Scientists may have figured out how the fruit fly keeps its internal clock in sync with the 24-hour day, a finding that could eventually shed light on jet lag and other human problems.
Animals have biological clocks that control such things as the sleep-wake cycle. But left to themselves, the clocks tend to run fast or slow; there has to be a mechanism for adjusting the clock each day in accordance with the light and dark cycle outdoors.In Thursday's issue of the journal Nature, scientists report that a particular protein in the fruit fly brain disintegrates when flies are exposed to light. That could be key to resetting the fly's internal clock, they said.
The protein is called Tim because it is produced from a gene called "timeless." It's not known just how light leads to the protein's degradation, said one of the researchers, Michael Rosbash, an investigator at the Howard Hughes Medical Institute and a biology professor at Brandeis University in Waltham, Mass.
Tim binds to a second protein called Per, and these Tim-Per matchups appear to be an important part of the fly clock, researchers said. Once Tim is destroyed as a result of light exposure, Per falls apart, too.
Just how all of this relates to people is not clear, because neither Tim nor Per has been found in mammals, Rosbash said.
Joe Takahashi of Northwestern University, who studies clock genes in mice, said the behavior of clocks is remarkably similar across a wide range of plants and animals.
"It's our hope that if we understand something in the fly, it's going to ultimately tell us something important about how the clock in the human works also," Takahashi said.
That in turn might lead to better ways to treat human problems that come from problems with the clock, he said. They include jet lag and sleepiness that comes from working different shifts.