start-ver=1.4 cd-journal=joma no-vol=11 cd-vols= no-issue=1 article-no= start-page=2 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250128 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effect of temperature cycles on the sleep-like state in Hydra vulgaris en-subtitle= kn-subtitle= en-abstract= kn-abstract=Background Sleep is a conserved physiological phenomenon across species. It is mainly controlled by two processes: a circadian clock that regulates the timing of sleep and a homeostat that regulates the sleep drive. Even cnidarians, such as Hydra and jellyfish, which lack a brain, display sleep-like states. However, the manner in which environmental cues affect sleep-like states in these organisms remains unknown. In the present study, we investigated the effects of light and temperature cycles on the sleep-like state in Hydra vulgaris.
Results Our findings indicate that Hydra responds to temperature cycles with a difference of up to 5 C, resulting in decreased sleep duration under light conditions and increased sleep duration in dark conditions. Furthermore, our results reveal that Hydra prioritizes temperature changes over light as an environmental cue. Additionally, our body resection experiments show tissue-specific responsiveness in the generation ofthe sleep-like state under different environmental cues. Specifically, the upper body can generate the sleep-like state in response to a single environmental cue. In contrast, the lower body did not respond to 12-h light?dark cycles at a constant temperature.
Conclusions These findings indicate that both light and temperature influence the regulation of the sleep-like state in Hydra. Moreover, these observations highlight the existence of distinct regulatory mechanisms that govern patterns of the sleep-like state in brainless organisms, suggesting the potential involvement of specific regions for responsiveness of environmental cues for regulation of the sleep-like state. en-copyright= kn-copyright= en-aut-name=SatoAya en-aut-sei=Sato en-aut-mei=Aya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SekiguchiManabu en-aut-sei=Sekiguchi en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakadaKoga en-aut-sei=Nakada en-aut-mei=Koga 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= en-aut-name=ItohTaichi Q. en-aut-sei=Itoh en-aut-mei=Taichi Q. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Faculty of Arts and Science, Kyushu 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 Systems Life Sciences, Kyushu University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Faculty of Arts and Science, Kyushu University kn-affil= en-keyword=Hydra kn-keyword=Hydra en-keyword=Sleep kn-keyword=Sleep en-keyword=Temperature kn-keyword=Temperature en-keyword=Environmental cues kn-keyword=Environmental cues END start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue=1 article-no= start-page=10819 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20241230 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A high-protein diet-responsive gut hormone regulates behavioral and metabolic optimization in Drosophila melanogaster en-subtitle= kn-subtitle= en-abstract= kn-abstract=Protein is essential for all living organisms; however, excessive protein intake can have adverse effects, such as hyperammonemia. Although mechanisms responding to protein deficiency are well-studied, there is a significant gap in our understanding of how organisms adaptively suppress excessive protein intake. In the present study, utilizing the fruit fly, Drosophila melanogaster, we discover that the peptide hormone CCHamide1 (CCHa1), secreted by enteroendocrine cells in response to a high-protein diet (HPD), is vital for suppressing overconsumption of protein. Gut-derived CCHa1 is received by a small subset of enteric neurons that produce short neuropeptide F, thereby modulating protein-specific satiety. Importantly, impairment of the CCHa1-mediated gut-enteric neuronal axis results in ammonia accumulation and a shortened lifespan under HPD conditions. Collectively, our findings unravel the crosstalk of gut hormone and neuronal pathways that orchestrate physiological responses to prevent and adapt to dietary protein overload. en-copyright= kn-copyright= en-aut-name=YoshinariYuto en-aut-sei=Yoshinari en-aut-mei=Yuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishimuraTakashi en-aut-sei=Nishimura en-aut-mei=Takashi 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=KondoShu en-aut-sei=Kondo en-aut-mei=Shu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TanimotoHiromu en-aut-sei=Tanimoto en-aut-mei=Hiromu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KobayashiTomoe en-aut-sei=Kobayashi en-aut-mei=Tomoe kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=MatsuyamaMakoto en-aut-sei=Matsuyama en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NiwaRyusuke en-aut-sei=Niwa en-aut-mei=Ryusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University kn-affil= affil-num=2 en-affil=Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University kn-affil= affil-num=3 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science kn-affil= affil-num=5 