Physiology of Insect Diapause. Xiv. An Endocrine Mechanism for the Photoperiodic Control of Pupal Diapause in the Oak Silkworm, Antheraea Pernyi

Williams, Carroll M.; Adkisson, Perry L.

doi:10.2307/1539252

Cited by 208 publications

(59 citation statements)

References 15 publications

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“…But exceptions to these generalizations occur in several species. In Chinese tasar moth (Antheraea pernyi), critical photoperiod for diapause induction and termination are very similar [33]. While in other insects where natural populations were studied in field (Meleoma signoretti and mosquito (Wyeomyia smithii)), the two values of day length differed [30].…”

Section: Response Curves and Critical Photoperiodmentioning

confidence: 99%

Insect Diapause: A Review

Gill¹,

Goyal²,

Chahil³

2017

JAST-A

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Diapause is defined as a period of suspended development in insects and other invertebrates during unfavorable environmental conditions. Diapause is commonly confused with term "quiescence" as both are dormant development stages. Here this paper aimed to review the research work done on different aspects of diapause. Attempt was made to explain definitions of diapause, incidence, stages and termination of diapause, genetic control, factors affecting diapauses, including temperature, photoperiod, moisture and food, etc..

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Section: Response Curves and Critical Photoperiodmentioning

confidence: 99%

Insect Diapause: A Review

Gill¹,

Goyal²,

Chahil³

2017

JAST-A

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“…In the cricket Gryllus bimaculatus, only the dorsocaudal ommatidia of the compound eye are involved (Tomioka & Yukizane, 1997). In only a few species have photorecep tors for both photoperiodic responses and circadian entrainment been localized: both may be in the brain (Williams & Adkisson, 1964;Truman, 1972;Cymbor owski et al, 1994;Saunders & Cymborowski, 1996) or both in the eyes (Nakamura & Hodkova, 1998). Even so, the wider differences reviewed above, the further local ization of receptors described in some species, and differ ences in specific responses to photoperiod suggest that even circadian and photoperiodic receptors within the same structure may be different from each other and, per haps, from one species to the next.…”

Section: Inputsmentioning

confidence: 99%

Studying insect photoperiodism and rhythmicity: Components, approaches and lessons

Danks¹

2003

Eur. J. Entomol.

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Abstract.Components of daily and seasonal timing systems in insects are reviewed. Photoperiod indicates seasonal position reliably, but signals can be much modified by habitat, latitude and season. Several receptor features and pigment systems are known, with different daily, seasonal and general functions, including differences between circadian and seasonal reception. Clocks can serve several different purposes, functioning as daily oscillators, interval timers or through successive requirements. The molecular functioning of circadian clocks is best known, but even so there is considerable complexity and diversity and much remains to be discovered. We know relatively little about the internal states that provide information for timed responses (such as the photoperi odic "counter"), about the central controlling mechanism, or about the effectors that transmit output signals. Nevertheless, temporal responses serve a very great range of purposes in insects, and the reported complexity in all of the components of timing systems reflects complex ecological needs across daily and seasonal intervals. The variety of components and the complexity of interactions reported (even within species), as well as the diversity of such elements as photosensitive pigments, molecular clock function and potential neurotransmitters, suggests that -unlike some earlier expectations -there is no single master clock for all timing functions in insects.Insect photoperiodism and rhythmicity have been studied by both observational or direct approaches (examination of system ele ments or devices, and qualities such as survival), and by inferential or indirect approaches (such as interpretation of various responses to photoperiod, modelling, and estimating fitness). Many students work with only one approach, but the power of different approaches is not equal, and knowledge at one level may not give answers at another. These difficulties tend to limit our under standing of the linkages among components.This overview suggests several lessons for the study of photoperiodism and rhythmicity. There are multiple elements, complex integration and a diversity of clocks, showing that different processes serve different purposes. The diversity of findings also results from the fact that different investigative approaches, which depend on the question being asked and on the perspective of the investi gator, can influence the outcome of the investigation. Given these complexities, I believe that the key to interpreting photoperiodic and circadian responses is their ecological value. Notwithstanding the interest of timing mechanisms or their parts and of specific responses, daily rhythms and seasonal timing are best understood through the essential context provided by the ecological demands on the actual organisms under study.

