Tick, Tock the Biological Clock

Dateline: 06/25/98

We are all familiar with the "biological clock." Some of us are morning people; some are night people; and some are ... well, we'll leave that for another time. Regardless of our preferences, we are all governed by a biological clock with an approximate cycle of 24 hours corresponding to the Earth's rotation time. Biologically speaking, this molecular clock is known as the circadian rhythm. Researchers at Northwestern University have recently discovered remarkable similarities in the main components of clocks across organisms--from invertebrates to mammals.

This is the first study to show these similarities in circadian rhythm mechanisms. Researchers found that the same gene, dubbed the clock gene, has the same function in both flies and mice. Three clock genes in particular are the same across the different organisms and seem to form the basis for the rudimentary clock system that has been preserved.

The genes work by a feedback loop of both activation and inhibition forming the rudimentary system. Like the oscillation of a pendulum, the process can "swing" back and forth and, in turn, regulate whether the clock is "on" or "off." This loop seems to be the basis of the system in animals.

Circadian rhythms regulate a variety of activities (such as the morning and night people mentioned above). The rhythms contribute to such things as jet lag and many sleep disorders.

Scientists hope that by studying the underlying mechanism, they will be able to predict why certain anomalies occur at particular times of the day, for instance why people seem to be more prone to heart attacks in the early morning versus later in the day.

What do you think? Come over to the Biology Forum and share your thoughts, opinions, and feelings. 'Til next time...

For additional information see:
Mammal Clock Gene - Access Excellence