Daily briefing: Gene-activity ‘clock’ predicts biological ageing

You have full access to this article via your institution. Hello Nature readers, would you like to get this Briefing in your inbox free every day? Sign up here . Zebrafish’s bodies are transparent for their first few weeks of life, which gave researchers a window into the fish’s brains while they slept. (WireStock via Alamy) Zebrafish ( Danio spp.) sleep in different stages that resemble the ‘cycles’ of sleep described in people. By tracking the eye movements of snoozing fish, researchers identified four ‘substates’ of sleep — three associated with nighttime slumber and one with short naps during the day . Identifying these distinct sleep states could help researchers to untangle what purpose they serve in fish and other animals. “It’s like a lot of things in biology: The more we look under the hood, the more complex it is,” says marine ecologist Michael Heithaus. The New York Times | 3 min read Reference: Nature Communications paper A powerful molecular clock calibrated using gene-activity data can predict biological ageing in rodents, monkeys and humans — and time to death in people . Although it isn’t ready for medical use, the tool could eventually be a boon to biologists keen to learn which drugs or lifestyle changes might mitigate ageing’s myriad effects on the body. …