The 2006 Pittendrigh/Aschoff Lecture: New Roles for Old Proteins in the Drosophila Circadian Clock.

Circadian behaviors in the animal kingdom are regulated by a small set of conserved genes. Starting with a historical perspective focused on Drosophila, the authors describe how the recurrent discovery of circadian clock genes uncovered a molecular mechanism associated with cycling gene expression. These molecular cycles appear to emerge from delayed negative and positive feedback. The authors will then introduce a novel timing mechanism uncovered by a single cell-based assay, with the new ideas and prospects for future research that it has raised. [ABSTRACT FROM AUTHOR]