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facultative diapause

Li Zhu, Zhong Tian, Shuang Guo, Wen Liu, Fen Zhu, Xiao-Ping Wang
Many organisms have evolved a series of adaptions, such as dormancy or diapause in insects that enable them to withstand seasonally adverse conditions. In insects, photoperiodic signals received during the diapause induction phase have irreversible effect on diapause initiation. Insects continue to be exposed to diapause-inducing photoperiod after the diapause induction phase during diapause preparation before they enter diapause. However, how photoperiodic signals experienced during the diapause preparation phase (DPP) regulate diapause remains largely unclear...
November 10, 2018: Insect Biochemistry and Molecular Biology
Liang Deng, Chunjin Li, Lu Chen, Yuliang Liu, Rong Hou, Xu Zhou
Embryonic diapause occurs in over 130 species of mammals. In embryonic diapause, there is a reversible cessation phase in embryo development and subsequent reactivation and continuation of development with no adverse effects. This allows animals to prolong gestation and give birth to offspring at a more favorable time from a survival perspective. Embryonic diapause is divided into two types: facultative diapause which is induced by physiological conditions and obligate diapause which is induced by season of the year...
November 2018: Animal Reproduction Science
Nina Gerber, Hanna Kokko
Natural populations often experience environments that vary across space and over time, leading to spatio-temporal variation of the fitness of a genotype. If local conditions are poor, organisms can disperse in space (physical movement) or time (dormancy, diapause). Facultatively sexual organisms can switch between asexual and sexual reproduction, and thus have a third option available to deal with maladaptedness: they can engage in sexual reproduction in unfavourable conditions (an 'abandon-ship' response)...
October 5, 2018: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
Andressa Caporale, Helena Piccoli Romanowski, Nicolás Oliveira Mega
Diapause is modulated by genetic responses to some environmental cues. The most common stimulus to trigger diapause is photoperiod, but temperature and humidity can also be important. Subtropical grasslands insects are overexposed to seasonality and can use diapause as strategy to overcome harsh conditions, avoiding freezing winter temperatures and drought summer conditions. Here, we investigate if photoperiod, temperature, and humidity can induce and terminate dormancy using the model Euryades corethrus, a butterfly from Pampa that diapause as pupae...
April 2017: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
Aurélien Richaud, Gaotian Zhang, Daehan Lee, Junho Lee, Marie-Anne Félix
To study the interplay of rare outcrossing and metapopulation structure, we focus on the nematode Caenorhabditis elegans Its remarkably low outcrossing rate is at the extreme end of the spectrum for facultative selfing organisms. At the demographic level, C. elegans natural populations undergo boom and bust dynamics on ephemeral resources, with the dauer diapause larva acting as the dispersal form. Here we investigate the small-scale genetic structure of C. elegans populations in two localities over several years, using 2b restriction-associated DNA sequencing of nearly 1000 individuals...
February 2018: Genetics
J Rozsypal, M Moos, S G Goto
The bean bug (Riptortus pedestris) is a pest of soybeans and other legumes in Japan and other Asian countries. It enters a facultative adult diapause on exposure to short days. While photoperiodism and diapause are well understood in R. pedestris, knowledge of cold tolerance is very limited, as is information on the effect of diapause on cold tolerance. We examined the effect of photoperiod, cold acclimation, and feeding status on cold tolerance in R. pedestris. We found that cold acclimation significantly increased survival at -10°C in both long- and short-day adult R...
August 2018: Bulletin of Entomological Research
Martin Schebeck, E Matthew Hansen, Axel Schopf, Gregory J Ragland, Christian Stauffer, Barbara J Bentz
Diapause, a strategy to endure unfavourable conditions (e.g. cold winters) is commonly found in ectothermic organisms and is characterized by an arrest of development and reproduction, a reduction of metabolic rate, and an increased resistance to adversity. Diapause, in addition to adaptations for surviving low winter temperatures, significantly influences phenology, voltinism and ultimately population growth. We review the literature on diapause and overwintering behaviour of two bark beetle species that affect spruce-dominated forests in the northern hemisphere, and describe and compare how these strategies can influence population dynamics...
