From the 2000 Holiday Lectures — Clockwork Genes: Discoveries in Biological Time

The Drosophila Molecular Clock Model

Watch these animations display the dynamic orchestration of the molecular events of the Drosophila biological clock.

7 minutes 34 seconds

The Human Suprachiasmatic Nucleus

In mammals, the controlling clock component that generates a 24-hour rhythm is the suprachiasmatic nucleus (SCN), located in a part of the brain called the hypothalamus. The SCN produces a signal that can keep the rest of the body on an approximately 24-hour schedule. This animation illustrates the location of the SCN in the human brain.

1 minute 40 seconds

The Mammalian Molecular Clock Model

This animation shows the molecular interactions involved in the negative feedback loop responsible for circadian rhythms in mammals.

3 minutes 40 seconds

Measuring Circadian Activity in Drosophila

This animation series shows four experiments that compare the activity patterns of a wild-type fly keeping a normal schedule with those of a mutant fly apparently following a 19-hour internal clock.

2 minutes 2 seconds