start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230523 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A four-oscillator model of seasonally adapted morning and evening activities in Drosophila melanogaster en-subtitle= kn-subtitle= en-abstract= kn-abstract=The fruit fly Drosophila melanogaster exhibits two activity peaks, one in the morning and another in the evening. Because the two peaks change phase depending on the photoperiod they are exposed to, they are convenient for studying responses of the circadian clock to seasonal changes. To explain the phase determination of the two peaks, Drosophila researchers have employed the two-oscillator model, in which two oscillators control the two peaks. The two oscillators reside in different subsets of neurons in the brain, which express clock genes, the so-called clock neurons. However, the mechanism underlying the activity of the two peaks is complex and requires a new model for mechanistic exploration. Here, we hypothesize a four-oscillator model that controls the bimodal rhythms. The four oscillators that reside in different clock neurons regulate activity in the morning and evening and sleep during the midday and at night. In this way, bimodal rhythms are formed by interactions among the four oscillators (two activity and two sleep oscillators), which may judiciously explain the flexible waveform of activity rhythms under different photoperiod conditions. Although still hypothetical, this model would provide a new perspective on the seasonal adaptation of the two activity peaks. en-copyright= kn-copyright= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SaitoAika en-aut-sei=Saito en-aut-mei=Aika kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YokosakoTatsuya en-aut-sei=Yokosako en-aut-mei=Tatsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Drosophila kn-keyword=Drosophila en-keyword=Seasonal adaptation kn-keyword=Seasonal adaptation en-keyword=Photoperiod kn-keyword=Photoperiod en-keyword=Oscillator kn-keyword=Oscillator en-keyword=Activity rhythm kn-keyword=Activity rhythm END start-ver=1.4 cd-journal=joma no-vol=40 cd-vols= no-issue=3 article-no= start-page=284 end-page=299 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=2023214 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Pigment-dispersing factor and CCHamide1 in the Drosophila circadian clock network en-subtitle= kn-subtitle= en-abstract= kn-abstract=Animals possess a circadian central clock in the brain, where circadian behavioural rhythms are generated. In the fruit fly (Drosophila melanogaster), the central clock comprises a network of approximately 150 clock neurons, which is important for the maintenance of a coherent and robust rhythm. Several neuropeptides involved in the network have been identified, including Pigment-dispersing factor (PDF) and CCHamide1 (CCHa1) neuropeptides. PDF signals bidirectionally to CCHa1-positive clock neurons; thus, the clock neuron groups expressing PDF and CCHa1 interact reciprocally. However, the role of these interactions in molecular and behavioural rhythms remains elusive. In this study, we generated Pdf (01) and CCHa1(SK8) double mutants and examined their locomotor activity-related rhythms. The single mutants of Pdf (01) or CCHa1(SK8) displayed free-running rhythms under constant dark conditions, whereas approximately 98% of the double mutants were arrhythmic. In light-dark conditions, the evening activity of the double mutants was phase-advanced compared with that of the single mutants. In contrast, both the single and double mutants had diminished morning activity. These results suggest that the effects of the double mutation varied in behavioural parameters. The double and triple mutants of per (01), Pdf (01), and CCHa1(SK8) further revealed that PDF signalling plays a role in the suppression of activity during the daytime under a clock-less background. Our results provide insights into the interactions between PDF and CCHa1 signalling and their roles in activity rhythms. en-copyright= kn-copyright= en-aut-name=KuwanoRiko en-aut-sei=Kuwano en-aut-mei=Riko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KatsuraMaki en-aut-sei=Katsura en-aut-mei=Maki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=IwataMai en-aut-sei=Iwata en-aut-mei=Mai kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YokosakoTatsuya en-aut-sei=Yokosako en-aut-mei=Tatsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Neuropeptide kn-keyword=Neuropeptide en-keyword=neural network kn-keyword=neural network en-keyword=clock protein kn-keyword=clock protein en-keyword=activity rhythm kn-keyword=activity rhythm en-keyword=masking effect kn-keyword=masking effect END start-ver=1.4 cd-journal=joma no-vol=128 cd-vols= no-issue= article-no= start-page=453 end-page=460 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220329 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Artificial selections for death-feigning behavior in beetles show correlated responses in amplitude of circadian rhythms, but the period of the rhythm does not en-subtitle= kn-subtitle= en-abstract= kn-abstract=One of the most important survival strategies of organisms is to avoid predators. Studying one of such strategies, namely, death-feigning behavior, has recently become more common. The success or failure of this antipredator strategy will be affected by the circadian rhythms of both prey and predator because death feigning sometimes has a diurnal rhythm. However, few studies have analyzed the effects of differences in circadian rhythms on predator-avoidance behavior at the genetic level. Recently, the relationship between genes relating to circadian rhythm and death-feigning behavior, an antipredator