A clock for all seasons

Journal of Comparative Physiology A, Journal Year: 2024, Volume and Issue: 210(4), P. 473 - 480

Published: June 19, 2024

Abstract Circadian clocks play an essential role in adapting locomotor activity as well physiological, and metabolic rhythms of organisms to the day-night cycles on Earth during four seasons. In addition, they can serve a time reference for measuring day length adapt advance annual changes environment, which be particularly pronounced at higher latitudes. The physiological responses are also known photoperiodism. This special issue Journal Comparative Physiology A aims account diurnal photoperiodic adaptations by presenting collection ten review articles, five original research three perspective pieces. contributions include historical accounts, circadian clock models, epigenetic, molecular, neuronal mechanisms seasonal adaptations, latitudinal differences studies wild that address challenges global change.

Language: Английский

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Bimodal Patterns of Locomotor Activity and Sleep in Drosophila: A Model for Their Simulation

Nature and Science of Sleep, Journal Year: 2025, Volume and Issue: Volume 17, P. 115 - 127

Published: Jan. 1, 2025

Two previously proposed modelling approaches to explain the bimodal pattern of activity and/or sleep in Drosophila melanogaster are based on 1) concept morning and evening oscillators underlying peaks evening, respectively, 2) two cycles buildup decay pressure, gated only by circadian oscillator. Previously, we simulated 24-h alertness-sleepiness curves humans using a model postulating modulation phases (wake sleep) homeostatic processes. Here, tested whether similar could be applied simulate rhythm fly locomotor sleep. To obtain typical for simulations, sample 4263 individual were subjected principal component analysis. It yielded three components, which explained more than 70% variations these curves. We calculated scores 1st, 2nd, 3rd components sample-averaged found that always characterized with varying sizes timings. They can fitted proposing variation some parameters processes reflecting rhythmicity drive wake 12-h Postulation separate is not necessary melanogaster.

Language: Английский

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Correlation between circadian and photoperiodic latitudinal clines in Drosophila littoralis

Open Biology, Journal Year: 2025, Volume and Issue: 15(3)

Published: March 1, 2025

Insects can survive harsh conditions, including Arctic winters, by entering a hormonally induced state of dormancy, known as diapause. Diapause is triggered environmental cues such shortening the photoperiod (lengthening night). The time entry into diapause depends on latitude insects' habitat, and this applies even within species: populations living at higher latitudes enter earlier in year than lower latitudes. A long-standing question biology whether internal circadian clock, which governs daily behaviour serves reference clock to measure night length, shows similar latitudinal adaptations. To address question, we examined onset various behavioural molecular parameters cosmopolitan fly, Drosophila littoralis, species distributed throughout Europe from Black Sea (41° N) regions (69° N). We found that all showed same correlation with critical length for induction. conclude has adapted may result observed differences

Language: Английский

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The circadian and photoperiodic clock of the pea aphid

Journal of Comparative Physiology A, Journal Year: 2023, Volume and Issue: 210(4), P. 627 - 639

Published: July 24, 2023

The pea aphid, Acyrthosiphon pisum, is a paradigmatic photoperiodic species that exhibits remarkable annual life cycle, which tightly coupled to the seasonal changes in day length. During spring and summer, characterised by longer days, aphid populations consist exclusively of viviparous females reproduce parthenogenetically. When autumn comes days shorten, aphids switch their reproductive mode generate males oviparous sexual females, mate produce cold-resistant eggs overwinter survive unfavourable season. While responses have been well described, nature timing mechanisms underlie length discrimination are still not completely understood. Experiments from 1960's suggested rely on an 'hourglass' clock measuring elapsed time during dark night accumulating biochemical factor, reaches critical threshold at certain triggers reproduction mode. However, can also be attributed strongly dampened circadian clock. Recent studies uncovered molecular components location brain revealed it connected neurohormonal system controlling reproduction. We provide overview putative control aphids, photoreceptors involved this process neuroendocrine system.

Language: Английский

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Erwin Bünning and Wolfgang Engelmann: establishing the involvement of the circadian clock in photoperiodism

Journal of Comparative Physiology A, Journal Year: 2024, Volume and Issue: 210(4), P. 481 - 493

Published: May 28, 2024

In 1936, Erwin Bünning published his groundbreaking work that the endogenous clock is used to measure day length for initiating photoperiodic responses. His publication triggered years of controversial debate until it ultimately became basic axiom rhythm research and theoretical pillar chronobiology. Bünning's thesis frequently quoted in articles this special issue on subject "A all seasons". However, nowadays only few people know detail about experiments almost nobody knows contribution former doctoral student, Wolfgang Engelmann, theory because most topic German. The aim review give an overview important at time, including Engelmann's thesis, which he demonstrated importance circadian flower induction Flaming Katy, Kalanchoë blossfeldiana, but not Red Morning Glory, Ipomoea coccinea.

Language: Английский

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Neuropeptide Dynamics Coordinate Layered Plasticity Mechanisms Adapting Drosophila Circadian Behavior to Changing Environment.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 18, 2024

Abstract The Drosophila brain contains distinct sets of circadian oscillators responsible for generating the morning and evening bouts locomotor activity, giving rise to a bimodal rest-activity pattern in light-dark cycles. We lack mechanistic understanding how environmental changes reshape this daily profile pattern. Here, we uncover seasonal switch mechanism that remodels bout activity. Under summer-like conditions, an environment favored by fruit flies temperate climates, levels PDF neuropeptide diminish, triggering cascade. Lowered PDFR signaling disinhibits GSK3/SGG advance output. Upon sensing loss, neural activity weakens DN1p-SIF circuit, promoting afternoon rest; leading earlier appearance peak. At same time, functional connections from DN1p LNd strengthen, consequently handing over pacemaker role DN1ps. Taken together, our findings elucidate environment-induced tip balanced output clock network, aligning rhythms with time. Neuropeptide-driven parallel adjustment circuitry protein functioning likely represents conserved strategy across animal species, enabling them adapt their behavior throughout year.

Language: Английский

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Variation in photoperiod response corresponds to differences in circadian light sensitivity in northern and southern Nasonia vitripennis lines

Journal of Comparative Physiology A, Journal Year: 2023, Volume and Issue: 210(4), P. 667 - 676

Published: Oct. 18, 2023

Abstract The circadian clock times physiological and behavioural processes resets on a daily basis to synchronize with the environment. involvement of in photoperiodic time measurement synchronising annual rhythms is still under debate different models have been proposed explaining their integration. Insects overcome unfavourable conditions diapause, form dormancy. A latitudinal cline diapause induction parasitoid wasp Nasonia vitripennis as well difference light sensitivity between north south provide us additional evidence that system involved latitude-specific seasonality drives adaptive evolution photoperiodism partly through adaptation responses system. We tested range T-cycles photoperiods found short all northern line but southern line, only occurred close 24 h. Due lower wider distribution phase angles entrainment can be expected at specific T-cycle duration, while will decrease. Taking these oscillator properties into account, our data explained by an external coincidence model involving single light-sensitive timing .

Language: Английский

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Characterization of pre-diapause phase in the northern Drosophila species D. ezoana

Journal of Comparative Physiology A, Journal Year: 2024, Volume and Issue: 210(6), P. 901 - 908

Published: June 25, 2024

Language: Английский

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