The contribution of Drosophila Clk to rhythmic photoreceptor gene expression

To better understand the role of the core circadian clock in photoreceptors, we generated a fly line null for the circadian transcription factor Clk (Clk[Jrk]) that expresses GFP on outer photoreceptor nuclei. We collected outer photoreceptor nuclei across the day and night in both control and Clk null flies to determine the number of genes in outer photoreceptors that require an intact molecular clock for their rhythmic expression.