flies use to focus on hunting for food and mates.

“This gene contributes to behavioral flexibility, or the ability to hide from the noontime sun when the weather is hot but engage in activities good for survival when the weather is cool. That probably helped these flies expand beyond their ancestral home in equatorial Africa to successfully colonize temperate zones around the world,” explained study co-author Professor Isaac Edery.

The daywake gene slightly overlaps a “period” gene that is known to regulate circadian rhythm and daily wake-sleep cycles in the files. The researchers found that daywake activity is increased by a specific sequence within the period gene, and that this process is most effective when the flies are exposed to cold temperatures.

“Although the daywake gene is not present in humans, our finding reinforces the idea that nighttime sleep and daytime siesta are governed by distinct mechanisms and serve separate functions for health and survival,” said Professor Edery.

The finding that the activities of a sequence in one gene can trigger the action of a nearby gene is a new discovery in itself which promises to reveal new gene regulatory mechanisms in flies and other organisms, concluded Professor Edery.

The study is published in the journal Current Biology.

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By Chrissy Sexton, Earth.com Staff Writer