Circadian regulation of gene expression systems in the Drosophila head

Mechanisms composing Drosophila's clock are conserved within the animal kin gdom. To learn how such clocks influence behavioral and physiological rhyth ms, we determined the complement of circadian transcripts in adult Drosophi la heads. High-density oligonucleotide arrays were used to collect data in the form of three 12-point time course experiments spanning a total of 6 da ys. Analyses of 24 hr Fourier components of the expression patterns reveale d significant oscillations for similar to 400 transcripts. Based on seconda ry filters and experimental verifications, a subset of 158 genes showed par ticularly robust cycling and many oscillatory phases. Circadian expression was associated with genes involved in diverse biological processes, includi ng learning and memory/synapse function, vision, olfaction, locomotion, det oxification, and areas of metabolism. Data collected from three different c lock mutants (per(o), tim(o1), and Clk(Jrk)), are consistent with both know n and novel regulatory mechanisms controlling circadian transcription.