timeless2 plays an important role in reproduction and circadian rhythms in the cricket Gryllus bimaculatus

Nose, Motoki; Tokuoka, Atsushi; Bando, Toshikazu; Tomioka, Kenji

doi:10.1016/j.jinsphys.2017.12.007

Cited by 9 publications

(3 citation statements)

References 31 publications

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“…In the second scenario, the modulatory role of TIM-d led to its loss, excluding CRY-d from the loop and resulting in its subsequent loss. The involvement of TIM-m in the circadian clock is indicated both from mammalian models ( Barnes et al 2003 ; Kurien et al 2019 ) and insect models ( Benna et al 2010 ; Nose et al 2017 ), albeit its role is not established in detail. The third type of path observed in evolution involves the loss of the per gene.…”

Section: Discussionmentioning

confidence: 99%

Loss of Timeless Underlies an Evolutionary Transition within the Circadian Clock

Kotwica‐Rolinska

Chodáková

Smýkal

et al. 2021

Molecular Biology and Evolution

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Most organisms possess time-keeping devices called circadian clocks. At the molecular level, circadian clocks consist of transcription-translation feedback loops. Although some components of the negative transcription-translation feedback loop are conserved across the animals, important differences exist between typical models, such as mouse and the fruit fly. In Drosophila, the key components are PERIOD (PER) and TIMELESS (TIM-d) proteins, whereas the mammalian clock relies on PER and CRYPTOCHROME (CRY-m). Importantly, how the clock has maintained functionality during evolutionary transitions between different states remains elusive. Therefore, we systematically described the circadian clock gene setup in major bilaterian lineages and identified marked lineage-specific differences in their clock constitution. Then we performed a thorough functional analysis of the linden bug Pyrrhocoris apterus, an insect species comprising features characteristic of both the Drosophila and the mammalian clocks. Unexpectedly, the knockout of timeless-d, a gene essential for the clock ticking in Drosophila, did not compromise rhythmicity in P. apterus, it only accelerated its pace. Furthermore, silencing timeless-m, the ancestral timeless type ubiquitously present across animals, resulted in a mild gradual loss of rhythmicity, supporting its possible participation in the linden bug clock, which is consistent with timeless-m role suggested by research on mammalian models. The dispensability of timeless-d in P. apterus allows drawing a scenario in which the clock has remained functional at each step of transition from an ancestral state to the TIM-d-independent PER+CRY-mammalian system operating in extant vertebrates, including humans.

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Section: Discussionmentioning

confidence: 99%

Loss of Timeless Underlies an Evolutionary Transition within the Circadian Clock

Kotwica‐Rolinska

Chodáková

Smýkal

et al. 2021

Molecular Biology and Evolution

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“…The products of per and tim combine into PER/TIM protein heterodimers, which then localize into cell nuclei, resulting in the inhibition of transcripts through the attenuation of CLK/CYC (Yu et al, 2009). The tim gene's expression has been studied in many insect species, including Bombyx mori (Xu et al, 2011), D. melanogaster (Sehgal et al, 1994), Laodelphax striatellus (Hemiptera: Delphacidae) (Jiang et al, 2018), Gryllus bimaculatus (Danbara et al, 2010, Nose et al, 2017, Thermobia domestica (Kamae & Tomioka, 2012), and Danaus plexippus (Lepidoptera: Danaidae) (Zhu et al, 2008). These studies revealed that the biological clocks of insects are complex.…”

