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Sharma PN, Sheeba V. Reorganization of circadian activity and the pacemaker circuit under novel light regimes. Proc Biol Sci 2024; 291:20241190. [PMID: 39043245 PMCID: PMC11265910 DOI: 10.1098/rspb.2024.1190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 06/19/2024] [Accepted: 07/02/2024] [Indexed: 07/25/2024] Open
Abstract
Many environmental features are cyclic, with predictable changes across the day, seasons and latitudes. Additionally, anthropogenic, artificial-light-induced changes in photoperiod or shiftwork-driven novel light/dark cycles also occur. Endogenous timekeepers or circadian clocks help organisms cope with such changes. The remarkable plasticity of clocks is evident in the waveforms of behavioural and molecular rhythms they govern. Despite detailed mechanistic insights into the functioning of the circadian clock, practical means to manipulate activity waveform are lacking. Previous studies using a nocturnal rodent model showed that novel light regimes caused locomotor activity to bifurcate such that mice showed two bouts of activity restricted to the dimly lit phases. Here, we explore the generalizability of these findings and leverage the genetic toolkit of Drosophila melanogaster to obtain mechanistic insights into this unique phenomenon. We find that dim scotopic illumination of specific durations induces circadian photoreceptor CRYPTOCHROME-dependent activity bifurcation in male flies. We show circadian reorganization of the pacemaker circuit, wherein the 'evening' neurons regulate the timing of both bouts of activity under novel light regimes. Our findings indicate that such environmental regimes can be exploited to design light cycles, which can ease the circadian waveform into synchronizing with challenging conditions.
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Affiliation(s)
- Pragya Niraj Sharma
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Vasu Sheeba
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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2
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Wang Y, Jin L, Belušič G, Beukeboom LW, Wertheim B, Hut RA. Circadian entrainment to red-light Zeitgebers and action spectrum for entrainment in the jewel wasp Nasonia vitripennis. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:459-472. [PMID: 37735210 PMCID: PMC11106113 DOI: 10.1007/s00359-023-01672-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/26/2023] [Accepted: 09/01/2023] [Indexed: 09/23/2023]
Abstract
Light is the most important environmental cue for the circadian system of most organisms to stay synchronized to daily environmental changes. Like many other insects, the wasp Nasonia vitripennis has trichromatic compound eye-based colour vision and is sensitive to the light spectrum ranging from UV to green. We recently described a red-sensitive, ocelli-based photoreceptor, but its contribution to circadian entrainment remains unclear. In this study, we investigated the possibility of Nasonia circadian light entrainment under long-wavelength red LED light-dark cycles and characterized the strength of red light as a potential Zeitgeber. Additionally, we measured the possibility of entrainment under various light intensities (from 5·1012 to 4·1015 photons·cm-2·s-1) and a broader range of wavelengths (455-656 nm) to construct corresponding action spectra for characterizing all circadian photoreceptors involved in photic entrainment. We also conducted electroretinogram (ERG) recordings for each wavelength in the compound eyes. Our findings demonstrate that Nasonia can entrain under red light dark cycles, and the sensory pathway underlying the red-light Zeitgeber response may reside in the ocelli. Combined with findings from previous research, we pose that blue- and green-sensitive rhodopsin photoreceptor cells function as the major circadian photoreceptors in both circadian entrainment by light-dark cycles and circadian phase shifts by light pulses, whereas the red-sensitive photoreceptor cell requires higher light intensity for its role in circadian entrainment by light-dark cycles.
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Affiliation(s)
- Yifan Wang
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, the Netherlands.
| | - Lijing Jin
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, the Netherlands
| | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Leo W Beukeboom
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, the Netherlands
| | - Bregje Wertheim
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, the Netherlands.
| | - Roelof A Hut
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, the Netherlands
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3
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Ajayi OM, Wynne NE, Chen SC, Vinauger C, Benoit JB. Sleep: An Essential and Understudied Process in the Biology of Blood-Feeding Arthropods. Integr Comp Biol 2023; 63:530-547. [PMID: 37429615 PMCID: PMC10503478 DOI: 10.1093/icb/icad097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 07/12/2023] Open
Abstract
Understanding the biology of blood-feeding arthropods is critical to managing them as vectors of etiological agents. Circadian rhythms act in the regulation of behavioral and physiological aspects such as blood feeding, immunity, and reproduction. However, the impact of sleep on these processes has been largely ignored in blood-feeding arthropods, but recent studies in mosquitoes show that sleep-like states directly impact host landing and blood feeding. Our focus in this review is on discussing the relationship between sleep and circadian rhythms in blood-feeding arthropods along with how unique aspects such as blood gluttony and dormancy can impact sleep-like states. We highlight that sleep-like states are likely to have profound impacts on vector-host interactions but will vary between lineages even though few direct studies have been conducted. A myriad of factors, such as artificial light, could directly impact the time and levels of sleep in blood-feeding arthropods and their roles as vectors. Lastly, we discuss underlying factors that make sleep studies in blood-feeding arthropods difficult and how these can be bypassed. As sleep is a critical factor in the fitness of animal systems, a lack of focus on sleep in blood-feeding arthropods represents a significant oversight in understanding their behavior and its role in pathogen transmission.
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Affiliation(s)
- Oluwaseun M Ajayi
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Nicole E Wynne
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Shyh-Chi Chen
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Clément Vinauger
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
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4
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Abhilash L, Shafer OT. Parametric effects of light acting via multiple photoreceptors contribute to circadian entrainment in Drosophila melanogaster. Proc Biol Sci 2023; 290:20230149. [PMID: 37700655 PMCID: PMC10498047 DOI: 10.1098/rspb.2023.0149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 08/21/2023] [Indexed: 09/14/2023] Open
Abstract
Circadian rhythms in physiology and behaviour have near 24 h periodicities that must adjust to the exact 24 h geophysical cycles on earth to ensure adaptive daily timing. Such adjustment is called entrainment. One major mode of entrainment is via the continuous modulation of circadian period by the prolonged presence of light. Although Drosophila melanogaster is a prominent insect model of chronobiology, there is little evidence for such continuous effects of light in the species. In this study, we demonstrate that prolonged light exposure at specific times of the day shapes the daily timing of activity in flies. We also establish that continuous UV- and blue-blocked light lengthens the circadian period of Drosophila and provide evidence that this is produced by the combined action of multiple photoreceptors which, includes the cell-autonomous photoreceptor cryptochrome. Finally, we introduce ramped light cycles as an entrainment paradigm that produces light entrainment that lacks the large light-driven startle responses typically displayed by flies and requires multiple days for entrainment to shifted cycles. These features are reminiscent of entrainment in mammalian models systems and make possible new experimental approaches to understanding the mechanisms underlying entrainment in the fly.
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Affiliation(s)
- Lakshman Abhilash
- The Advanced Science Research Center, The Graduate Center at the City University of New York, New York, NY 10031, USA
| | - Orie Thomas Shafer
- The Advanced Science Research Center, The Graduate Center at the City University of New York, New York, NY 10031, USA
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5
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Richhariya S, Shin D, Le JQ, Rosbash M. Dissecting neuron-specific functions of circadian genes using modified cell-specific CRISPR approaches. Proc Natl Acad Sci U S A 2023; 120:e2303779120. [PMID: 37428902 PMCID: PMC10629539 DOI: 10.1073/pnas.2303779120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/07/2023] [Indexed: 07/12/2023] Open
Abstract
Circadian behavioral rhythms in Drosophila melanogaster are regulated by about 75 pairs of brain neurons. They all express the core clock genes but have distinct functions and gene expression profiles. To understand the importance of these distinct molecular programs, neuron-specific gene manipulations are essential. Although RNAi based methods are standard to manipulate gene expression in a cell-specific manner, they are often ineffective, especially in assays involving smaller numbers of neurons or weaker Gal4 drivers. We and others recently exploited a neuron-specific CRISPR-based method to mutagenize genes within circadian neurons. Here, we further explore this approach to mutagenize three well-studied clock genes: the transcription factor gene vrille, the photoreceptor gene Cryptochrome (cry), and the neuropeptide gene Pdf (pigment dispersing factor). The CRISPR-based strategy not only reproduced their known phenotypes but also assigned cry function for different light-mediated phenotypes to discrete, different subsets of clock neurons. We further tested two recently published methods for temporal regulation in adult neurons, inducible Cas9 and the auxin-inducible gene expression system. The results were not identical, but both approaches successfully showed that the adult-specific knockout of the neuropeptide Pdf reproduces the canonical loss-of-function mutant phenotypes. In summary, a CRISPR-based strategy is a highly effective, reliable, and general method to temporally manipulate gene function in specific adult neurons.