September 2017: Physiological Entomology
Kévin Tougeron, George Hraoui, Cécile Le Lann, Joan van Baaren, Jacques Brodeur
Organisms often live in unpredictable environments and have to adopt life history strategies that optimize their fitness under these conditions. According to bet-hedging theory, individuals can reduce variation in fitness outcomes by investing in different strategies at the same time. For arthropods, facultative summer diapause enables survival during dry and hot periods of the year, and can be triggered by a decrease in resource abundance. However, the effect of resource depletion on diapause induction has never been disentangled from the effect of the perception of the presence of competitors...
June 15, 2017: Insect Science
Jeffrey L Feder, Uwe Stolz, Kristin M Lewis, William Perry, Joseph B Roethele, Allan Rogers
Host plant-associated fitness trade-offs are central to models of sympatric speciation proposed for certain phytophagous insects. But empirical evidence for such trade-offs is scant, which has called into question the likelihood of nonallopatric speciation. Here, we report on the second in a series of studies testing for host-related selection on pupal life-history characteristics of apple- (Malus pumila L.) and hawthorn- (Crataegus mollis L. spp.) infesting races of the Tephritid fruit fly, Rhagoletis pomonella (Walsh)...
December 1997: Evolution; International Journal of Organic Evolution
Satoshi Hiroyoshi, Gadi V P Reddy, Jun Mitsuhashi
We investigated the effects of juvenile hormone analogue (methoprene) and 20-hydroxyecdysone on female and male reproduction in a nymphalid butterfly, Polygonia c-aureum. This butterfly has a facultative adult diapause controlled by the corpora allata and brain. Methoprene seems to terminate reproductive diapause, although transplantation experiments indicate that the activity of the corpora allata does not affect male mating behavior Endo (Dev Growth Differ 15:1-10, 1973a), suggesting that the brain may be involved in diapause...
August 2017: Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology
Dimitrios Kontogiannatos, Theodoros Gkouvitsas, Anna Kourti
To obtain clues to the link between the molecular mechanism of circadian and photoperiod clocks, we have cloned the circadian clock gene cycle (Sncyc) in the corn stalk borer, Sesamia nonagrioides, which undergoes facultative diapause controlled by photoperiod. Sequence analysis revealed a high degree of conservation among insects for this gene. SnCYC consists of 667 amino acids and structural analysis showed that it contains a BCTR domain in its C-terminal in addition to the common domains found in Drosophila CYC, i...
June 2017: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
Sigfrid Ingrisch
The effect of temperature on embryonic development, voltinism, and hatching was studied in the laboratory in eggs of 21 Central and Southeastern European Tettigoniidae species. In most species, the embryo has to arrive at a postkatatrepsis stage prior to the onset of cold to be able to hatch in the following spring. The rate of embryonic development differs: quickly developing species need 4 weeks at 24°C (prior to cold) and almost all eggs hatch after the first cold treatment, slowly developing species would need 8-12 weeks to do the same...
November 1986: Oecologia
W Wipking
Zygaena trifolii is a "long-day insect" with temperature-dependent photoperiodic responses. All larval instars are sensitive to photoperiod; however, diapause may occur at the third larval stage or any subsequent larval instars. There were quantitative differences within populations in the threshold photoperiod for diapause induction. The diapause response was polymorphic, so that larvae might enter diapause at different instars under the same culture conditions. Furthermore, decreasing photoperiods below a critical daylength shifted the diapausing instar towards earlier stages...