Section: Introductionmentioning

confidence: 99%

CRISPR/Cas9‐based knockout reveals that the clock gene timeless is indispensable for regulating circadian behavioral rhythms in Bombyx mori

et al. 2020

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Circadian rhythms, which are ubiquitous and adaptive, occur across all species, from microbes to humans, in which they organize and modify behavior and physiology. timeless (tim) is a canonical clock gene. The core composition of the Drosophila melanogaster endogenous circadian clock has been extensively investigated; however, in lepidopteran insects, including Bombyx mori, the mechanism is complicated and little is known regarding the participation of tim in the negative feedback loop responsible for behavioral activities. To arrive at a comprehensive understanding of the role of tim in the B. mori endogenous circadian clock, we exploited the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 gene editing system. We attempted to elucidate the functions of tim in the circadian clock of B. mori using Bmtim mutants. The knockouts affected two circadian behavioral activities: adult emergence and embryo hatching rhythms. Quantitative real-time polymerase chain reaction results confirmed that tim-knockouts induced relative reductions in the expression levels, and thereby the oscillation amplitudes, of Bmper and Bmclk messenger RNAs during both the photophase and scotophase. Additionally, the daily rhythmic expression of Bmdbt was upregulated in the photophase and downregulated in the scotophase in a tim-knockout. Our study reveals that tim is integral to the B. mori circadian clock and may be involved in regulating eclosion and hatching rhythms.

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“…That is, a range of time scale factors can dramatically affect the magnitude and type of physiological responses by individual insects. Examples include: (1) minutes of exposureor acclimation to abiotic factors like temperature (Macdonald et al, 2004; Weidlich et al, 2012), UV irradiation (Meng et al, 2009), low oxygen levels (Deng et al, 2018); (2) when during circadian rhythms physiological processes are investigated (Danks, 2003, 2005; Weidlich et al, 2012; Bloch et al, 2013; Suszczynska et al, 2017; Nose et al, 2018); and 3) sampling time during field seasons (Danks, 2003, 2005; Matsuda et al, 2017). Time scale factors further vary among life stages and in response to biological stress factors such as infection or parasitism (Weidlich et al, 2012; Nose et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Proximal Remote Sensing to Non-destructively Detect and Diagnose Physiological Responses by Host Insect Larvae to Parasitism

Nansen

Strand

2018

Front. Physiol.

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As part of identifying and characterizing physiological responses and adaptations by insects, it is paramount to develop non-destructive techniques to monitor individual insects over time. Such techniques can be used to optimize the timing of when in-depth (i.e., destructive sampling of insect tissue) physiological or molecular analyses should be deployed. In this article, we present evidence that hyperspectral proximal remote sensing can be used effectively in studies of host responses to parasitism. We present time series body reflectance data acquired from individual soybean loopers (Chrysodeixis includens) without parasitism (control) or parasitized by one of two species of parasitic wasps with markedly different life histories: Microplitis demolitor, a solitary larval koinobiont endoparasitoid and Copidosoma floridanum, a polyembryonic (gregarious) egg-larval koinobiont endoparasitoid. Despite considerable temporal variation in reflectance data 1–9 days post-parasitism, the two parasitoids caused uniquely different host body reflectance responses. Based on reflectance data acquired 3–5 days post-parasitism, all three treatments (control larvae, and those parasitized by either M. demolitor or C. floridanum) could be classified with >85 accuracy. We suggest that hyperspectral proximal imaging technologies represent an important frontier in insect physiology, as they are non-invasive and can be used to account for important time scale factors, such as: minutes of exposure or acclimation to abiotic factors, circadian rhythms, and seasonal effects. Although this study is based on data from a host-parasitoid system, results may be of broad relevance to insect physiologists. Described approaches provide a non-invasive and rapid method that can provide insights into when to destructively sample tissue for more detailed mechanistic studies of physiological responses to stressors and environmental conditions.

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timeless2 plays an important role in reproduction and circadian rhythms in the cricket Gryllus bimaculatus

Cited by 9 publications

References 31 publications

Loss of Timeless Underlies an Evolutionary Transition within the Circadian Clock

Loss of Timeless Underlies an Evolutionary Transition within the Circadian Clock

CRISPR/Cas9‐based knockout reveals that the clock gene timeless is indispensable for regulating circadian behavioral rhythms in Bombyx mori

Proximal Remote Sensing to Non-destructively Detect and Diagnose Physiological Responses by Host Insect Larvae to Parasitism

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