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6
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Dani C, Sheeba V. Drosophila Populations Reared Under Tropical Semi-natural Conditions Evolve Season-dependent Differences in Timing of Eclosion. Front Physiol 2022; 13:954731. [PMID: 35910567 PMCID: PMC9334559 DOI: 10.3389/fphys.2022.954731] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/15/2022] [Indexed: 11/16/2022] Open
Abstract
Circadian clocks are considered an evolutionary adaptation to environmental cycles, helping organisms to adapt to daily and seasonal changes. However, most studies on the evolution of circadian rhythms have been carried out in controlled laboratory conditions; hence evolution of circadian clocks and rhythms in organisms reared under the influence of naturally varying time cues is not well understood. To address this, we reared large outbred fly populations in an outdoor enclosure on our institutional grounds in Bengaluru, southern India for about 150 generations, at the same time maintaining their ancestral control populations under standard laboratory conditions. Studying their rhythms in eclosion, a vital behavior for Drosophila, in the laboratory and semi-natural environments revealed that flies reared under semi-natural conditions differed in the timing of eclosion under semi-natural conditions in a season-dependent manner from their laboratory-reared counterparts. These differences were manifested under harsh semi-natural environments but not under mild ones or in standard laboratory conditions. Further analysis revealed that this phenotype might be responsive to seasonal changes in temperature cycles which was confirmed in the laboratory with simulated light and temperature cycles that approximated semi-natural conditions. Our results highlight key intricacies on the relative impact of intensity and timing of environmental cues for predicting the timing of Drosophila eclosion under tropical naturalistic conditions. Overall, our research uncovers previously unexplored aspects of adaptive circadian timekeeping in complex natural conditions, offering valuable insight into the evolution of clocks.
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7
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Häfker NS, Connan-McGinty S, Hobbs L, McKee D, Cohen JH, Last KS. Animal behavior is central in shaping the realized diel light niche. Commun Biol 2022; 5:562. [PMID: 35676530 PMCID: PMC9177748 DOI: 10.1038/s42003-022-03472-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractAnimal behavior in space and time is structured by the perceived day/night cycle. However, this is modified by the animals’ own movement within its habitat, creating a realized diel light niche (RDLN). To understand the RDLN, we investigated the light as experienced by zooplankton undergoing synchronized diel vertical migration (DVM) in an Arctic fjord around the spring equinox. We reveal a highly dampened light cycle with diel changes being about two orders of magnitude smaller compared to the surface or a static depth. The RDLN is further characterized by unique wavelength-specific irradiance cycles. We discuss the relevance of RDLNs for animal adaptations and interactions, as well as implications for circadian clock entrainment in the wild and laboratory.
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Kaladchibachi S, Negelspach DC, Zeitzer JM, Fernandez FX. Investigation of the aging clock's intermittent-light responses uncovers selective deficits to green millisecond flashes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 228:112389. [PMID: 35086027 DOI: 10.1016/j.jphotobiol.2022.112389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
The central pacemaker of flies, rodents, and humans generates less robust circadian output signals across normative aging. It is not well understood how changes in light sensitivity might contribute to this phenomenon. In the present study, we summarize results from an extended data series (n = 5681) showing that the locomotor activity rhythm of aged Drosophila can phase-shift normally to intermittently spaced episodes of bright polychromatic light exposure (600 lx) but that deficits emerge in response to 8, 16, and 120-millisecond flashes of narrowband blue (λm, 452 nm) and green (λm, 525 nm) LED light. For blue, phase-resetting of the activity rhythm of older flies is not as energy efficient as it is in younger flies at the fastest flash-exposures tested (8 milliseconds), suggesting there might be different floors of light duration necessary to incur photohabituation in each age group. For green, the responses of older flies are universally crippled relative to those of younger flies across the slate of protocols we tested. The difference in green flash photosensitivity is one of the most salient age-related phenotypes that has been documented in the circadian phase-shifting literature thus far. These data provide further impetus for investigations on pacemaker aging and how it might relate to changes in the circadian system's responses to particular sequences of light exposure tuned for wavelength, intensity, duration, and tempo.
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Affiliation(s)
| | | | - Jamie M Zeitzer
- Department of Psychiatry and Behavioral Sciences and Stanford Center for Sleep Sciences and Medicine, Stanford University, Stanford, CA, USA; Mental Illness Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Fabian-Xosé Fernandez
- Department of Psychology, University of Arizona, Tucson, AZ, USA; Department of Neurology, University of Arizona, Tucson, AZ, USA; BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, AZ, USA.
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9
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The Drosophila circadian phase response curve to light: Conservation across seasonally relevant photoperiods and anchorage to sunset. Physiol Behav 2021; 245:113691. [PMID: 34958825 DOI: 10.1016/j.physbeh.2021.113691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/17/2021] [Accepted: 12/23/2021] [Indexed: 12/31/2022]
Abstract
Photic history, including the relative duration of day versus night in a 24-hour cycle, is known to influence subsequent circadian responses to light in mammals. Whether such modulation is present in Drosophila is currently unknown. To date, all photic phase-response curves (PRCs) generated from Drosophila have done so with animals housed under seasonally agnostic equatorial photoperiods with alternating 12-hour segments of light and darkness. However, the genus contains thousands of species, some of which populate high and low-latitude habitats (20-50° north or south of the Equator) where seasonal variations in the light-dark schedule are pronounced. Here, we address this disconnect by constructing the first high-resolution Drosophila seasonal atlas for light-induced circadian phase-resetting. Testing the light responses of over 4,000 Drosophila at 120 timepoints across 5 seasonally-relevant rectangular photoperiods (i.e., LD 8:16, 10:14, 12:12, 14:10, and 16:8; 24 hourly intervals surveyed in each), we determined that many aspects of the fly circadian PRC waveform are conserved with increasing daylength. Surprisingly though, irrespective of LD schedule, the start of the PRCs always remained anchored to the timing of subjective sunset, creating a differential overlap of the advance zone with the morning hours after subjective sunrise that was maximized under summer photoperiods and minimized under winter photoperiods. These data suggest that there may be differences in flies versus mammals as to how the photoperiod modulates the waveform and amplitude of the circadian PRC to light. On the other hand, they support the possibility that the lights-off transition determines the phase-positioning of photic PRCs across seasons and across species. More work is necessary to test this claim and whether it might factor into the timing of seasonal light responses in humans.
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10
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Cohen JH, Last KS, Charpentier CL, Cottier F, Daase M, Hobbs L, Johnsen G, Berge J. Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biol 2021; 19:e3001413. [PMID: 34665816 PMCID: PMC8525745 DOI: 10.1371/journal.pbio.3001413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/16/2021] [Indexed: 11/18/2022] Open
Abstract
Light plays a fundamental role in the ecology of organisms in nearly all habitats on Earth and is central for processes such as vision and the entrainment of the circadian clock. The poles represent extreme light regimes with an annual light cycle including periods of Midnight Sun and Polar Night. The Arctic Ocean extends to the North Pole, and marine light extremes reach their maximum extent in this habitat. During the Polar Night, traditional definitions of day and night and seasonal photoperiod become irrelevant since there are only "twilight" periods defined by the sun's elevation below the horizon at midday; we term this "midday twilight." Here, we characterize light across a latitudinal gradient (76.5° N to 81° N) during Polar Night in January. Our light measurements demonstrate that the classical solar diel light cycle dominant at lower latitudes is modulated during Arctic Polar Night by lunar and auroral components. We therefore question whether this particular ambient light environment is relevant to behavioral and visual processes. We reveal from acoustic field observations that the zooplankton community is undergoing diel vertical migration (DVM) behavior. Furthermore, using electroretinogram (ERG) recording under constant darkness, we show that the main migratory species, Arctic krill (Thysanoessa inermis) show endogenous increases in visual sensitivity during the subjective night. This change in sensitivity is comparable to that under exogenous dim light acclimations, although differences in speed of vision suggest separate mechanisms. We conclude that the extremely weak midday twilight experienced by krill at high latitudes during the darkest parts of the year has physiological and ecological relevance.
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Affiliation(s)
- Jonathan H. Cohen
- School of Marine Science & Policy, University of Delaware, Lewes, Delaware, United States of America
- * E-mail:
| | - Kim S. Last
- Scottish Association for Marine Science, Oban, United Kingdom
| | - Corie L. Charpentier
- Department of Biology, Stetson University, DeLand, Florida, United States of America
| | - Finlo Cottier
- Scottish Association for Marine Science, Oban, United Kingdom
- UiT, The Arctic University of Norway, Faculty for Biosciences, Fisheries and Economics, Department for Arctic and Marine Biology, Tromsø, Norway
| | - Malin Daase
- UiT, The Arctic University of Norway, Faculty for Biosciences, Fisheries and Economics, Department for Arctic and Marine Biology, Tromsø, Norway
| | - Laura Hobbs
- Scottish Association for Marine Science, Oban, United Kingdom
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, United Kingdom
| | - Geir Johnsen
- University Centre in Svalbard, Longyearbyen, Norway
- Centre of Autonomous Marine Operations and Systems, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jørgen Berge
- UiT, The Arctic University of Norway, Faculty for Biosciences, Fisheries and Economics, Department for Arctic and Marine Biology, Tromsø, Norway
- University Centre in Svalbard, Longyearbyen, Norway
- Centre of Autonomous Marine Operations and Systems, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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11
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Litovchenko M, Meireles-Filho ACA, Frochaux MV, Bevers RPJ, Prunotto A, Anduaga AM, Hollis B, Gardeux V, Braman VS, Russeil JMC, Kadener S, Dal Peraro M, Deplancke B. Extensive tissue-specific expression variation and novel regulators underlying circadian behavior. SCIENCE ADVANCES 2021; 7:eabc3781. [PMID: 33514540 PMCID: PMC7846174 DOI: 10.1126/sciadv.abc3781] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 12/10/2020] [Indexed: 05/10/2023]
Abstract
Natural genetic variation affects circadian rhythms across the evolutionary tree, but the underlying molecular mechanisms are poorly understood. We investigated population-level, molecular circadian clock variation by generating >700 tissue-specific transcriptomes of Drosophila melanogaster (w1118 ) and 141 Drosophila Genetic Reference Panel (DGRP) lines. This comprehensive circadian gene expression atlas contains >1700 cycling genes including previously unknown central circadian clock components and tissue-specific regulators. Furthermore, >30% of DGRP lines exhibited aberrant circadian gene expression, revealing abundant genetic variation-mediated, intertissue circadian expression desynchrony. Genetic analysis of one line with the strongest deviating circadian expression uncovered a novel cry mutation that, as shown by protein structural modeling and brain immunohistochemistry, disrupts the light-driven flavin adenine dinucleotide cofactor photoreduction, providing in vivo support for the importance of this conserved photoentrainment mechanism. Together, our study revealed pervasive tissue-specific circadian expression variation with genetic variants acting upon tissue-specific regulatory networks to generate local gene expression oscillations.
