The circadian and photoperiodic clock of the pea aphid

Journal of Comparative Physiology A, Год журнала: 2023, Номер 210(4), С. 627 - 639

Опубликована: Июль 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.

Язык: Английский

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The population genetics of partial diapause, with applications to the aestivating malaria mosquito Anopheles coluzzii

Molecular Ecology Resources, Год журнала: 2024, Номер 24(4)

Опубликована: Март 21, 2024

Abstract Diapause, a form of dormancy to delay or halt the reproductive development during unfavourable seasons, has evolved in many insect species. One example is aestivation, an adult‐stage diapause enhancing malaria vectors' survival dry season (DS) and their re‐establishment next rainy (RS). This work develops novel genetic approach estimate number proportion individuals undergoing diapause, as well breeding sizes two using signals from temporal allele frequency dynamics. Our modelling shows magnitude drift dampened at early RS when previously aestivating reappear. Aestivation severely biases effective population size (), leading overestimation DS by across 1 year, where proportion. We find sampling three consecutive seasons starting sufficient for parameter estimation, perform extensive simulations verify our derivations. method does not require dormant state, biggest challenge most studies. illustrate applying it published data set Anopheles coluzzii mosquitoes Thierola, Mali. expected evolutionary implications are applicable any species which fraction diapauses more than one generation, difficult impossible sample that stage.

Язык: Английский

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Altered circadian rhythm, sleep, and rhodopsin 7 –dependent shade preference during diapause in Drosophila melanogaster

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(27)

Опубликована: Июнь 25, 2024

To survive adverse environments, many animals enter a dormant state such as hibernation, dauer, or diapause. Various Drosophila species undergo adult reproductive diapause in response to cool temperatures and/or short day-length. While flies are less active during diapause, it is unclear how environmental conditions affect circadian rhythms and sleep. Here we show that diapause-inducing temperatures, melanogaster exhibit altered activity profiles, including severely reduced morning an advanced evening peak. Consequently, the have single peak at time similar when nondiapausing take siesta. Temperatures ≤15 °C, rather than photoperiod, primarily drive this behavior. At rapidly deep-sleep lacks sleep cycles of higher require high levels stimulation for arousal. Furthermore, 25 prefer siesta shade, preference virtually eliminated 10 °C. Resting shade driven by aversion blue light sensed Rhodopsin 7 outside eyes. Flies °C neuronal markers elevated pressure, increased expression Bruchpilot Ca 2+ R5 ellipsoid body neurons. Therefore, pressure might overcome aversion. Thus, same cause arrest, preserve germline stem cells, extend lifespan, D. prone deep dramatically altered, yet rhythmic, daily patterns.

Язык: Английский

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Neural mechanism of circadian clock-based photoperiodism in insects and snails

Journal of Comparative Physiology A, Год журнала: 2023, Номер 210(4), С. 601 - 625

Опубликована: Авг. 18, 2023

Abstract The photoperiodic mechanism distinguishes between long and short days, the circadian clock system is involved in this process. Although necessity of genes for responses has been demonstrated many species, how contributes to mechanisms remains unclear. A comprehensive study, including functional analysis relevant physiology their expressing cells, necessary understand molecular cellular mechanisms. Since Drosophila melanogaster exhibits a shallow photoperiodism, have studied non-model starting with brain microsurgery neuroanatomy, followed by genetic manipulation some insects. Here, we review discuss involvement terms neural networks We also recent advances underlying insects snails, additionally systems whose photoperiodism hardly addressed yet. Brain neurosecretory insulin-like peptide / diuretic hormone44- pars intercerebralis neurones bean bug Riptortus pedestris caudo-dorsal cell hormone -expressing cells snail Lymnaea stagnalis , both promote egg laying under electrical excitability attenuated medium which reduces oviposition. are mediated glutamate control gene period . Thus, now able assess response activity investigate upstream mechanisms, that is, counter.

Язык: Английский

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Neuroendocrine Regulation of Reproductive Dormancy in the Fruit Fly Drosophila melanogaster: A Review of Juvenile Hormone-Dependent Regulation

Frontiers in Ecology and Evolution, Год журнала: 2021, Номер 9

Опубликована: Сен. 23, 2021

Animals can adjust their physiology, helping them survive and reproduce under a wide range of environmental conditions. One the strategies to endure unfavorable conditions such as low temperature limited food supplies is dormancy. In some insect species, this may manifest reproductive dormancy, which causes organs be severely depleted unsuitable for reproduction. Reproductive dormancy in insects induced by reduction juvenile hormones synthesized corpus allatum (pl. corpora allata ; CA) response winter-specific cues, temperatures short-day length. recent years, significant progress has been made study dormancy-inducing dependent on CA control mechanisms Drosophila melanogaster . This review summarizes D. discusses implications future studies particularly focusing hormone-dependent regulation.

Язык: Английский

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