en-affil=Graduate School of Life Sciences, Tohoku University kn-affil= affil-num=6 en-affil=Division of Molecular Genetics, Shigei Medical Research Institute kn-affil= affil-num=7 en-affil=Division of Molecular Genetics, Shigei Medical Research Institute kn-affil= affil-num=8 en-affil=Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba kn-affil= 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=2025 dt-pub=20250710 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Neurotransmitter and Receptor Mapping in Drosophila Circadian Clock Neurons via T2A-GAL4 Screening en-subtitle= kn-subtitle= en-abstract= kn-abstract=The circadian neuronal network in the brain comprises central pacemaker neurons and associated input and output pathways. These components work together to generate coherent rhythmicity, synchronize with environmental time cues, and convey circadian information to downstream neurons that regulate behaviors such as the sleep/wake cycle. To mediate these functions, neurotransmitters and neuromodulators play essential roles in transmitting and modulating signals between neurons. In Drosophila melanogaster, approximately 240 brain neurons function as clock neurons. Previous studies have identified several neurotransmitters and neuromodulators, including the Pigment-dispersing factor (PDF) neuropeptide, along with their corresponding receptors in clock neurons. However, our understanding of the neurotransmitters and receptors involved in the circadian system remains incomplete. In this study, we conducted a T2A-GAL4-based screening for neurotransmitter and receptor genes expressed in clock neurons. We identified 2 neurotransmitter-related genes and 22 receptor genes. Notably, while previous studies had reported the expression of 6 neuropeptide receptor genes in large ventrolateral neurons (l-LNv), we also found that 14 receptor genes?including those for dopamine, serotonin, and -aminobutyric acid?are expressed in l-LNv neurons. These findings suggest that l-LNv neurons serve as key integrative hubs within the circadian network, receiving diverse external signals. en-copyright= kn-copyright= en-aut-name=FukudaAyumi en-aut-sei=Fukuda en-aut-mei=Ayumi 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=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi 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 Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= en-keyword=clock neurons kn-keyword=clock neurons en-keyword=neurotransmitter kn-keyword=neurotransmitter en-keyword=T2A-GAL4 kn-keyword=T2A-GAL4 en-keyword=immunostaining kn-keyword=immunostaining en-keyword=Drosophila kn-keyword=Drosophila END start-ver=1.4 cd-journal=joma no-vol=166 cd-vols= no-issue=8 article-no= start-page=bqaf102 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250605 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Neuromedin U Deficiency Disrupts Daily Testosterone Fluctuation and Reduces Wheel-running Activity in Rats en-subtitle= kn-subtitle= en-abstract= kn-abstract=The objective of this study was to elucidate the role of endogenous Neuromedin U (NMU) in rats by performing NMU knockout (KO). Male, but not female NMU KO rats exhibited decreased wheel-running activity vs wildtype (WT), although overall home cage activity was not affected. Plasma testosterone in WT rats varied significantly over the course of a day, with a peak at ZT1 and a nadir at ZT18, whereas in NMU KO rats testosterone remained stable throughout the day. Chronic administration of testosterone restored wheel-running activity in NMU KO rats to the same level as in WT rats, suggesting that the decrease in wheel-running activity in NMU KO rats is due to the disruption of the diurnal change of testosterone. Accordingly, expression of the luteinizing hormone beta subunit (Lhb) mRNA in the pars distalis of anterior pituitary was significantly lower in NMU KO rats; immunostaining revealed that the size of luteinizing hormone (LH)?expressing cells was also relatively small in those animals. In the brain of male WT rats, Nmu was highly expressed in the pars tuberalis, and the NMU receptor Nmur2 was highly expressed in the ependymal cell layer of the third ventricle. This study reveals a novel function of NMU and indicates that endogenous NMU in rats plays a role in the regulation of motivated activity via regulation of testosterone. en-copyright= kn-copyright= en-aut-name=OtsukaMai en-aut-sei=Otsuka en-aut-mei=Mai kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakeuchiYu en-aut-sei=Takeuchi en-aut-mei=Yu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MoriyamaMaho en-aut-sei=Moriyama en-aut-mei=Maho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=EgoshiSakura en-aut-sei=Egoshi en-aut-mei=Sakura kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=GotoYuki en-aut-sei=Goto en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=GuTingting en-aut-sei=Gu en-aut-mei=Tingting kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KimuraAtsushi P en-aut-sei=Kimura en-aut-mei=Atsushi P kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=HaraguchiShogo en-aut-sei=Haraguchi en-aut-mei=Shogo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 