behavior, has been established at the molecular level. Therefore, in this study, we compared three circadian rhythm-related traits, the free-running period of rhythms, amplitude of circadian rhythms, and total activity of strains of three Tribolium species that were artificially selected for the death-feigning duration: short (S-strains) and long (L-strains) durations. As a result, the amplitude of circadian rhythms and total activity were significantly different between S- and L-strains, but there was no difference in the free-running periods of the rhythm between the strains in T. castaneum, T. confusum, and T. freemani. Although the relationship between death-feigning behavior and activity has been reported for all three species, a genetic relationship between the duration of death feigning and the amplitude of circadian rhythms has been newly found in the present study. It is important to investigate the relationship between antipredator strategies and circadian rhythms at the molecular level in the future. en-copyright= kn-copyright= en-aut-name=MiyatakeTakahisa en-aut-sei=Miyatake en-aut-mei=Takahisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=S. AbeMasato en-aut-sei=S. Abe en-aut-mei=Masato kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MatsumuraKentarou en-aut-sei=Matsumura en-aut-mei=Kentarou kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=2 en-affil=Center for Advanced Intelligence Project, RIKEN kn-affil= affil-num=3 en-affil=Laboratory of entomology, Faculty of Agriculture kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=biological clock kn-keyword=biological clock en-keyword=coleoptera kn-keyword=coleoptera en-keyword=death feigning kn-keyword=death feigning en-keyword=thanatosis kn-keyword=thanatosis en-keyword=tonic immobility kn-keyword=tonic immobility END start-ver=1.4 cd-journal=joma no-vol=16 cd-vols= no-issue=1 article-no= start-page=e0245115 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210114 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Amplitude of circadian rhythms becomes weaken in the north, but there is no cline in the period of rhythm in a beetle en-subtitle= kn-subtitle= en-abstract= kn-abstract=Many species show rhythmicity in activity, from the timing of flowering in plants to that of foraging behavior in animals. The free-running periods and amplitude (sometimes called strength or power) of circadian rhythms are often used as indicators of biological clocks. Many reports have shown that these traits are highly geographically variable, and interestingly, they often show latitudinal or longitudinal clines. In many cases, the higher the latitude is, the longer the free-running circadian period (i.e., period of rhythm) in insects and plants. However, reports of positive correlations between latitude or longitude and circadian rhythm traits, including free-running periods, the power of the rhythm and locomotor activity, are limited to certain taxonomic groups. Therefore, we collected a cosmopolitan stored-product pest species, the red flour beetle Tribolium castaneum, in various parts of Japan and examined its rhythm traits, including the power and period of the rhythm, which were calculated from locomotor activity. The analysis revealed that the power was significantly lower for beetles collected in northern areas than southern areas in Japan. However, it is worth noting that the period of circadian rhythm did not show any clines; specifically, it did not vary among the sampling sites, despite the very large sample size (n = 1585). We discuss why these cline trends were observed in T. castaneum. en-copyright= kn-copyright= en-aut-name=AbeMasato S. en-aut-sei=Abe en-aut-mei=Masato S. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsumuraKentarou en-aut-sei=Matsumura en-aut-mei=Kentarou kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MiyatakeTakahisa en-aut-sei=Miyatake en-aut-mei=Takahisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Center for Advanced Intelligence Project, RIKEN kn-affil= affil-num=2 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=3 en-affil= Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=130 cd-vols= no-issue=1 article-no= start-page=34 end-page=40 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200507 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Genetic variation and phenotypic plasticity in circadian rhythms in an armed beetle, Gnatocerus cornutus (Tenebrionidae) en-subtitle= kn-subtitle= en-abstract= kn-abstract=Circadian rhythms, their free-running periods and the power of the rhythms are often used as indicators of biological clocks, and there is evidence that the free-running periods of circadian rhythms are not affected by environmental factors, such as temperature. However, there are few studies of environmental effects on the power of the rhythms, and it is not clear whether temperature compensation is universal. Additionally, genetic variation and phenotypic plasticity in biological clocks are important for understanding the evolution of biological rhythms, but genetic and plastic effects are rarely investigated. Here, we used 18 isofemale lines (genotypes) of Gnatocerus cornutus to assess rhythms of locomotor activity, while also testing for temperature effects. We found that total activity and the power of the circadian rhythm were affected by interactions between sex and genotype or between sex, genotype and temperature. The males tended to be more active and showed greater increases in activity, but this effect varied across both genotypes and temperatures. The period of activity varied only by genotype and was thus independent of temperature. The complicated genotype?sex?environment interactions we recorded stress the