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Affiliation(s)
- Maria Litovchenko
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Antonio C A Meireles-Filho
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Michael V Frochaux
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Roel P J Bevers
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Alessio Prunotto
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | | | - Brian Hollis
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Vincent Gardeux
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Virginie S Braman
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Julie M C Russeil
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | | | - Matteo Dal Peraro
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
| | - Bart Deplancke
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Vaud, Switzerland
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12
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Mazzotta GM, Damulewicz M, Cusumano P. Better Sleep at Night: How Light Influences Sleep in Drosophila. Front Physiol 2020; 11:997. [PMID: 33013437 PMCID: PMC7498665 DOI: 10.3389/fphys.2020.00997] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/22/2020] [Indexed: 01/25/2023] Open
Abstract
Sleep-like states have been described in Drosophila and the mechanisms and factors that generate and define sleep-wake profiles in this model organism are being thoroughly investigated. Sleep is controlled by both circadian and homeostatic mechanisms, and environmental factors such as light, temperature, and social stimuli are fundamental in shaping and confining sleep episodes into the correct time of the day. Among environmental cues, light seems to have a prominent function in modulating the timing of sleep during the 24 h and, in this review, we will discuss the role of light inputs in modulating the distribution of the fly sleep-wake cycles. This phenomenon is of growing interest in the modern society, where artificial light exposure during the night is a common trait, opening the possibility to study Drosophila as a model organism for investigating shift-work disorders.
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Affiliation(s)
| | - Milena Damulewicz
- Department of Cell Biology and Imaging, Jagiellonian University, Kraków, Poland
| | - Paola Cusumano
- Department of Biology, University of Padova, Padua, Italy
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13
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Yanagawa A, Tomaru M, Kajiwara A, Nakajima H, Quemener EDL, Steyer JP, Mitani T. Impact of 2.45 GHz Microwave Irradiation on the Fruit Fly, Drosophila melanogaster. INSECTS 2020; 11:insects11090598. [PMID: 32899629 PMCID: PMC7564283 DOI: 10.3390/insects11090598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 08/27/2020] [Accepted: 08/30/2020] [Indexed: 12/18/2022]
Abstract
Simple Summary The physiological and behavioral influences of 2.45 GHz microwaves on Drosophila melanogaster were examined. This study indicated that there was no concern regarding the thermal effects of microwave irradiation for levels of daily usage if it is traveling waves. However, it still gave non-thermal effects. We detected genotoxicity and behavioral alterations associated with travelling wave irradiation. Electron spin resonance (ESR) revealed that fruit flies possessed paramagnetic substances in the body such as Fe3+, Cu2+, Mn2+, and organic radicals, and the behavioral tests supported the microwave susceptibility of the insects. Abstract The physiological and behavioral influences of 2.45 GHz microwaves on Drosophila melanogaster were examined. Standing waves transitioned into heat energy effectively when passing through the insect body. On the contrary, travelling waves did not transit into heat energy in the insect body. This indicated that there was no concern regarding the thermal effects of microwave irradiation for levels of daily usage. However, we detected genotoxicity and behavioral alterations associated with travelling wave irradiation, which can be attributed to the non-thermal effects of the waves. Electron spin resonance (ESR) revealed that fruit flies possessed paramagnetic substances in the body such as Fe3+, Cu2+, Mn2+, and organic radicals. The temperature dependent intensities of these paramagnetic substances indicated that females possessed more of the components susceptible to electromagnetic waves than males, and the behavioral tests supported the differences between the sexes.
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Affiliation(s)
- Aya Yanagawa
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji 611-0011, Japan;
- Correspondence: (A.Y.); (E.D.-L.Q.)
| | - Masatoshi Tomaru
- Department of Drosophila Genomics and Genetic Resources, Kyoto Institute of Technology, Kyoto 616-8354, Japan;
| | - Atsushi Kajiwara
- Nara University of Education, Takabatake-cho, Nara 630-8528, Japan;
| | - Hiroki Nakajima
- Department of Molecular Chemistry, Graduate School of Kyoto Institute of Technology, Kyoto 606-8585, Japan;
| | - Elie Desmond-Le Quemener
- INRAE, Univ Montpellier, LBE, 102 avenue des Etangs, 11100 Narbonne, France;
- Correspondence: (A.Y.); (E.D.-L.Q.)
| | | | - Tomohiko Mitani
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji 611-0011, Japan;
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14
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Ogueta M, Hardie RC, Stanewsky R. Light Sampling via Throttled Visual Phototransduction Robustly Synchronizes the Drosophila Circadian Clock. Curr Biol 2020; 30:2551-2563.e3. [PMID: 32502413 DOI: 10.1016/j.cub.2020.04.067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/07/2020] [Accepted: 04/24/2020] [Indexed: 01/19/2023]
Abstract
The daily changes of light and dark exemplify a prominent cue for the synchronization of circadian clocks with the environment. The match between external and internal time is crucial for the fitness of organisms, and desynchronization has been linked to numerous physical and mental health problems. Organisms therefore developed complex and not fully understood mechanisms to synchronize their circadian clock to light. In mammals and in Drosophila, both the visual system and non-image-forming photoreceptors contribute to circadian clock resetting. In Drosophila, light-dependent degradation of the clock protein TIMELESS by the blue light photoreceptor Cryptochrome is considered the main mechanism for clock synchronization, although the visual system also contributes. To better understand the visual system contribution, we generated a genetic variant exhibiting extremely slow phototransduction kinetics, yet normal sensitivity. In this variant, the visual system is able to contribute its full share to circadian clock entrainment, both with regard to behavioral and molecular light synchronization. This function depends on an alternative phospholipase C-β enzyme, encoded by PLC21C, presumably playing a dedicated role in clock resetting. We show that this pathway requires the ubiquitin ligase CULLIN-3, possibly mediating CRY-independent degradation of TIMELESS during light:dark cycles. Our results suggest that the PLC21C-mediated contribution to circadian clock entrainment operates on a drastically slower timescale compared with fast, norpA-dependent visual phototransduction. Our findings are therefore consistent with the general idea that the visual system samples light over prolonged periods of time (h) in order to reliably synchronize their internal clocks with the external time.
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Affiliation(s)
- Maite Ogueta
- Institute of Neuro and Behavioral Biology, Westfälische Wilhelms University, 48149 Münster, Germany
| | - Roger C Hardie
- Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge CB2 3EG, UK
| | - Ralf Stanewsky
- Institute of Neuro and Behavioral Biology, Westfälische Wilhelms University, 48149 Münster, Germany.
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15
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Helfrich‐Förster C, Bertolini E, Menegazzi P. Flies as models for circadian clock adaptation to environmental challenges. Eur J Neurosci 2020; 51:166-181. [PMID: 30269385 PMCID: PMC7027873 DOI: 10.1111/ejn.14180] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 01/02/2023]
Abstract
Life on earth is assumed to have developed in tropical regions that are characterized by regular 24 hr cycles in irradiance and temperature that remain the same throughout the seasons. All organisms developed circadian clocks that predict these environmental cycles and prepare the organisms in advance for them. A central question in chronobiology is how endogenous clocks changed in order to anticipate very different cyclical environmental conditions such as extremely short and long photoperiods existing close to the poles. Flies of the family Drosophilidae can be found all over the world-from the tropics to subarctic regions-making them unprecedented models for studying the evolutionary processes that underlie the adaptation of circadian clocks to different latitudes. This review summarizes our current understanding of these processes. We discuss evolutionary changes in the clock genes and in the clock network in the brain of different Drosophilids that may have caused behavioural adaptations to high latitudes.