December 1988: Oecologia
J Claret, Y Carton
The strain of Cothonaspis boulardi originating from a field collection at Guadeloupe (16° lat. N-West Indies) exhibits a facultative diapause that occurs at the final larval instar. The diapause was induced by low temperature (17.5° C) and was inhibited at 25° C. Diapause was independent of photoperiod. The termination of diapause was hastened in about 10 days by exposing larvae to a temperature of 25° C. Although a succession of sufficient cold days for diapause occurs only rarely in the collection area (Petit-Bourg), at higher elevations within 20 km of Petit-Bourg conditions that could induce diapause occur annually...
April 1980: Oecologia
Christer Solbreck
Neacoryphus bicrucis hibernates in the adult stage and exhibits a facultative reproductive diapause. Constant photoperiods of the durations encountered in the field do not evoke the diapause response but Shortening of the photoperiods does, providing the decrease in daylength is of a certain length and occurs within a certain photoperiodic interval. The sensitive stages are larval instars II to V. The percentage of diapausing bugs increases as temperature is lowered.It is suggested that the response to daylength shortening in N...
October 1979: Oecologia
Sigfrid Ingrisch
Developing eggs of Metrioptera roeseli HGB. have an obligate "embryonic" diapause in stage 23 and a facultative "initial" diapause in stage 4. Initial diapause is lacking when the ovipositing females are kept at long day photoperiod (LD 16/8), but is induced at LD 14/10 and LD 8/16. When natural light conditions are given in the laboratory, the females mostly lay diapausing eggs from the end of August onwards. In eggs without initial diapause, a larger number of embryos reach a stage, in which the embryonic diapause can be broken by chilling, only at favorable temperature (4 weeks at 24°C or 8 at 18°C) and in contact with water before the first winter...
February 1984: Oecologia
Hugh Dingle
Oncopeltus fasciatus exhibits a facultative reproductive diapause which is triggered by short photoperiods. The duration of the triggering photoperiod (the "critical photoperiod") is a function of the environmental conditions under which populations are reared. Some individuals are apparently sensitive to critical photoperiods in the early instars, but maximum sensitivity, indicated by 100% diapause, occurs in the late 5th instar during development of the pharate adult. Sixty per cent retain sensitivity into the first five days of adulthood...
March 1974: Oecologia
W Wipking
The onset of larval diapause in the burnet moth Zygaena trifolii is clearly characterized by the larva molting into a specialized dormant morph. In a potentially bivoltine Mediterranean population (Marseille) two types of diapause can occur within 1 year: firstly, a facultative summer diapause of 3-10 weeks, and secondly, an obligate winter diapause, which can be lengthened by a period of thermal quiescence to several months in temperatures of ≤5°C. For the first time, three successive physiological periods have been experimentally distinguished within an insect dormancy (between onset of diapause and molting to the next non-diapause stage), using chilling periods of 30-180 days at 5°C, and varying conditions of photoperiod and temperature...
May 1995: Oecologia
Dimitrios Kontogiannatos, Theodoros Gkouvitsas, Anna Kourti
To obtain clues to the link between the molecular mechanism of circadian and photoperiod clocks, we cloned two circadian clock genes, period (per) and timeless (tim) from the moth Sesamia nonagrioides, which undergoes facultative diapause controlled by photoperiod. Sequence analysis revealed a high degree of conservation among the compared insects fοr both genes. We also investigated the expression patterns of per and tim in brains of larvae growing under 16L:8D (long days), constant darkness (DD) and 10L:14D (short days) conditions by qPCR assays...
January 2017: Archives of Insect Biochemistry and Physiology
Claus-Peter Stelzer, Jussi Lehtonen
Facultative sex combines sexual and asexual reproduction in the same individual (or clone) and allows for a large diversity of life-history patterns regarding the timing, frequency and intensity of sexual episodes. In addition, other life-history traits such as a diapause stage may become linked to sex. Here, we develop a matrix modelling framework for addressing the cost of sex in facultative sexuals, in constant, periodic and stochastically fluctuating environments. The model is parametrized using life-history data from Brachionus calyciflorus, a facultative sexual rotifer in which sex and diapause are linked...
October 19, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
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