DCRY is a <i>Drosophila </i>photoreceptor protein implicated in light entrainment of circadian rhythm

Ishikawa, Tomoko; Matsumoto, Akira; Kato, Tomohisa; Togashi, Shin; Ryo, Haruko; Ikenaga, Mituo; Todo, Tomoki; Ueda, Ryo; Tanimura, Teiichi

doi:10.1046/j.1365-2443.1999.00237.x

Cited by 75 publications

(49 citation statements)

References 29 publications

(35 reference statements)

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“…Canton-S was used as WT. The following mutants and transgenic strains were used: per 01 (49). All experiments were performed at 25°C, with exceptional cases described separately.…”

Section: Methodsmentioning

confidence: 99%

Peripheral circadian clock for the cuticle deposition rhythm in Drosophila melanogaster

Ito

Goto

Shiga

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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Insect endocuticle thickens after adult emergence by daily alternating deposition of two chitin layers with different orientation. Although the cuticle deposition rhythm is known to be controlled by a circadian clock in many insects, the site of the driving clock, the photoreceptor for entrainment, and the oscillatory mechanism remain elusive. Here, we show that the cuticle deposition rhythm is regulated by a peripheral oscillator in the epidermis in Drosophila melanogaster. Free-running and entrainment experiments in vitro reveal that the oscillator for the cuticle deposition rhythm is independent of the central clock in the brain driving the locomotor rhythms. The cuticle deposition rhythm is absent in null and dominant-negative mutants of clock genes (i.e., period, timeless, cycle, and Clock), indicating that this oscillator is composed of the same clock genes as the central clock. Entrainment experiments with monochromatic light-dark cycles and cry b flies reveal that a blue light-absorbing photoreceptor, cryptochrome (CRY), acts as a photoreceptor pigment for the entrainment of the cuticle deposition rhythm. Unlike other peripheral rhythms in D. melanogaster, the cuticle deposition rhythm persisted in cry b and cry OUT mutant flies, indicating that CRY does not play a core role in the rhythm generation in the epidermal oscillator.circadian rhythm ͉ clock genes ͉ cryptochrome ͉ entrainment ͉ epidermal cell C ircadian clocks control daily rhythms at the molecular, physiological, and behavioral levels. Like most organisms, the central circadian oscillator controlling the locomotor activity rhythm in Drosophila is proposed to consist of molecular feedback loops. The feedback loops comprise several core clock genes, such as period (per), timeless (tim), Clock (Clk), and cycle (cyc) (1). These genes encode PER, TIM, CLK, and CYC proteins, respectively, and loss-of-function or dominant-negative mutations in these genes result in loss of normal circadian rhythmicity (2-5). CLK and CYC form a heterodimer to activate transcription of per and tim (2, 4, 6). PER and TIM form another heterodimer, are transferred into the nucleus, and then inactivate the transcriptional activity of the CLK/CYC heterodimer (6). The feedback loops are entrained and reset by the lightinduced degradation of TIM mediated by a photoreceptor pigment, cryptochrome (CRY) (7-10).In addition to the central oscillator, peripheral oscillators exist in many tissues, including the compound eyes, antennae, wings, legs, and Malpighian tubules in adults and the ring gland in pupae (11)(12)(13)(14). These oscillators are self-sustained and directly light-entrainable even in vitro (11-13). In addition, the oscillators are clearly independent of the central circadian oscillator(s) in the brain (15, 16). Previous reports revealed that the peripheral oscillator shares the same genes with the central clock in the brain (12, 17). However, there is a remarkable difference that, in the peripheral oscillator, CRY functions as a core component besides a photorecepto...

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“…Canton-S was used as WT. The following mutants and transgenic strains were used: per 01 (49). All experiments were performed at 25°C, with exceptional cases described separately.…”

Section: Methodsmentioning

confidence: 99%

Peripheral circadian clock for the cuticle deposition rhythm in Drosophila melanogaster

Ito

Goto

Shiga

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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“…The Drosophila cryptochrome has been characterized in some detail. There is only one cryptochrome gene in Drosophila and it is clearly involved in circadian photoreception (153,156,157). However, it is unclear at present whether photic input into the circadian clock comes from the visual photoreceptor system (i.e.…”

Section: Cryptochrome Genetics In Other Animalsmentioning

confidence: 99%

Cryptochrome: The Second Photoactive Pigment in the Eye and Its Role in Circadian Photoreception

Sancar

2000

Annu. Rev. Biochem.