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Affiliation(s)
| | - Enrico Bertolini
- Neurobiology and GeneticsTheodor‐Boveri InstituteBiocentre, University of WürzburgWürzburgGermany
| | - Pamela Menegazzi
- Neurobiology and GeneticsTheodor‐Boveri InstituteBiocentre, University of WürzburgWürzburgGermany
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16
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Gamble KL, Silver R. Circadian rhythmicity and the community of clockworkers. Eur J Neurosci 2019; 51:2314-2328. [PMID: 31814204 DOI: 10.1111/ejn.14626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/17/2019] [Accepted: 11/26/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Karen L Gamble
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rae Silver
- Department of Neuroscience, Barnard College, New York, NY, USA.,Department of Psychology, Columbia University, New York, NY, USA.,Department of Pathology and Cell Biology, Columbia University Health Sciences, New York, NY, USA
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17
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Helfrich-Förster C. Light input pathways to the circadian clock of insects with an emphasis on the fruit fly Drosophila melanogaster. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 206:259-272. [PMID: 31691095 PMCID: PMC7069913 DOI: 10.1007/s00359-019-01379-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/19/2019] [Accepted: 10/26/2019] [Indexed: 12/26/2022]
Abstract
Light is the most important Zeitgeber for entraining animal activity rhythms to the 24-h day. In all animals, the eyes are the main visual organs that are not only responsible for motion and colour (image) vision, but also transfer light information to the circadian clock in the brain. The way in which light entrains the circadian clock appears, however, variable in different species. As do vertebrates, insects possess extraretinal photoreceptors in addition to their eyes (and ocelli) that are sometimes located close to (underneath) the eyes, but sometimes even in the central brain. These extraretinal photoreceptors contribute to entrainment of their circadian clocks to different degrees. The fruit fly Drosophila melanogaster is special, because it expresses the blue light-sensitive cryptochrome (CRY) directly in its circadian clock neurons, and CRY is usually regarded as the fly’s main circadian photoreceptor. Nevertheless, recent studies show that the retinal and extraretinal eyes transfer light information to almost every clock neuron and that the eyes are similarly important for entraining the fly’s activity rhythm as in other insects, or more generally spoken in other animals. Here, I compare the light input pathways between selected insect species with a focus on Drosophila’s special case.
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18
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Abstract
CRYPTOCHROMES (CRYs) are structurally related to ultraviolet (UV)/blue-sensitive DNA repair enzymes called photolyases but lack the ability to repair pyrimidine dimers generated by UV exposure. First identified in plants, CRYs have proven to be involved in light detection and various light-dependent processes in a broad range of organisms. In Drosophila, CRY's best understood role is the cell-autonomous synchronization of circadian clocks. However, CRY also contributes to the amplitude of circadian oscillations in a light-independent manner, controls arousal and UV avoidance, influences visual photoreception, and plays a key role in magnetic field detection. Here, we review our current understanding of the mechanisms underlying CRY's various circadian and noncircadian functions in fruit flies.
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Affiliation(s)
- Lauren E Foley
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Patrick Emery
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts
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19
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Kaladchibachi S, Negelspach DC, Zeitzer JM, Fernandez F. Optimization of circadian responses with shorter and shorter millisecond flashes. Biol Lett 2019; 15:20190371. [PMID: 31387472 PMCID: PMC6731482 DOI: 10.1098/rsbl.2019.0371] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022] Open
Abstract
Recent work suggests that the circadian pacemaker responds optimally to millisecond flashes of light, not continuous light exposure as has been historically believed. It is unclear whether these responses are influenced by the physical characteristics of the pulsing. In the present study, Drosophila (n = 2199) were stimulated with 8, 16 or 120 ms flashes. For each duration, the energy content of the exposure was systematically varied by changing the pulse irradiance and the number of stimuli delivered over a fixed 15 min administration window (64 protocols surveyed in all). Results showed that per microjoule invested, 8 ms flashes were more effective at resetting the circadian activity rhythm than 16- and 120 ms flashes (i.e. left shift of the dose-response curve, as well as a higher estimated maximal response). These data suggest that the circadian pacemaker's photosensitivity declines within milliseconds of light contact. Further introduction of light beyond a floor of (at least) 8 ms leads to diminishing returns on phase-shifting.
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Affiliation(s)
| | | | - Jamie M. Zeitzer
- Department of Psychiatry and Behavioral Sciences and Stanford Center for Sleep Sciences and Medicine, Stanford University, Stanford, CA, USA
- Mental Illness Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Fabian Fernandez
- Department of Psychology, University of Arizona, Tucson, AZ, USA
- Department of Neurology, University of Arizona, Tucson, AZ, USA
- BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, AZ, USA
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20
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Kurien P, Hsu PK, Leon J, Wu D, McMahon T, Shi G, Xu Y, Lipzen A, Pennacchio LA, Jones CR, Fu YH, Ptáček LJ. TIMELESS mutation alters phase responsiveness and causes advanced sleep phase. Proc Natl Acad Sci U S A 2019; 116:12045-12053. [PMID: 31138685 PMCID: PMC6575169 DOI: 10.1073/pnas.1819110116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Many components of the circadian molecular clock are conserved from flies to mammals; however, the role of mammalian Timeless remains ambiguous. Here, we report a mutation in the human TIMELESS (hTIM) gene that causes familial advanced sleep phase (FASP). Tim CRISPR mutant mice exhibit FASP with altered photic entrainment but normal circadian period. We demonstrate that the mutation prevents TIM accumulation in the nucleus and has altered affinity for CRY2, leading to destabilization of PER/CRY complex and a shortened period in nonmature mouse embryonic fibroblasts (MEFs). We conclude that TIM, when excluded from the nucleus, can destabilize the negative regulators of the circadian clock, alter light entrainment, and cause FASP.
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Affiliation(s)
- Philip Kurien
- Department of Anesthesiology, University of California, San Francisco, CA 94143
| | - Pei-Ken Hsu
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Jacy Leon
- Department of Anesthesiology, University of California, San Francisco, CA 94143
| | - David Wu
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Thomas McMahon
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Guangsen Shi
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Ying Xu
- Center for Systems Biology, Soochow University, Suzhou 215000, China
| | - Anna Lipzen
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Energy Joint Genome Institute, Walnut Creek, CA 94598
| | - Len A Pennacchio
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Energy Joint Genome Institute, Walnut Creek, CA 94598
| | | | - Ying-Hui Fu
- Department of Neurology, University of California, San Francisco, CA 94143;
- Weill Neuroscience Institute, University of California, San Francisco, CA 94143
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143
| | - Louis J Ptáček
- Department of Neurology, University of California, San Francisco, CA 94143;
- Weill Neuroscience Institute, University of California, San Francisco, CA 94143
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143
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21
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An inexpensive air stream temperature controller and its use to facilitate temperature-controlled behavior in Drosophila. Biotechniques 2019; 66:159-161. [PMID: 30869545 DOI: 10.2144/btn-2018-0152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Controlling the environment of an organism has many biologically relevant applications. Temperature-dependent inducible biological reagents have proven invaluable for elucidating signaling cascades and dissection of neural circuits. Here we develop a simple and affordable system for rapidly changing temperature in a chamber housing adult Drosophila melanogaster. Utilizing flies expressing the temperature-inducible channel dTrpA1 in dopaminergic neurons we show rapid and reproducible changes in locomotor behavior. This device should have wide application to temperature-modulated biological reagents.
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22
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A Distinct Visual Pathway Mediates High-Intensity Light Adaptation of the Circadian Clock in Drosophila. J Neurosci 2019; 39:1621-1630. [PMID: 30606757 DOI: 10.1523/jneurosci.1497-18.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 12/13/2018] [Accepted: 12/17/2018] [Indexed: 12/22/2022] Open
Abstract
To provide organisms with a fitness advantage, circadian clocks have to react appropriately to changes in their environment. High-intensity (HI) light plays an essential role in the adaptation to hot summer days, which especially endanger insects of desiccation or prey visibility. Here, we show that solely increasing light intensity leads to an increased midday siesta in Drosophila behavior. Interestingly, this change is independent of the fly's circadian photoreceptor cryptochrome and is solely caused by a small visual organ, the Hofbauer-Buchner eyelets. Using receptor knock-downs, immunostaining, and recently developed calcium tools, we show that the eyelets activate key core clock neurons, namely the s-LNvs, at HI. This activation delays the decrease of PERIOD (PER) in the middle of the day and propagates to downstream target clock neurons that prolong the siesta. We show a new pathway for integrating light-intensity information into the clock network, suggesting new network properties and surprising parallels between Drosophila and the mammalian system.SIGNIFICANCE STATEMENT The ability of animals to adapt to their ever-changing environment plays an important role in their fitness. A key player in this adaptation is the circadian clock. For animals to predict the changes of day and night, they must constantly monitor, detect and incorporate changes in the environment. The appropriate incorporation and reaction to high-intensity (HI) light is of special importance for insects because they might suffer from desiccation during hot summer days. We show here that different photoreceptors have specialized functions to integrate low-intensity, medium-intensity, or HI light into the circadian system in Drosophila These results show surprising parallels to mammalian mechanisms, which also use different photoreceptor subtypes to respond to different light intensities.
