Alexander Schier’s transparent fish are helping him understand the basic secrets of human development: how early embryonic cells communicate so that some develop into heart tissue, some into brain cells, and others into tissues that form the rest of the body.
Zebrafish, though striped as adults, are transparent when embryos, making them attractive to researchers because scientists can literally look inside them and watch how they develop.
Schier is using his fish model to investigate the phenomenon of sleep. Though all of us do it, nobody really understands why. The need for sleep varies widely in the animal kingdom, but science hasn’t yet figured out why shutting down our waking consciousness for such a large part of every day is so crucial to our well-being.
Schier suspects the need for sleep is linked to repair and restoration and makes us more ready to face the challenges of the coming day.
Schier and members of his lab are observing the fish’s behavior. The fish are active for 14 hours per day and go through the zebrafish equivalent of sleep, where their activity is reduced and responses to stimuli slowed, for 10 hours.
Researchers are first observing the fish’s normal sleeping behavior and keeping an eye out for mutants – fish who either sleep more or less than others. Once the mutants are identified, the investigation will turn to the genetic code of those fish, where researchers will look for genes that are different from those of “normal” fish.
“We don’t really know why we have to sleep, why animals have to rest,” Schier said. “[Sleep regulation] is a major question in human health.”