importance of investigating circadian activity in more integrated ways. en-copyright= kn-copyright= en-aut-name=MatsumuraKentarou en-aut-sei=Matsumura en-aut-mei=Kentarou kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AbeMasato S en-aut-sei=Abe en-aut-mei=Masato S kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SharmaManmohan D en-aut-sei=Sharma en-aut-mei=Manmohan D kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HoskenDavid J en-aut-sei=Hosken en-aut-mei=David J kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MiyatakeTakahisa en-aut-sei=Miyatake en-aut-mei=Takahisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=2 en-affil=Center for Advanced Intelligence Project, RIKEN kn-affil= affil-num=3 en-affil=Centre for Ecology and Conservation, School of Biosciences, University of Exeter kn-affil= affil-num=4 en-affil=Centre for Ecology and Conservation, School of Biosciences, University of Exeter kn-affil= affil-num=5 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=6 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= en-keyword=circadian rhythm kn-keyword=circadian rhythm en-keyword=Gnatocerus cornutus kn-keyword=Gnatocerus cornutus en-keyword=isofemale line kn-keyword=isofemale line en-keyword=power of circadian rhythm kn-keyword=power of circadian rhythm END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20191219 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A Catalog of GAL4 Drivers for Labeling and Manipulating Circadian Clock Neurons in Drosophila melanogaster en-subtitle= kn-subtitle= en-abstract= kn-abstract= Daily rhythms of physiology, metabolism, and behavior are orchestrated by a central circadian clock. In mice, this clock is coordinated by the suprachiasmatic nucleus, which consists of 20,000 neurons, making it challenging to characterize individual neurons. In Drosophila, the clock is controlled by only 150 clock neurons that distribute across the fly's brain. Here, we describe a comprehensive set of genetic drivers to facilitate individual characterization of Drosophila clock neurons. We screened GAL4 lines that were obtained from Drosophila stock centers and identified 63 lines that exhibit expression in subsets of central clock neurons. Furthermore, we generated split-GAL4 lines that exhibit specific expression in subsets of clock neurons such as the 2 DN2 neurons and the 6 LPN neurons. Together with existing driver lines, these newly identified ones are versatile tools that will facilitate a better understanding of the Drosophila central circadian clock. en-copyright= kn-copyright= en-aut-name=SekiguchiManabu en-aut-sei=Sekiguchi en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=InoueKotaro en-aut-sei=Inoue en-aut-mei=Kotaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YangTian en-aut-sei=Yang en-aut-mei=Tian kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=LuoDong-Gen en-aut-sei=Luo en-aut-mei=Dong-Gen kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Matching Program Course, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Drosophila kn-keyword=Drosophila en-keyword=clock neuron kn-keyword=clock neuron en-keyword=split-GAL4 kn-keyword=split-GAL4 END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=15 article-no= start-page=6131 end-page=6141 dt-received= dt-revised= dt-accepted= dt-pub-year=2015 dt-pub=20150415 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Cryptochrome-dependent and -independent circadian entrainment circuits in Drosophila. en-subtitle= kn-subtitle= en-abstract= kn-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 (cry0) mutant background. We were able to rescue the light entrainment deficits of cry0 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 cry0 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. en-copyright= kn-copyright= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=Hermann-LuiblChristiane en-aut-sei=Hermann-Luibl en-aut-mei=Christiane kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KistenpfennigChrista en-aut-sei=Kistenpfennig en-aut-mei=Christa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SchmidBenjamin en-aut-sei=Schmid en-aut-mei=Benjamin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TomiokaKenji en-aut-sei=Tomioka en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=Helfrich-F?rsterCharlotte en-aut-sei=Helfrich-F?rster en-aut-mei=Charlotte kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Graduate School of Natural Science and Technology, Okayama University affil-num=2 en-affil= kn-affil=Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of W?rzburg affil-num=3 en-affil= kn-affil=Graduate School of Natural Science and Technology, Okayama University affil-num=4 en-affil= kn-affil=Max Planck Institute of Molecular Cell Biology and Genetics affil-num=5 en-affil= kn-affil=Graduate School of Natural Science and Technology, Okayama University affil-num=6 en-affil= kn-affil=2Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of W?rzburg en-keyword=circadian clock kn-keyword=circadian clock en-keyword=clock neurons kn-keyword=clock neurons en-keyword=Cryptochrome kn-keyword=Cryptochrome en-keyword=Drosophila melanogaster kn-keyword=Drosophila melanogaster en-keyword=light entrainment kn-keyword=light entrainment END start-ver=1.4 cd-journal=joma no-vol=12 cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2015 dt-pub=201506 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Molecular features of the circadian clock system in fruit flies en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name=gu kn-aut-sei=g kn-aut-mei=u aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=Laboratory of Chronobiology, Graduate School of Natural Science and Technology, Okayama University END