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23
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Responses to Intermittent Light Stimulation Late in the Night Phase Before Dawn. Clocks Sleep 2018; 1:26-41. [PMID: 33089153 PMCID: PMC7509681 DOI: 10.3390/clockssleep1010004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 09/26/2018] [Indexed: 12/04/2022] Open
Abstract
The circadian clock is comprised of two oscillators that independently track sunset (evening) and sunrise (morning), though little is known about how light responses differ in each. Here, we quantified the morning oscillator’s responses to 19 separate pulse trains, collecting observations from over 1300 Drosophila at ZT23. Our results show that the advances in activity onset produced by these protocols depended on the tempo of light administration even when total exposure was conserved across a 15-min window. Moreover, patterns of stimulation previously shown to optimize the evening oscillator’s delay resetting at ZT13 (an hour after dusk) were equally effective for the M oscillator at ZT23 (an hour before dawn), though the morning oscillator was by comparison more photosensitive and could benefit from a greater number of fractionation strategies that better converted light into phase-shifting drive. These data continue to build the case that the reading frames for the pacemaker’s time-of-day estimates at dusk and dawn are not uniform and suggest that the “photologic” for the evening versus morning oscillator’s resetting might be dissociable.
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24
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Somers J, Harper REF, Albert JT. How Many Clocks, How Many Times? On the Sensory Basis and Computational Challenges of Circadian Systems. Front Behav Neurosci 2018; 12:211. [PMID: 30258357 PMCID: PMC6143808 DOI: 10.3389/fnbeh.2018.00211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/21/2018] [Indexed: 11/13/2022] Open
Abstract
A vital task for every organism is not only to decide what to do but also when to do it. For this reason, "circadian clocks" have evolved in virtually all forms of life. Conceptually, circadian clocks can be divided into two functional domains; an autonomous oscillator creates a ~24 h self-sustained rhythm and sensory machinery interprets external information to alter the phase of the autonomous oscillation. It is through this simple design that variations in external stimuli (for example, daylight) can alter our sense of time. However, the clock's simplicity ends with its basic concept. In metazoan animals, multiple external and internal stimuli, from light to temperature and even metabolism have been shown to affect clock time. This raises the fundamental question of cue integration: how are the many, and potentially conflicting, sources of information combined to sense a single time of day? Moreover, individual stimuli, are often detected through various sensory pathways. Some sensory cells, such as insect chordotonal neurons, provide the clock with both temperature and mechanical information. Adding confusion to complexity, there seems to be not only one central clock in the animal's brain but numerous additional clocks in the body's periphery. It is currently not clear how (or if) these "peripheral clocks" are synchronized to their central counterparts or if both clocks "tick" independently from one another. In this review article, we would like to leave the comfort zones of conceptual simplicity and assume a more holistic perspective of circadian clock function. Focusing on recent results from Drosophila melanogaster we will discuss some of the sensory, and computational, challenges organisms face when keeping track of time.
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Affiliation(s)
- Jason Somers
- Ear Institute, University College LondonLondon, United Kingdom
- The Francis Crick InstituteLondon, United Kingdom
| | - Ross E. F. Harper
- Ear Institute, University College LondonLondon, United Kingdom
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College LondonLondon, United Kingdom
| | - Joerg T. Albert
- Ear Institute, University College LondonLondon, United Kingdom
- The Francis Crick InstituteLondon, United Kingdom
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College LondonLondon, United Kingdom
- Department of Cell and Developmental Biology, University College LondonLondon, United Kingdom
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25
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Schlichting M, Rieger D, Cusumano P, Grebler R, Costa R, Mazzotta GM, Helfrich-Förster C. Cryptochrome Interacts With Actin and Enhances Eye-Mediated Light Sensitivity of the Circadian Clock in Drosophila melanogaster. Front Mol Neurosci 2018; 11:238. [PMID: 30072870 PMCID: PMC6058042 DOI: 10.3389/fnmol.2018.00238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/19/2018] [Indexed: 11/13/2022] Open
Abstract
Cryptochromes (CRYs) are a class of flavoproteins that sense blue light. In animals, CRYs are expressed in the eyes and in the clock neurons that control sleep/wake cycles and are implied in the generation and/or entrainment of circadian rhythmicity. Moreover, CRYs are sensing magnetic fields in insects as well as in humans. Here, we show that in the fruit fly Drosophila melanogaster CRY plays a light-independent role as "assembling" protein in the rhabdomeres of the compound eyes. CRY interacts with actin and appears to increase light sensitivity of the eyes by keeping the "signalplex" of the phototransduction cascade close to the membrane. By this way, CRY also enhances light-responses of the circadian clock.
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Affiliation(s)
- Matthias Schlichting
- Neurobiology and Genetics, Biocenter, Theodor-Boveri-Institute, University of Würzburg, Würzburg, Germany
- Howard Hughes Medical Institute and National Center for Behavioral Genomics, Department of Biology, Brandeis University, Waltham, MA, United States
| | - Dirk Rieger
- Neurobiology and Genetics, Biocenter, Theodor-Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - Paola Cusumano
- Department of Biology, University of Padova, Padova, Italy
| | - Rudi Grebler
- Neurobiology and Genetics, Biocenter, Theodor-Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - Rodolfo Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Biocenter, Theodor-Boveri-Institute, University of Würzburg, Würzburg, Germany
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26
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Top D, Young MW. Coordination between Differentially Regulated Circadian Clocks Generates Rhythmic Behavior. Cold Spring Harb Perspect Biol 2018; 10:a033589. [PMID: 28893860 PMCID: PMC6028074 DOI: 10.1101/cshperspect.a033589] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Specialized groups of neurons in the brain are key mediators of circadian rhythms, receiving daily environmental cues and communicating those signals to other tissues in the organism for entrainment and to organize circadian physiology. In Drosophila, the "circadian clock" is housed in seven neuronal clusters, which are defined by their expression of the main circadian proteins, Period, Timeless, Clock, and Cycle. These clusters are distributed across the fly brain and are thereby subject to the respective environments associated with their anatomical locations. While these core components are universally expressed in all neurons of the circadian network, additional regulatory proteins that act on these components are differentially expressed, giving rise to "local clocks" within the network that nonetheless converge to regulate coherent behavioral rhythms. In this review, we describe the communication between the neurons of the circadian network and the molecular differences within neurons of this network. We focus on differences in protein-expression patterns and discuss how such variation can impart functional differences in each local clock. Finally, we summarize our current understanding of how communication within the circadian network intersects with intracellular biochemical mechanisms to ultimately specify behavioral rhythms. We propose that additional efforts are required to identify regulatory mechanisms within each neuronal cluster to understand the molecular basis of circadian behavior.
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Affiliation(s)
- Deniz Top
- Laboratory of Genetics, The Rockefeller University, New York, New York 10065
| | - Michael W Young
- Laboratory of Genetics, The Rockefeller University, New York, New York 10065
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27
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Circadian clock activity of cryptochrome relies on tryptophan-mediated photoreduction. Proc Natl Acad Sci U S A 2018; 115:3822-3827. [PMID: 29581265 DOI: 10.1073/pnas.1719376115] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cryptochromes (CRYs) entrain the circadian clocks of plants and animals to light. Irradiation of the Drosophila cryptochrome (dCRY) causes reduction of an oxidized flavin cofactor by a chain of conserved tryptophan (Trp) residues. However, it is unclear how redox chemistry within the Trp chain couples to dCRY-mediated signaling. Here, we show that substitutions of four key Trp residues to redox-active tyrosine and redox-inactive phenylalanine tune the light sensitivity of dCRY photoreduction, conformational activation, cellular stability, and targeted degradation of the clock protein timeless (TIM). An essential surface Trp gates electron flow into the flavin cofactor, but can be relocated for enhanced photoactivation. Differential effects of Trp-mediated flavin photoreduction on cellular turnover of TIM and dCRY indicate that these activities are separated in time and space. Overall, the dCRY Trp chain has evolutionary importance for light sensing, and its manipulation has implications for optogenetic applications of CRYs.
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28
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Short-term exposure to dim light at night disrupts rhythmic behaviors and causes neurodegeneration in fly models of tauopathy and Alzheimer's disease. Biochem Biophys Res Commun 2017; 495:1722-1729. [PMID: 29217196 DOI: 10.1016/j.bbrc.2017.12.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/04/2017] [Indexed: 12/14/2022]
Abstract
The accumulation and aggregation of phosphorylated tau proteins in the brain are the hallmarks for the onset of Alzheimer's disease (AD). In addition, disruptions in circadian rhythms (CRs) with altered sleep-wake cycles, dysregulation of locomotion, and increased memory defects have been reported in patients with AD. Drosophila flies that have an overexpression of human tau protein in neurons exhibit most of the symptoms of human patients with AD, including locomotion defects and neurodegeneration. Using the fly model for tauopathy/AD, we investigated the effects of an exposure to dim light at night on AD symptoms. We used a light intensity of 10 lux, which is considered the lower limit of light pollution in many countries. After the tauopathy flies were exposed to the dim light at night for 3 days, the flies showed disrupted CRs, altered sleep-wake cycles due to increased pTau proteins and neurodegeneration, in the brains of the AD flies. The results indicate that the nighttime exposure of tauopathy/AD model Drosophila flies to dim light disrupted CR and sleep-wake behavior and promoted neurodegeneration.
