Journal ArticleDOI
A new role for cryptochrome in a Drosophila circadian oscillator
Balaji Krishnan,Joel D. Levine,M. Kathlea S. Lynch,Harold B. Dowse,Pablo Funes,Jeffrey C. Hall,Paul E. Hardin,Stuart E. Dryer +7 more
TLDR
It is shown that CRY contributes to oscillator function and physiological output rhythms in the antenna during and after entrainment to light–dark cycles and after photic input is eliminated by entraining flies to temperature cycles, indicating fundamental differences between central and peripheral oscillator mechanisms in Drosophila.Abstract:
Cryptochromes are flavin/pterin-containing proteins that are involved in circadian clock function in Drosophila and mice. In mice, the cryptochromes Cry1 and Cry2 are integral components of the circadian oscillator within the brain and contribute to circadian photoreception in the retina. In Drosophila, cryptochrome (CRY) acts as a photoreceptor that mediates light input to circadian oscillators in both brain and peripheral tissue. A Drosophila cry mutant, cryb, leaves circadian oscillator function intact in central circadian pacemaker neurons but renders peripheral circadian oscillators largely arrhythmic. Although this arrhythmicity could be caused by a loss of light entrainment, it is also consistent with a role for CRY in the oscillator. A peripheral oscillator drives circadian olfactory responses in Drosophila antennae. Here we show that CRY contributes to oscillator function and physiological output rhythms in the antenna during and after entrainment to light-dark cycles and after photic input is eliminated by entraining flies to temperature cycles. These results demonstrate a photoreceptor-independent role for CRY in the periphery and imply fundamental differences between central and peripheral oscillator mechanisms in Drosophila.read more
Citations
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Journal ArticleDOI
Time zones: a comparative genetics of circadian clocks.
Michael W. Young,Steve A. Kay +1 more
TL;DR: The circadian clock is a widespread cellular mechanism that underlies diverse rhythmic functions in organisms from bacteria and fungi, to plants and animals, and the weight of evidence favours their independent evolutionary origins in different kingdoms.
Journal ArticleDOI
Circadian rhythms from flies to human
TL;DR: The existence of a circadian clock in humans had been postulated for decades, but an understanding of the molecular mechanisms has required the full complement of research tools, and researchers turned to genetically tractable model organisms such as Drosophila.
Journal ArticleDOI
The Cryptochromes: Blue Light Photoreceptors in Plants and Animals
Inês Chaves,Richard Pokorny,Martin Byrdin,Nathalie Hoang,Thorsten Ritz,Klaus Brettel,Lars-Oliver Essen,Gijsbertus T. J. van der Horst,Alfred Batschauer,Margaret Ahmad +9 more
TL;DR: The structural, photochemical, and molecular properties of cry-DASH, plant, and animal cryptochromes are reviewed in relation to biological signaling mechanisms and common features that may contribute to better understanding the function of cryptochromaes in diverse systems including in man are uncovered.
Journal ArticleDOI
Intercellular Coupling Confers Robustness against Mutations in the SCN Circadian Clock Network
Andrew C. Liu,Andrew C. Liu,David K. Welsh,David K. Welsh,David K. Welsh,Caroline H. Ko,Caroline H. Ko,Hien G. Tran,Hien G. Tran,Eric E. Zhang,Eric E. Zhang,Aaron A. Priest,Ethan D. Buhr,Oded Singer,Kirsten Meeker,Inder M. Verma,Francis J. Doyle,Joseph S. Takahashi,Joseph S. Takahashi,Steve A. Kay +19 more
TL;DR: These studies reveal previously unappreciated requirements for Per1, Per2, and Cry1 in sustaining cellular circadian rhythmicity and demonstrate that SCN intercellular coupling is essential not only to synchronize component cellular oscillators but also for robustness against genetic perturbations.
Journal ArticleDOI
Rhythms of mammalian body temperature can sustain peripheral circadian clocks.
TL;DR: It is postulate that both endogenous and environmental temperature cycles can participate in the synchronization of peripheral clocks in mammals.
References
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Journal ArticleDOI
mCRY1 and mCRY2 are essential components of the negative limb of the circadian clock feedback loop.
Kazuhiko Kume,Mark J. Zylka,Sathyanarayanan Sriram,Lauren P. Shearman,David R. Weaver,Xiaowei Jin,Elizabeth S. Maywood,Michael H. Hastings,Steven M. Reppert +8 more
TL;DR: It is determined that two mouse cryptochrome genes, mCry1 and mCry2, act in the negative limb of the clock feedback loop, and the mPER and mCRY proteins appear to inhibit the transcriptional complex differentially.
Journal ArticleDOI
Interacting Molecular Loops in the Mammalian Circadian Clock
Lauren P. Shearman,Sathyanarayanan Sriram,David R. Weaver,Elizabeth S. Maywood,Inẽs Chaves,Binhai Zheng,Kazuhiko Kume,Cheng Chi Lee,Gijsbertus T. J. van der,Horst,Michael H. Hastings,Steven M. Reppert +11 more
TL;DR: Analysis of Clock/Clock mutant mice, homozygous Period2(Brdm1) mutants, and Cryptochrome-deficient mice reveals substantially altered Bmal1 rhythms, consistent with a dominant role of PERIOD2 in the positive regulation of the Bmal 1 loop.
Journal ArticleDOI
Mammalian Cry1 and Cry2 are essential for maintenance of circadian rhythms.
Gijsbertus T. J. van der Horst,Manja Muijtjens,Kumiko Kobayashi,Riya Takano,Shin Ichiro Kanno,Masashi Takao,Jan de Wit,Anton Verkerk,André P. M. Eker,Dik van Leenen,Ruud M. Buijs,Dirk Bootsma,Jan H.J. Hoeijmakers,Akira Yasui +13 more
TL;DR: It is shown that mice lacking the Cry1 or Cry2 protein display accelerated and delayed free-running periodicity of locomotor activity, respectively, which suggests that, in addition to a possible photoreceptor and antagonistic clock-adjusting function, both proteins are essential for the maintenance of circadian rhythmicity.
Book
The analysis of time series
TL;DR: The analysis of time series shows improvements in the quality of the data over time, particularly in the case of discrete-time series data.
Journal ArticleDOI
The cryb mutation identifies cryptochrome as a circadian photoreceptor in Drosophila
Ralf Stanewsky,Maki Kaneko,Patrick Emery,Bonnie Beretta,Karen Wager-Smith,Steve A. Kay,Michael Rosbash,Michael Rosbash,Jeffrey C. Hall +8 more
TL;DR: Cryb flies are rhythmic in constant darkness, correlating with robust PER and TIM cycling in certain pacemaker neurons, and is an apparent null mutation in a gene encoding Drosophila's version of the blue light receptor cryptochrome.