The proposed research described in this application is concerned with understanding the chemical machinery that underlies 24-hour (circadian) cycles. Circadian cycles are common in the plant and animal kingdom and organize a number of important processes including sleep and waking in humans. The biochemical mechanisms that generate such a long cycle are not known. The investigations will use a model system, the eye of a marine mollusc Aplysia. This eye has all the machinery for expressing many cycles of a circadian rhythm of nerve impulse frequency, under constant conditions of darkness and temperature, when isolated from the rest of the animal. The principal investigator will use biochemical and physiological methods to generate data about the mechanisms of this neuronal circadian cycle. The major approach will be to study the timing of appearance of particular proteins during the circadian cycle. From the amino acid sequence of these proteins the principal investigator will synthesize oligonucleotide probes which can be used to clone the gene messages that code for these proteins. These studies will begin to us what genes and proteins are being expressed specifically during the circadian cycle.
