Nearly all living things have a natural rhythm that influences their behavior and physiology. This rhythm typically is "circadian", following a near 24-hour cycle. Driven by an internal clock, a creature's natural rhythm is synchronized to the outside world by external cues, like the sun. So far, the products of eight different genes have been discovered to be essential to the operations of this clock. Scientists believe that these genes, in turn, somehow influence the expression of other genes throughout the body in order to control the timing of behaviors like sleep and wakefulness.

Researchers from three laboratories at the School of Medicine, in collaboration with a team at Affymetrix, have identified 22 genes that appear to be rhythmically regulated by the internal clock of the Drosophila fly and found hundreds more genes that are regulated by both light and the internal clock. The study appears in the June 24 issue of the Proceedings of the National Academy of Sciences.

"Understanding how our internal environment responds to our innate biological clock could help us develop better ways of adjusting to challenging circumstances, like unusual work shifts or jet lag following a long journey," says lead investigator Paul H. Taghert, Ph.D., professor of anatomy and neurobiology.

The fruit fly Drosophila melanogaster is one of the most commonly studied organisms, particularly in the pursuit of understanding biological clocks. In the past, researchers only could estimate the number of genes affected by the eight clock genes. But now that the fly's genome has been fully sequenced, scientists can scrutinize nearly all of the animal's 14,000 genes.

The Washing
'"/>

Contact: Gila Z. Reckess
reckessg@msnotes.wustl.edu
314-286-0109
Washington University School of Medicine
24-Jun-2002