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29
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Kistenpfennig C, Nakayama M, Nihara R, Tomioka K, Helfrich-Förster C, Yoshii T. A Tug-of-War between Cryptochrome and the Visual System Allows the Adaptation of Evening Activity to Long Photoperiods in Drosophila melanogaster. J Biol Rhythms 2017; 33:24-34. [PMID: 29179610 DOI: 10.1177/0748730417738612] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In many animals, the circadian clock plays a role in adapting to the coming season by measuring day length. The mechanism for measuring day length and its neuronal circuits remains elusive, however. Under laboratory conditions, the fruit fly, Drosophila melanogaster, displays 2 activity peaks: one in the morning and one in the evening. These peaks appear to be regulated by 2 separate circadian oscillators (the morning and evening oscillators) that reside in different subsets of pacemaker clock neurons in the brain. The morning and evening activity peaks can flexibly change their phases to adapt to different photoperiods by tracking dawn and dusk, respectively. In this study, we found that cryptochrome (CRY) in the evening oscillators (the fifth small ventral lateral neuron [5th s-LNv] and the dorsal lateral neurons [LNds]) limits the ability of the evening peak to track dusk during long days. In contrast, light signaling from the external photoreceptors (compound eyes, ocelli, and Hofbauer-Buchner eyelets) increases the ability of the evening peak to track dusk. At the molecular level, CRY signaling dampens the amplitude of PAR-domain protein 1 (PDP1) oscillations in most clock neurons during long days, whereas signaling from the visual system increases these amplitudes. Thus, our results suggest that light inputs from the two major circadian photoreceptors, CRY and the visual system, have opposite effects on day length adaptation. Their tug-of-war appears to determine the precise phase adjustment of evening activity.
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Affiliation(s)
- Christa Kistenpfennig
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.,Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany.,2. Oxitec Ltd, 71 Innovation Drive, Milton Park, Abingdon, OX14 4RQ, UK
| | - Mayumi Nakayama
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Ruri Nihara
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Kenji Tomioka
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
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Haeme oxygenase protects against UV light DNA damages in the retina in clock-dependent manner. Sci Rep 2017; 7:5197. [PMID: 28701782 PMCID: PMC5507878 DOI: 10.1038/s41598-017-05418-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
In the present study, we showed that in the retina of Drosophila, the expression of the ho gene, encoding haeme oxygenase (HO), is regulated by light but only at the beginning of the day. This timing must be set by the circadian clock as light pulses applied at other time points during the day do not increase the ho mRNA level. Moreover, light-induced activation of HO does not depend on the canonical phototransduction pathway but instead involves cryptochrome and is enhanced by ultraviolet (UV) light. Interestingly, the level of DNA damage in the retina after UV exposure was inversely related to the circadian oscillation of the ho mRNA level during the night, being the highest when the HO level was low and reversed during the day. Accordingly, induction of HO by hemin was associated with low DNA damage, while inhibition of HO activity by SnPPIX aggravated the damage. Our data suggest that HO acts in the retina to decrease oxidative DNA damage in photoreceptors caused by UV-rich light in the morning.
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31
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Ni JD, Baik LS, Holmes TC, Montell C. A rhodopsin in the brain functions in circadian photoentrainment in Drosophila. Nature 2017; 545:340-344. [PMID: 28489826 PMCID: PMC5476302 DOI: 10.1038/nature22325] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 03/30/2017] [Indexed: 11/09/2022]
Abstract
Animals partition their daily activity rhythms through their internal circadian clocks, which are synchronized by oscillating day-night cycles of light. The fruit fly, Drosophila melanogaster, senses day/night cycles in part through rhodopsin-dependent light reception in the compound eye, and photoreceptor cells in the Hofbauer-Buchner (H-B) eyelet1. However, a more significant light entrainment pathway is mediated in central pacemaker neurons in the brain. The Drosophila circadian clock is extremely light sensitive. However, the only known light sensor in pacemaker neurons, the flavoprotein, cryptochrome (Cry)2,3, responds only to high levels of light in vitro4. These observations indicate the existence of an additional light-sensing pathway in fly pacemaker neurons5. Here, we identified an uncharacterized rhodopsin, Rh7, which functions in circadian light entrainment through circadian pacemaker neurons in the brain. The pacemaker neurons respond to violet light, which was dependent on Rh7. While loss of either cry or rh7 caused minor affects on photoentrainment, the defects in the double mutant were profound. The circadian photoresponse to constant light was impaired in the rh7 mutant, especially under dim light. The demonstration that Rh7 functions in circadian pacemaker neurons represents the first role for an opsin in the central brain.
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Affiliation(s)
- Jinfei D Ni
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106, USA.,Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Lisa S Baik
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697, USA.,Center for Circadian Biology, University of California, San Diego, La Jolla, California 92093, USA
| | - Craig Montell
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106, USA
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Arthaut LD, Jourdan N, Mteyrek A, Procopio M, El-Esawi M, d’Harlingue A, Bouchet PE, Witczak J, Ritz T, Klarsfeld A, Birman S, Usselman RJ, Hoecker U, Martino CF, Ahmad M. Blue-light induced accumulation of reactive oxygen species is a consequence of the Drosophila cryptochrome photocycle. PLoS One 2017; 12:e0171836. [PMID: 28296892 PMCID: PMC5351967 DOI: 10.1371/journal.pone.0171836] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 01/26/2017] [Indexed: 01/03/2023] Open
Abstract
Cryptochromes are evolutionarily conserved blue-light absorbing flavoproteins which participate in many important cellular processes including in entrainment of the circadian clock in plants, Drosophila and humans. Drosophila melanogaster cryptochrome (DmCry) absorbs light through a flavin (FAD) cofactor that undergoes photoreduction to the anionic radical (FAD•-) redox state both in vitro and in vivo. However, recent efforts to link this photoconversion to the initiation of a biological response have remained controversial. Here, we show by kinetic modeling of the DmCry photocycle that the fluence dependence, quantum yield, and half-life of flavin redox state interconversion are consistent with the anionic radical (FAD•-) as the signaling state in vivo. We show by fluorescence detection techniques that illumination of purified DmCry results in enzymatic conversion of molecular oxygen (O2) to reactive oxygen species (ROS). We extend these observations in living cells to demonstrate transient formation of superoxide (O2•-), and accumulation of hydrogen peroxide (H2O2) in the nucleus of insect cell cultures upon DmCry illumination. These results define the kinetic parameters of the Drosophila cryptochrome photocycle and support light-driven electron transfer to the flavin in DmCry signaling. They furthermore raise the intriguing possibility that light-dependent formation of ROS as a byproduct of the cryptochrome photocycle may contribute to its signaling role.
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Affiliation(s)
- Louis-David Arthaut
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Biomedical Engineering, Florida Institute of Technology, Melbourne, Florida, United States of America
| | | | - Ali Mteyrek
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Maria Procopio
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Physics and Astronomy, University of California, Irvine, California, United States of America
| | - Mohamed El-Esawi
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Botany Department, Faculty of Science, Tanta University, Tanta, Egypt
| | | | | | - Jacques Witczak
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
| | - Thorsten Ritz
- Department of Physics and Astronomy, University of California, Irvine, California, United States of America
| | - André Klarsfeld
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Serge Birman
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Robert J. Usselman
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Carlos F. Martino
- Department of Biomedical Engineering, Florida Institute of Technology, Melbourne, Florida, United States of America
| | - Margaret Ahmad
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Biology, Xavier University, Cincinnati, Ohio, United States of America
- * E-mail:
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33
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Cichewicz K, Garren EJ, Adiele C, Aso Y, Wang Z, Wu M, Birman S, Rubin GM, Hirsh J. A new brain dopamine-deficient Drosophila and its pharmacological and genetic rescue. GENES BRAIN AND BEHAVIOR 2016; 16:394-403. [PMID: 27762066 DOI: 10.1111/gbb.12353] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 12/12/2022]
Abstract
Dopamine (DA) is a neurotransmitter with conserved behavioral roles between invertebrate and vertebrate animals. In addition to its neural functions, in insects DA is a critical substrate for cuticle pigmentation and hardening. Drosophila tyrosine hydroxylase (DTH) is the rate limiting enzyme for DA biosynthesis. Viable brain DA-deficient flies were previously generated using tissue-selective GAL4-UAS binary expression rescue of a DTH null mutation and these flies show specific behavioral impairments. To circumvent the limitations of rescue via binary expression, here we achieve rescue utilizing genomically integrated mutant DTH. As expected, our DA-deficient flies have no detectable DTH or DA in the brain, and show reduced locomotor activity. This deficit can be rescued by l-DOPA/carbidopa feeding, similar to human Parkinson's disease treatment. Genetic rescue via GAL4/UAS-DTH was also successful, although this required the generation of a new UAS-DTH1 transgene devoid of most untranslated regions, as existing UAS-DTH transgenes express in the brain without a Gal4 driver via endogenous regulatory elements. A surprising finding of our newly constructed UAS-DTH1m is that it expresses DTH at an undetectable level when regulated by dopaminergic GAL4 drivers even when fully rescuing DA, indicating that DTH immunostaining is not necessarily a valid marker for DA expression. This finding necessitated optimizing DA immunohistochemistry, showing details of DA innervation to the mushroom body and the central complex. When DA rescue is limited to specific DA neurons, DA does not diffuse beyond the DTH-expressing terminals, such that DA signaling can be limited to very specific brain regions.
