"I like to say that flies sleep similarly to humans, except flies don't use pillows," said Allada, who also is associate director for Northwestern's Center for Sleep and Circadian Biology. The biological timing mechanism for all animals comes from a common ancestor hundreds of millions of years ago.
Ataxin-2 is the second gene in a little more than two years that Northwestern researchers have identified as a core gear of the circadian clock, and the two genes play similar roles.
Allada, Lim and colleagues in 2011 reported their discovery of a gene, which they dubbed "twenty-four," that plays a role in translating the PER protein, keeping the sleep-wake cycle on a 24-hour rhythm.
Allada and Lim wanted to better understand how twenty-four works, so they looked at proteins that associate with twenty-four. They found the twenty-four protein sticking to ATAXIN-2 and decided to investigate further. In their experiments, reported in Science, Allada and Lim discovered the Ataxin-2 and twenty-four genes appear to be partners in PER protein translation.
"We've really started to define a pathway that regulates the circadian clock and seems to be especially important in a specific group of neurons that governs the fly's morning wake-up," Allada said. "We saw that the molecular and behavioral consequences of losing Ataxin-2 are nearly the same as losing twenty-four."
As is the case in a mutation of the twenty-four gene, when the Ataxin-2 gene is not present, very little PER protein is found in the circadian pacemaker neurons of the brain, and the fly's sleep-wake rhythm is disturbed.
|Contact: Megan Fellman|