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Seasons and Photoperiodism
Published in Sue Binkley, Biological Clocks, 2020
A response of an organism to the changes in day and night length is a photoperiodic response. The rationale that is offered is that there are adaptive advantages in being able to anticipate and make best use of the advantages, particularly of spring and summer for raising young, and to avoid the harsh winter conditions.
Effects of Environmental Factors on the Endocrine System
Published in George H. Gass, Harold M. Kaplan, Handbook of Endocrinology, 2020
To study the possible seasonality in human reproduction, we must understand the mechanisms involved in seasonal breeders with clear annual rhythmicity. Seasonality is closely linked to photoperiodism with a strong genetic basis. There are significant species differences in photoperiodic responsiveness with a varying degree of seasonality. Exposure to different environmental conditions is the main driving force for the evolution of seasonality. Domestication, for example, is known to reduce seasonality.
Eating Disorders and Treatment
Published in Emily Crews Splane, Neil E. Rowland, Anaya Mitra, Psychology of Eating, 2019
Emily Crews Splane, Neil E. Rowland, Anaya Mitra
This model is not only task-related but, because birds are seasonal breeders, will be associated with specific day length (photoperiod) indicative of the season. If animals show physiological and behavioral changes in different seasons, they are said to be photoperiodic. There are other photoperiod-related changes in food intake. Many species eat less in the winter when days are short and lose substantial body weight (e.g., 20%; Iverson & Turner, 1974), and, like the incubating birds, this occurs even in captivity when food is readily available. In the natural environment, food tends to be less abundant during the winter, and expending large amounts of energy in unsuccessful foraging is a poor survival strategy. The physiological suppression of hunger then has an adaptive function. Another example is in rutting deer (Yoccoz et al., 2002): The males lose 10% to 15% of their body weight during rutting season, even though there is plenty of grass around; in contrast, females do not lose weight.
Photoperiodic adaptation of aanat and clock gene expression in seasonal populations of Daphnia pulex
Published in Chronobiology International, 2023
Anke Schwarzenberger, Patrick Bartolin, Alexander Wacker
We expected a switch-back to higher gene expression (as in spring) from summer to autumn because photoperiods shorten after summer solstice. Actually, this could be observed for timeless for both autumn subpopulations, and for clock, period, aanat 1 and 3 in one of the autumn subpopulations while the other autumn subpopulation showed a similar or lower (period) gene expression as in summer. This not only means that we captured the switch from a summer population adapted to long photoperiods to an autumn population that is in the course to adapt to shorter photoperiods; we also found that the single genes adapt independent of each other (i.e. in different subpopulations) to a change in photoperiod. Since the change of seasons happens with a slow change in photoperiod lengths, also the succession of clones adapted to those different photoperiods is not a harsh selection process but is slow and takes place in intermediate stages (cf. the bimodal pattern). This also explains why the subpopulations of autumn and summer showed a gene expression pattern comparable to the summer population for cryptochrome2 and aanat 5 whereas the other clock genes already show an average gene expression higher than in summer.
Perinatal photoperiod associations with diabetes and chronotype prevalence in a cross-sectional study of the UK Biobank
Published in Chronobiology International, 2021
Philip Lewis, Peter Morfeld, Judith Mohren, Martin Hellmich, Thomas C. Erren
A previous epidemiological study indicated possible differential “dose” responses (Lewis et al. 2020a). Furthermore, extreme short photoperiods (ESPs, <8 h) are potentially confounded by unmeasured artificial light that may have a more dominant circadian role when daylight is extremely short. Similarly, extreme long photoperiods (ELPs, >16 h) are potentially confounded by measures taken against light during biological nights. Thus, we distinguish in analyses between individuals who experience one or more ESPs or ELPs, and non-extreme photoperiods (NEPs) to consider a varying degree of unmeasured confounding or possible differential “dose” response. In other words, we defined three groups based on photoperiods experienced in the 3rd trimester and 3 months post birth time windows: (1) NEP (i.e., NEPs-only within the time window of interest), (2) ESP (individuals who experience at least 1 ESP in the time window of interest), and (3) ELP (individuals who experience at least 1 ELP in the time window of interest).
Effects of prolonged night-time light exposure and traffic noise on the behavior and body temperature rhythmicity of the wild desert rodent, Gerbillus tarabuli
Published in Chronobiology International, 2021
Salem Mamoun Issad, Nadir Benhafri, Khalid El Allali, Hicham Farsi, Saliha Ouali-Hassenaoui, Aicha Dekar-Madoui
The continued expansion of human activity leads to growing urban sprawl, causing environmental degradation and inducing dramatic changes in the wildlife habitats with specifically two main externally imposed environmental factors: light pollution and traffic noise, described as a multisensory pollution (Dominoni et al. 2020). Specialists have registered a 6% annual increase in worldwide artificial lighting due to the increase of the human infrastructure and activity (Hölker et al. 2010). Prolonged exposure to such artificial lighting has certainly had dramatic consequences on many wild species and ecosystems. Several studies demonstrate that imposing artificial light at night in rodents significantly disturbs the circadian rhythms of locomotor activity, body temperature (Tb), and hormones and affects the molecular mechanisms of the photoperiodic response underlying the melatonin processing pathway (Fonken et al. 2009; Tomoko et al. 2014). Other consequences were also reported, such as acceleration of aging, tumor genesis in rats (Irina et al. 2013), development of depressive like disorder (Fonken et al. 2012), and anxiety-like behavior (Tapia-Osorio et al. 2013).