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Affiliation(s)
- K Cichewicz
- Department of Biology, University of Virginia, Charlottesville
| | - E J Garren
- Department of Biology, University of Virginia, Charlottesville
| | - C Adiele
- Department of Biology, University of Virginia, Charlottesville
| | - Y Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Z Wang
- Department of Biology, University of Virginia, Charlottesville
| | - M Wu
- Department of Biology, University of Virginia, Charlottesville
| | - S Birman
- Genes, Circuits, Rhythms and Neuropathology, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France
| | - G M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - J Hirsh
- Department of Biology, University of Virginia, Charlottesville
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34
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Eck S, Helfrich-Förster C, Rieger D. The Timed Depolarization of Morning and Evening Oscillators Phase Shifts the Circadian Clock of Drosophila. J Biol Rhythms 2016; 31:428-42. [PMID: 27269519 DOI: 10.1177/0748730416651363] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Phase response curves (PRCs) for light or temperature stimuli have been shown to be most valuable in understanding how circadian clocks are entrained to daily environmental cycles. Nowadays, PRC experiments in which clock neurons are manipulated in a temporally restricted manner by thermogenetic or optogenetic tools are also useful to comprehend clock network properties. Here, we temporally depolarized specific clock neurons of Drosophila melanogaster by activating temperature-sensitive dTrpA1 channels to unravel their role in phase shifting the flies' activity rhythm. The depolarization of all clock neurons caused a PRC resembling the flies' light PRC, with strong phase delays in the first half of the subjective night and modest phase advances in its second half. However, the activation of the flies' pigment-dispersing factor (PDF)-positive morning (M) neurons (s-LNvs) only induced phase advances, and these reached into the subjective day, where the light PRC has its dead zone. This indicates that the M neurons are very potent in accelerating the clock, which is in line with previous observations. In contrast, the evening (E) neurons together with the PDF-positive l-LNvs appear to mediate phase delays. Most interestingly, the molecular clock (Period protein cycling) of the depolarized clock neurons was shifted in parallel to the behavior, and this shift was already visible within the first cycle after the temperature pulse. We identified cAMP response element binding protein B (CREB) as a putative link between membrane depolarization and the molecular clock.
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Affiliation(s)
- Saskia Eck
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Germany
| | | | - Dirk Rieger
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Germany
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35
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van der Voet M, Harich B, Franke B, Schenck A. ADHD-associated dopamine transporter, latrophilin and neurofibromin share a dopamine-related locomotor signature in Drosophila. Mol Psychiatry 2016; 21:565-73. [PMID: 25962619 PMCID: PMC4804182 DOI: 10.1038/mp.2015.55] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 03/03/2015] [Accepted: 03/31/2015] [Indexed: 02/07/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common, highly heritable neuropsychiatric disorder with hyperactivity as one of the hallmarks. Aberrant dopamine signaling is thought to be a major theme in ADHD, but how this relates to the vast majority of ADHD candidate genes is illusive. Here we report a Drosophila dopamine-related locomotor endophenotype that is shared by pan-neuronal knockdown of orthologs of the ADHD-associated genes Dopamine transporter (DAT1) and Latrophilin (LPHN3), and of a gene causing a monogenic disorder with frequent ADHD comorbidity: Neurofibromin (NF1). The locomotor signature was not found in control models and could be ameliorated by methylphenidate, validating its relevance to symptoms of the disorder. The Drosophila ADHD endophenotype can be further exploited in high throughput to characterize the growing number of candidate genes. It represents an equally useful outcome measure for testing chemical compounds to define novel treatment options.
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Affiliation(s)
- M van der Voet
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - B Harich
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - B Franke
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
- Department of Psychiatry, Radboud university medical center, Nijmegen, The Netherlands
| | - A Schenck
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
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36
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Saint-Charles A, Michard-Vanhée C, Alejevski F, Chélot E, Boivin A, Rouyer F. Four of the six Drosophila rhodopsin-expressing photoreceptors can mediate circadian entrainment in low light. J Comp Neurol 2016; 524:2828-44. [PMID: 26972685 DOI: 10.1002/cne.23994] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/30/2022]
Abstract
Light is the major stimulus for the synchronization of circadian clocks with day-night cycles. The light-driven entrainment of the clock that controls rest-activity rhythms in Drosophila relies on different photoreceptive molecules. Cryptochrome (CRY) is expressed in most brain clock neurons, whereas six different rhodopsins (RH) are present in the light-sensing organs. The compound eye includes outer photoreceptors that express RH1 and inner photoreceptors that each express one of the four rhodopsins RH3-RH6. RH6 is also expressed in the extraretinal Hofbauer-Buchner eyelet, whereas RH2 is only found in the ocelli. In low light, the synchronization of behavioral rhythms relies on either CRY or the canonical rhodopsin phototransduction pathway, which requires the phospholipase C-β encoded by norpA (no receptor potential A). We used norpA(P24) cry(02) double mutants that are circadianly blind in low light and restored NORPA function in each of the six types of photoreceptors, defined as expressing a particular rhodopsin. We first show that the NORPA pathway is less efficient than CRY for synchronizing rest-activity rhythms with delayed light-dark cycles but is important for proper phasing, whereas the two light-sensing pathways can mediate efficient adjustments to phase advances. Four of the six rhodopsin-expressing photoreceptors can mediate circadian entrainment, and all are more efficient for advancing than for delaying the behavioral clock. In contrast, neither RH5-expressing retinal photoreceptors nor RH2-expressing ocellar photoreceptors are sufficient to mediate synchronization through the NORPA pathway. Our results thus reveal different contributions of rhodopsin-expressing photoreceptors and suggest the existence of several circuits for rhodopsin-dependent circadian entrainment. J. Comp. Neurol. 524:2828-2844, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Alexandra Saint-Charles
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Christine Michard-Vanhée
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Faredin Alejevski
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Elisabeth Chélot
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Antoine Boivin
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - François Rouyer
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
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37
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Yoshii T, Hermann-Luibl C, Helfrich-Förster C. Circadian light-input pathways in Drosophila. Commun Integr Biol 2016; 9:e1102805. [PMID: 27066180 PMCID: PMC4802797 DOI: 10.1080/19420889.2015.1102805] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 09/25/2015] [Accepted: 09/25/2015] [Indexed: 12/02/2022] Open
Abstract
Light is the most important environmental cue to entrain the circadian clock in most animals. In the fruit fly Drosophila melanogaster, the light entrainment mechanisms of the clock have been well-studied. The Drosophila brain contains approximately 150 neurons that rhythmically express circadian clock genes. These neurons are called "clock neurons" and control behavioral activity rhythms. Many clock neurons express the Cryptochrome (CRY) protein, which is sensitive to UV and blue light, and thus enables clock neurons deep in the brain to directly perceive light. In addition to the CRY protein, external photoreceptors in the Drosophila eyes play an important role in circadian light-input pathways. Recent studies have provided new insights into the mechanisms that integrate these light inputs into the circadian network of the brain. In this review, we will summarize the current knowledge on the light entrainment pathways in the Drosophila circadian clock.
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Affiliation(s)
- Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Christiane Hermann-Luibl
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
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38
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Abstract
Entrainment to environmental light/dark (LD) cycles is a central function of circadian clocks. In Drosophila, entrainment is achieved by Cryptochrome (CRY) and input from the visual system. During activation by brief light pulses, CRY triggers the degradation of TIMELESS and subsequent shift in circadian phase. This is less important for LD entrainment, leading to questions regarding light input circuits and mechanisms from the visual system. Recent studies show that different subsets of brain pacemaker clock neurons, the morning (M) and evening (E) oscillators, have distinct functions in light entrainment. However, the role of CRY in M and E oscillators for entrainment to LD cycles is unknown. Here, we address this question by selectively expressing CRY in different subsets of clock neurons in a cry-null (cry(0)) mutant background. We were able to rescue the light entrainment deficits of cry(0) mutants by expressing CRY in E oscillators but not in any other clock neurons. Par domain protein 1 molecular oscillations in the E, but not M, cells of cry(0) mutants still responded to the LD phase delay. This residual light response was stemming from the visual system because it disappeared when all external photoreceptors were ablated genetically. We concluded that the E oscillators are the targets of light input via CRY and the visual system and are required for normal light entrainment.
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Schlichting M, Grebler R, Menegazzi P, Helfrich-Förster C. Twilight Dominates Over Moonlight in Adjusting Drosophila’s Activity Pattern. J Biol Rhythms 2015; 30:117-28. [DOI: 10.1177/0748730415575245] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Light is the most important zeitgeber for the synchronization of the Drosophila melanogaster circadian clock. In nature, there is twilight, and the nights are rarely completely dark, a fact that is usually disregarded in lab experiments. Recent studies showed contrary effects of simulated twilight and moonlight on fly locomotor activity, with twilight shifting morning and evening activity into the day and moonlight shifting it into the night. A currently unanswered question is, what may happen to locomotor activity when flies are exposed to more natural conditions in which both moonlight and twilight are simulated? Our data demonstrate that flies are able to integrate twilight and moonlight. However, twilight seems to dominate over moonlight as both, morning and evening activity peaks, take place at dawn or at dusk, respectively, and not during the night. Furthermore, nocturnal activity decreases in the presence of twilight. The compound eyes are essential for this behavior, and by investigating different photoreceptor mutants, we unraveled the importance of photoreceptor cells 7 and 8 for wild-type phases of the activity peaks. To adjust nocturnal activity levels to a wild-type manner, all photoreceptor cells work together in a complex way, with rhodopsin 6 having a prominent role.