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=9 ORCID= en-aut-name=TakeuchiSakae en-aut-sei=Takeuchi en-aut-mei=Sakae kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=MatsuyamaMakoto en-aut-sei=Matsuyama en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=BentleyGeorge E en-aut-sei=Bentley en-aut-mei=George E kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=AizawaSayaka en-aut-sei=Aizawa en-aut-mei=Sayaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 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=Department of Biology, Faculty of Science, Okayama University 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, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=7 en-affil=Department of Biological Sciences, Faculty of Science, Hokkaido University kn-affil= affil-num=8 en-affil=Department of Biochemistry, Showa University School of Medicine kn-affil= affil-num=9 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=10 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=11 en-affil=Division of Molecular Genetics, Shigei Medical Research Institute kn-affil= affil-num=12 en-affil=Department of Integrative Biology and Helen Wills Neuroscience Institute, University of California at Berkeley kn-affil= affil-num=13 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Neuromedin U kn-keyword=Neuromedin U en-keyword=rat kn-keyword=rat en-keyword=motivation kn-keyword=motivation en-keyword=activity kn-keyword=activity en-keyword=testosterone kn-keyword=testosterone en-keyword=wheel-running kn-keyword=wheel-running END start-ver=1.4 cd-journal=joma no-vol=39 cd-vols= no-issue=5 article-no= start-page=463 end-page=483 dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240731 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A Detailed Re-Examination of the Period Gene Rescue Experiments Shows That Four to Six Cryptochrome-Positive Posterior Dorsal Clock Neurons (DN1p) of Drosophila melanogaster Can Control Morning and Evening Activity en-subtitle= kn-subtitle= en-abstract= kn-abstract=Animal circadian clocks play a crucial role in regulating behavioral adaptations to daily environmental changes. The fruit fly Drosophila melanogaster exhibits 2 prominent peaks of activity in the morning and evening, known as morning (M) and evening (E) peaks. These peaks are controlled by 2 distinct circadian oscillators located in separate groups of clock neurons in the brain. To investigate the clock neurons responsible for the M and E peaks, a cell-specific gene expression system, the GAL4-UAS system, has been commonly employed. In this study, we re-examined the two-oscillator model for the M and E peaks of Drosophila by utilizing more than 50 Gal4 lines in conjunction with the UAS-period16 line, which enables the restoration of the clock function in specific cells in the period (per) null mutant background. Previous studies have indicated that the group of small ventrolateral neurons (s-LNv) is responsible for controlling the M peak, while the other group, consisting of the 5th ventrolateral neuron (5th LNv) and the three cryptochrome (CRY)-positive dorsolateral neurons (LNd), is responsible for the E peak. Furthermore, the group of posterior dorsal neurons 1 (DN1p) is thought to also contain M and E oscillators. In this study, we found that Gal4 lines directed at the same clock neuron groups can lead to different results, underscoring the fact that activity patterns are influenced by many factors. Nevertheless, we were able to confirm previous findings that the entire network of circadian clock neurons controls M and E peaks, with the lateral neurons playing a dominant role. In addition, we demonstrate that 4 to 6 CRY-positive DN1p cells are sufficient to generate M and E peaks in light-dark cycles and complex free-running rhythms in constant darkness. Ultimately, our detailed screening could serve as a catalog to choose the best Gal4 lines that can be used to rescue per in specific clock neurons. 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=ReinhardNils en-aut-sei=Reinhard en-aut-mei=Nils kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FukudaAyumi en-aut-sei=Fukuda en-aut-mei=Ayumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KatohShun en-aut-sei=Katoh en-aut-mei=Shun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=RiegerDirk en-aut-sei=Rieger en-aut-mei=Dirk 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= en-aut-name=YoshiiTaishi en-aut-sei=Yoshii en-aut-mei=Taishi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of W?rzburg 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, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of W?rzburg kn-affil= affil-num=6 en-affil=Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of W?rzburg kn-affil= affil-num=7 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=period kn-keyword=period en-keyword=GAL4-UAS kn-keyword=GAL4-UAS en-keyword=clock neuron kn-keyword=clock neuron en-keyword=activity rhythm kn-keyword=activity rhythm en-keyword=two-oscillator model kn-keyword=two-oscillator model 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=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