Drosophila rhythms: From brain to behavior

The period (per) gene and the timeless (tim) gene are essential components of the circadian clock in Drosophila melanogaster. Both gene products interact in interdependent feedback loops, producing- a self-sustained cellular rhythm in situ. Several oscillating cells are combined to discrete pacemaker centers that control rhythmic behavior. This paper reviews the work on localizing the circadian pacemaker neurons controlling activity and eclosion, leading to questions about how these pacemaker cells are synchronized to the external light-dark cycle, and how they impose periodicity on behavior The circadian system of Drosophila is also compared with that of other arthropods. (C) 1996 Academic Press Ltd.