243

201

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Key Words blue-light photoreceptor, flavoprotein, retina, suprachiasmatic nucleus, circadian blind mice, seasonal affective disorder s Abstract Circadian rhythms are oscillations in the biochemical, physiological, and behavioral functions of organisms that occur with a periodicity of approximately 24 h. They are generated by a molecular clock that is synchronized with the solar day by environmental photic input. The cryptochromes are the mammalian circadian photoreceptors. They absorb light and transmit the electromagnetic signal to the molecular clock using a pterin and flavin adenine dinucleotide (FAD) as chromophore/cofactors, and are evolutionarily conserved and structurally related to the DNA repair enzyme photolyase. Humans and mice have two cryptochrome genes, CRY1 and CRY2, that are differentially expressed in the retina relative to the opsin-based visual photoreceptors. CRY1 is highly expressed with circadian periodicity in the mammalian circadian pacemaker, the suprachiasmatic nucleus (SCN). Mutant mice lacking either Cry1 or Cry2 have impaired light induction of the clock gene mPer1 and have abnormally short or long intrinsic periods, respectively. The double mutant has normal vision but is defective in mPer1 induction by light and lacks molecular and behavioral rhythmicity in constant darkness. Thus, cryptochromes are photoreceptors and central components of the molecular clock. Genetic evidence also shows that cryptochromes are circadian photoreceptors in Drosophila and Arabidopsis, raising the possibility that they may be universal circadian photoreceptors. Research on cryptochromes may provide new understanding of human diseases such as seasonal affective disorder and delayed sleep phase syndrome. CONTENTS

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“…Cashmore, 1997Cashmore, , 1998Somers et al, 1998) and more recently for mammals, Drosophila (dCRY), and other organisms (e.g. Emery et al, 1998;Stanewsky et al, 1998;Cashmore et al, 1999;Ceriani et al, 1999;Egan et al, 1999;Ishikawa et al, 1999;Selby & Sancar, 1999;Hall, 2000;Sancar, 2000;Ivanchenko et al, 2001). Cryp tochrome has a chromophore based on vitamin B2, with (in Drosophila) pterin light-harvesting and flavin cata lytic cofactors, and is sensitive to blue and UV-A light.…”

Section: Inputsmentioning

confidence: 99%

Studying insect photoperiodism and rhythmicity: Components, approaches and lessons

Danks¹

2003

Eur. J. Entomol.

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Abstract.Components of daily and seasonal timing systems in insects are reviewed. Photoperiod indicates seasonal position reliably, but signals can be much modified by habitat, latitude and season. Several receptor features and pigment systems are known, with different daily, seasonal and general functions, including differences between circadian and seasonal reception. Clocks can serve several different purposes, functioning as daily oscillators, interval timers or through successive requirements. The molecular functioning of circadian clocks is best known, but even so there is considerable complexity and diversity and much remains to be discovered. We know relatively little about the internal states that provide information for timed responses (such as the photoperi odic "counter"), about the central controlling mechanism, or about the effectors that transmit output signals. Nevertheless, temporal responses serve a very great range of purposes in insects, and the reported complexity in all of the components of timing systems reflects complex ecological needs across daily and seasonal intervals. The variety of components and the complexity of interactions reported (even within species), as well as the diversity of such elements as photosensitive pigments, molecular clock function and potential neurotransmitters, suggests that -unlike some earlier expectations -there is no single master clock for all timing functions in insects.Insect photoperiodism and rhythmicity have been studied by both observational or direct approaches (examination of system ele ments or devices, and qualities such as survival), and by inferential or indirect approaches (such as interpretation of various responses to photoperiod, modelling, and estimating fitness). Many students work with only one approach, but the power of different approaches is not equal, and knowledge at one level may not give answers at another. These difficulties tend to limit our under standing of the linkages among components.This overview suggests several lessons for the study of photoperiodism and rhythmicity. There are multiple elements, complex integration and a diversity of clocks, showing that different processes serve different purposes. The diversity of findings also results from the fact that different investigative approaches, which depend on the question being asked and on the perspective of the investi gator, can influence the outcome of the investigation. Given these complexities, I believe that the key to interpreting photoperiodic and circadian responses is their ecological value. Notwithstanding the interest of timing mechanisms or their parts and of specific responses, daily rhythms and seasonal timing are best understood through the essential context provided by the ecological demands on the actual organisms under study.

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DCRY is a Drosophila photoreceptor protein implicated in light entrainment of circadian rhythm

Cited by 75 publications

References 29 publications

Peripheral circadian clock for the cuticle deposition rhythm in Drosophila melanogaster

Peripheral circadian clock for the cuticle deposition rhythm in Drosophila melanogaster

Cryptochrome: The Second Photoactive Pigment in the Eye and Its Role in Circadian Photoreception

Studying insect photoperiodism and rhythmicity: Components, approaches and lessons

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