Monarch butterflies have unique circadian clocks (see related story), which regulate daily events—like sleep and hunger—and help the insects use the sun as a compass, said Steven Reppert, a University of Massachusetts neurobiologist who led the study published online Tuesday in the PLoS Biology Journal.
The researchers genetically mapped the molecular underpinnings of the butterflies' circadian clocks and found cryptochrome proteins that are common in both insects and mammals.
Reppert believes these proteins enable the monarchs to navigate by using the sun's position in the sky.
(Related story: Moonlight Triggers Mass Coral "Romance" [October 22, 2007])
"A butterfly's brain is no bigger than the head of a pin, and yet it has this incredible capability. So we really want to understand that," Reppert said.
What It Means
When understood completely, the find might help shed light on the biological clocks of humans, and in turn aid research into everything from sleep disorders to depression.
Lincoln Brower, a monarch expert at the University of Florida and Sweet Briar College in Sweet Briar, Virginia, said the discovery was significant because it shows that "studying the monarch butterfly is producing crucial information about the nature of life."
The research was funded in part by grants from the National Institutes of Health and the Czech Republic's Ministry of Education, Youth, and Sports.
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