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“…The pupal diapause of Pernyi can be terminated by exposing the animals to long-day photoperiod conditions (17L: 7D). This response is greatly accelerated after several months of preliminary chilling (8,9). Routinely, pupae chilled for at least 4 weeks were placed in the 17L: 7D regimen at 260C until adult development began.…”

Section: Methodsmentioning

confidence: 99%

Hour-Glass Behavior of the Circadian Clock Controlling Eclosion of the Silkmoth Antheraea pernyi

Truman

1971

Proc. Natl. Acad. Sci. U.S.A.

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The emergence of the Pernyi silkmoth from the pupal exuviae is dictated by a brain-centered, photosensitive clock. In continuous darkness the clock displays a persistent free-running rhythm. In photoperiod regimens the interaction of the clock with the daily lightdark cycle produces a characteristic time of eclosion. But, in the majority of regimens (from 23L:ID to 4L:20D), the eclosion clock undergoes a discontinuous "hourglass" behavior. Thus, during each daily cycle, the onset of darkness initiates a free-running cycle of the clock. The next "lights-on" interrupts this cycle and the clock comes to a stop late in the photophase. The moment when the Pernyi clock stops signals the release of an eclosion-stimulating hormone and is demonstrated to be a function of the time when the free-running cycle is interrupted by lights-on. Moreover, the width (duration) of the eclosion peak in a photoperiod is shown to be dependent upon the length of the dark phase, and, consequently, upon the amount of the free-running cycle that is completed. This relationship demonstrates that the free-running cycle may be divided into two parts. The attainment of maximal accuracy (and thus the narrowest eclosion peak) is dependent upon the completion of only the first 2 hr of the free-running cycle. The completion of succeeding portions of the cycle, while having an effect upon the time of eclosion, no longer affects the accuracy of the clock. A mechanistic model of the eclosion clock is presented.The capacity to "keep-time" appears to be ubiquitous among organisms (1). Among the most striking examples of this temporal organization are circadian rhythms-events which in the absence of external cues occur at intervals of approximately 24 hr. The emergence (eclosion, ecdysis) of the fruit fly (Drosophila pseudoobscura) from the puparium is one such event that has received considerable attention during the past 15 years (2-5). Eclosion in this case terminates an intricate series of developmental processes that transform the maggot into the fly. Although the fly may complete development at any time of the day, there is only a certain period during which it may emerge. Thus, eclosion is said to be "gated" (5).Studies of the role of photoperiod in the gating of eclosion have pinpointed several important properties of the controlling clock. Thus, when populations of flies are transformed from a photoperiod into continuous darkness, they display a persistent "free-running" rhythm of eclosion. When this freerunning population is exposed to a flash of light, the time of eclosion is either advanced or delayed and a new rhythm is. Abbreviation: #L: #D, a light-dark regimen that alternates the specified number of hours of light with the specified hours of darkness. 595 thereby established (3). The phase assumed by the new rhythm proves to be a function of the time at which the flash is administered during the free-running cycle. The experimentally determined function permits one to plot a "phase-response curve." For our present purposes, the p...

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Physiology of Insect Diapause. Xiv. An Endocrine Mechanism for the Photoperiodic Control of Pupal Diapause in the Oak Silkworm, Antheraea Pernyi

Cited by 208 publications

References 15 publications

Insect Diapause: A Review

Insect Diapause: A Review

Studying insect photoperiodism and rhythmicity: Components, approaches and lessons

Hour-Glass Behavior of the Circadian Clock Controlling Eclosion of the Silkmoth Antheraea pernyi

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