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Affiliation(s)
- Matthias Schlichting
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Rudi Grebler
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Pamela Menegazzi
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
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40
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Schlichting M, Helfrich-Förster C. Photic entrainment in Drosophila assessed by locomotor activity recordings. Methods Enzymol 2014; 552:105-23. [PMID: 25707274 DOI: 10.1016/bs.mie.2014.10.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Light is the most important Zeitgeber to entrain the circadian clock of the fruit fly Drosophila melanogaster to the 24-h cycle on earth. The fruit fly's circadian clock is very light sensitive, mainly because about half of the 150 clock neurons in the fly's brain express the blue-light photopigment, Cryptochrome, which provokes an immediate degradation of the clock protein Timeless upon activation by light. Consequently, Drosophila's molecular clock can reset very fast to measure the changes in environmental-lighting conditions. However, usually the responses of the molecular clock to light are not directly measured, but conclusions about entrainment of the circadian clock are drawn from recording the flies' locomotor activity rhythms. Here, we review how the flies' locomotor activity can be recorded under different light regimes and how entrainment can be analyzed and properly judged. We also summarize the influence of different recording and lighting methods on the flies' activity pattern, highlight their advantages and disadvantages, and stress general pitfalls.
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Affiliation(s)
- Matthias Schlichting
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany.
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41
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Lee E, Jeong EH, Jeong HJ, Yildirim E, Vanselow JT, Ng F, Liu Y, Mahesh G, Kramer A, Hardin PE, Edery I, Kim EY. Phosphorylation of a central clock transcription factor is required for thermal but not photic entrainment. PLoS Genet 2014; 10:e1004545. [PMID: 25121504 PMCID: PMC4133166 DOI: 10.1371/journal.pgen.1004545] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/17/2014] [Indexed: 01/04/2023] Open
Abstract
Transcriptional/translational feedback loops drive daily cycles of expression in clock genes and clock-controlled genes, which ultimately underlie many of the overt circadian rhythms manifested by organisms. Moreover, phosphorylation of clock proteins plays crucial roles in the temporal regulation of clock protein activity, stability and subcellular localization. dCLOCK (dCLK), the master transcription factor driving cyclical gene expression and the rate-limiting component in the Drosophila circadian clock, undergoes daily changes in phosphorylation. However, the physiological role of dCLK phosphorylation is not clear. Using a Drosophila tissue culture system, we identified multiple phosphorylation sites on dCLK. Expression of a mutated version of dCLK where all the mapped phospho-sites were switched to alanine (dCLK-15A) rescues the arrythmicity of Clkout flies, yet with an approximately 1.5 hr shorter period. The dCLK-15A protein attains substantially higher levels in flies compared to the control situation, and also appears to have enhanced transcriptional activity, consistent with the observed higher peak values and amplitudes in the mRNA rhythms of several core clock genes. Surprisingly, the clock-controlled daily activity rhythm in dCLK-15A expressing flies does not synchronize properly to daily temperature cycles, although there is no defect in aligning to light/dark cycles. Our findings suggest a novel role for clock protein phosphorylation in governing the relative strengths of entraining modalities by adjusting the dynamics of circadian gene expression. Circadian clocks are synchronized to local time by daily cycles in light-dark and temperature. Although light is generally thought to be the most dominant entraining cue in nature, daily cycles in temperature are sufficient to synchronize clocks in a large range of organisms. In Drosophila, dCLOCK is a master circadian transcription factor that drives cyclical gene expression and is likely the rate-limiting component in the transcriptional/translational feedback loops that underlie the timekeeping mechanism. dCLOCK undergoes temporal changes in phosphorylation throughout a day, which is also observed for mammalian CLOCK. However, the role of CLOCK phosphorylation at the organismal level is still unclear. Using mass-spectrometry, we identified more than a dozen phosphorylation sites on dCLOCK. Blocking global phosphorylation of dCLOCK by mutating phospho-acceptor sites to alanine increases its abundance and transcriptional activity, leading to higher peak values and amplitudes in the mRNA rhythms of core clock genes, which likely explains the accelerated clock speed. Surprisingly, the clock-controlled daily activity rhythm fails to maintain synchrony with daily temperature cycles, although there is no observable defect in aligning to light/dark cycles. Our findings suggest a novel role for clock protein phosphorylation in governing the effective strengths of entraining modalities by adjusting clock amplitude.
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Affiliation(s)
- Euna Lee
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
- Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
| | - Eun Hee Jeong
- Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
| | - Hyun-Jeong Jeong
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
| | - Evrim Yildirim
- Department of Molecular Biology and Biochemistry, Rutgers University, Center for Advanced Biotechnology and Medicine, Piscataway, New Jersey, United States of America
| | - Jens T. Vanselow
- Laboratory of Chronobiology, Charité–Universitätsmedizin, Berlin, Germany
| | - Fanny Ng
- Texas A&M University Department of Biology and Center for Biological Clocks Research, College Station, Texas, United States of America
| | - Yixiao Liu
- Texas A&M University Department of Biology and Center for Biological Clocks Research, College Station, Texas, United States of America
| | - Guruswamy Mahesh
- Texas A&M University Department of Biology and Center for Biological Clocks Research, College Station, Texas, United States of America
| | - Achim Kramer
- Laboratory of Chronobiology, Charité–Universitätsmedizin, Berlin, Germany
| | - Paul E. Hardin
- Texas A&M University Department of Biology and Center for Biological Clocks Research, College Station, Texas, United States of America
| | - Isaac Edery
- Department of Molecular Biology and Biochemistry, Rutgers University, Center for Advanced Biotechnology and Medicine, Piscataway, New Jersey, United States of America
- * E-mail: (IE); (EYK)
| | - Eun Young Kim
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
- Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, Republic of Korea
- * E-mail: (IE); (EYK)
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Oliveri P, Fortunato AE, Petrone L, Ishikawa-Fujiwara T, Kobayashi Y, Todo T, Antonova O, Arboleda E, Zantke J, Tessmar-Raible K, Falciatore A. The Cryptochrome/Photolyase Family in aquatic organisms. Mar Genomics 2014; 14:23-37. [DOI: 10.1016/j.margen.2014.02.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 01/12/2023]
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Tataroglu O, Emery P. Studying circadian rhythms in Drosophila melanogaster. Methods 2014; 68:140-50. [PMID: 24412370 DOI: 10.1016/j.ymeth.2014.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 01/02/2014] [Indexed: 11/25/2022] Open
Abstract
Circadian rhythms have a profound influence on most bodily functions: from metabolism to complex behaviors. They ensure that all these biological processes are optimized with the time-of-day. They are generated by endogenous molecular oscillators that have a period that closely, but not exactly, matches day length. These molecular clocks are synchronized by environmental cycles such as light intensity and temperature. Drosophila melanogaster has been a model organism of choice to understand genetically, molecularly and at the level of neural circuits how circadian rhythms are generated, how they are synchronized by environmental cues, and how they drive behavioral cycles such as locomotor rhythms. This review will cover a wide range of techniques that have been instrumental to our understanding of Drosophila circadian rhythms, and that are essential for current and future research.
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Affiliation(s)
- Ozgur Tataroglu
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, United States
| | - Patrick Emery
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, United States.
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Varma V, Mukherjee N, Kannan NN, Sharma VK. Strong (type 0) phase resetting of activity-rest rhythm in fruit flies, Drosophila melanogaster, at low temperature. J Biol Rhythms 2013; 28:380-9. [PMID: 24336416 DOI: 10.1177/0748730413508922] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Amplitude modulation in limit cycle models of circadian clocks has been previously formulated to explain the phenomenon of temperature compensation. These models propose that invariance of clock period (τ) with changing temperature is a result of the system traversing small or large limit cycles such that despite a decrease or an increase in the linear velocity of the clock owing to slowing down or speeding up of the underlying biochemical reactions, respectively, the angular velocity and, thus, the clock period remain constant. In addition, these models predict that phase resetting behavior of circadian clocks described by limit cycles of different amplitudes at low or high temperatures will be drastically different. More specifically, this class of models predicts that at low temperatures, circadian clocks will respond to perturbations by eliciting larger phase shifts by virtue of their smaller amplitude and vice versa. Here, we present the results of our tests of this prediction: We examined the nature of photic phase response curves (PRCs) and phase transition curves (PTCs) for the circadian clocks of 4 wild-type fruit fly Drosophila melanogaster populations at 3 different ambient temperatures (18, 25, and 29 °C). Interestingly, we observed that at the low temperature of 18 °C, fly clocks respond to light perturbations more strongly, eliciting strong (type 0) PRCs and PTCs, while at moderate (25 °C) and high (29 °C) temperatures the same stimuli evoke weak (type 1) responses. This pattern of strong and weak phase resetting at low and high temperatures, respectively, renders support for the limit cycle amplitude modulation model for temperature compensation of circadian clocks.
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Affiliation(s)
- Vishwanath Varma
- Chronobiology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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