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The mechanisms by which circadian pacemaker systems transmit timing information to control behavior are largely unknown. Here, we define two critical features of that mechanism in Drosophila. We first describe animals mutant for the pdf neuropeptide gene, which is expressed by most of the candidate pacemakers (LNv neurons). Next, we describe animals in(More)
Biochemical studies indicate that the Drosophila timeless protein (Tim) is a stoichiometric partner of the period protein (Per) in fly head extracts. A Per-Tim heterodimeric complex explains the reciprocal autoregulation of the proteins on transcription. The complex is under clock control, and many circadian features of the Tim cycle resemble those of the(More)
A new rhythm mutation was isolated based on its elimination of per-controlled luciferase cycling. Levels of period or timeless clock gene products in the mutant are flat in daily light-dark cycles or constant darkness (although PER and TIM oscillate normally in temperature cycles). Consistent with the fact that light normally suppresses TIM, cryb is an(More)
We report the identification, characterization, and cloning of a novel Drosophila circadian rhythm gene, dClock. The mutant, initially called Jrk, manifests dominant effects: heterozygous flies have a period alteration and half are arrhythmic, while homozygous flies are uniformly arrhythmic. Furthermore, these flies express low levels of the two clock(More)
Daily rhythms of physiology and behaviour are precisely timed by an endogenous circadian clock. These include separate bouts of morning and evening activity, characteristic of Drosophila melanogaster and many other taxa, including mammals. Whereas multiple oscillators have long been proposed to orchestrate such complex behavioural programmes, their nature(More)
Mutations in the period (per) gene of Drosophila melanogaster affect both circadian and ultradian rhythms. Levels of per gene product undergo circadian oscillation, and it is now shown that there is an underlying oscillation in the level of per RNA. The observations indicate that the cycling of per-encoded protein could result from per RNA cycling, and that(More)
Daily sleep cycles in humans are driven by a complex circuit within which GABAergic sleep-promoting neurons oppose arousal. Drosophila sleep has recently been shown to be controlled by GABA, which acts on unknown cells expressing the Rdl GABAA receptor. We identify here the relevant Rdl-containing cells as PDF-expressing small and large ventral lateral(More)
The period gene (per) is required for Drosophila melanogaster to manifest circadian (congruent to 24 hr) rhythms. We report here that per protein (PER) undergoes daily oscillations in apparent molecular mass as well as abundance. The mobility changes are largely or exclusively due to multiple phosphorylation events. The temporal profile of the classic(More)
Polyclonal antibodies were prepared against the period gene product, which influences biological rhythms in D. melanogaster, by using small synthetic peptides from the per sequence as immunogens. The peptide that elicited the best antibody reagent was a small domain near the site of the pers (short period) mutation. Specific immunohistochemical staining was(More)
When the protein encoded by the period (per) gene, which influences circadian rhythms in Drosophila melanogaster, was labeled with an anti-per antibody in adult flies sectioned at different times of day, regular fluctuations in the intensity of immunoreactivity were observed in cells of the visual system and central brain. These fluctuations persisted in(More)