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Walsh LL, Tucker PK. Stable Isotope Values Suggest Opossums (Didelphis virginiana) at the Northern Edge of their Range do not Seasonally Molt. Northeast Nat (Steuben) 2021. [DOI: 10.1656/045.028.0101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Lisa L. Walsh
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
| | - Priscilla K. Tucker
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
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202
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Goekoop R, de Kleijn R. How higher goals are constructed and collapse under stress: A hierarchical Bayesian control systems perspective. Neurosci Biobehav Rev 2021; 123:257-285. [PMID: 33497783 DOI: 10.1016/j.neubiorev.2020.12.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 11/19/2020] [Accepted: 12/19/2020] [Indexed: 01/26/2023]
Abstract
In this paper, we show that organisms can be modeled as hierarchical Bayesian control systems with small world and information bottleneck (bow-tie) network structure. Such systems combine hierarchical perception with hierarchical goal setting and hierarchical action control. We argue that hierarchical Bayesian control systems produce deep hierarchies of goal states, from which it follows that organisms must have some form of 'highest goals'. For all organisms, these involve internal (self) models, external (social) models and overarching (normative) models. We show that goal hierarchies tend to decompose in a top-down manner under severe and prolonged levels of stress. This produces behavior that favors short-term and self-referential goals over long term, social and/or normative goals. The collapse of goal hierarchies is universally accompanied by an increase in entropy (disorder) in control systems that can serve as an early warning sign for tipping points (disease or death of the organism). In humans, learning goal hierarchies corresponds to personality development (maturation). The failure of goal hierarchies to mature properly corresponds to personality deficits. A top-down collapse of such hierarchies under stress is identified as a common factor in all forms of episodic mental disorders (psychopathology). The paper concludes by discussing ways of testing these hypotheses empirically.
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Affiliation(s)
- Rutger Goekoop
- Parnassia Group, PsyQ, Department of Anxiety Disorders, Early Detection and Intervention Team (EDIT), Netherlands.
| | - Roy de Kleijn
- Cognitive Psychology Unit, Leiden University, Netherlands
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203
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Giroud S, Habold C, Nespolo RF, Mejías C, Terrien J, Logan SM, Henning RH, Storey KB. The Torpid State: Recent Advances in Metabolic Adaptations and Protective Mechanisms †. Front Physiol 2021; 11:623665. [PMID: 33551846 PMCID: PMC7854925 DOI: 10.3389/fphys.2020.623665] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
Torpor and hibernation are powerful strategies enabling animals to survive periods of low resource availability. The state of torpor results from an active and drastic reduction of an individual's metabolic rate (MR) associated with a relatively pronounced decrease in body temperature. To date, several forms of torpor have been described in all three mammalian subclasses, i.e., monotremes, marsupials, and placentals, as well as in a few avian orders. This review highlights some of the characteristics, from the whole organism down to cellular and molecular aspects, associated with the torpor phenotype. The first part of this review focuses on the specific metabolic adaptations of torpor, as it is used by many species from temperate zones. This notably includes the endocrine changes involved in fat- and food-storing hibernating species, explaining biomedical implications of MR depression. We further compare adaptive mechanisms occurring in opportunistic vs. seasonal heterotherms, such as tropical and sub-tropical species. Such comparisons bring new insights into the metabolic origins of hibernation among tropical species, including resistance mechanisms to oxidative stress. The second section of this review emphasizes the mechanisms enabling heterotherms to protect their key organs against potential threats, such as reactive oxygen species, associated with the torpid state. We notably address the mechanisms of cellular rehabilitation and protection during torpor and hibernation, with an emphasis on the brain, a central organ requiring protection during torpor and recovery. Also, a special focus is given to the role of an ubiquitous and readily-diffusing molecule, hydrogen sulfide (H2S), in protecting against ischemia-reperfusion damage in various organs over the torpor-arousal cycle and during the torpid state. We conclude that (i) the flexibility of torpor use as an adaptive strategy enables different heterothermic species to substantially suppress their energy needs during periods of severely reduced food availability, (ii) the torpor phenotype implies marked metabolic adaptations from the whole organism down to cellular and molecular levels, and (iii) the torpid state is associated with highly efficient rehabilitation and protective mechanisms ensuring the continuity of proper bodily functions. Comparison of mechanisms in monotremes and marsupials is warranted for understanding the origin and evolution of mammalian torpor.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Caroline Habold
- University of Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France
| | - Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, ANID – Millennium Science Initiative Program-iBio, Valdivia, Chile
- Center of Applied Ecology and Sustainability, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carlos Mejías
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, ANID – Millennium Science Initiative Program-iBio, Valdivia, Chile
- Center of Applied Ecology and Sustainability, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jérémy Terrien
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d’Histoire Naturelle, Brunoy, France
| | | | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, Groningen, Netherlands
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204
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Yazhini A, Srinivasan N, Sandhya S. Signatures of conserved and unique molecular features in Afrotheria. Sci Rep 2021; 11:1011. [PMID: 33441654 PMCID: PMC7806701 DOI: 10.1038/s41598-020-79559-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 12/07/2020] [Indexed: 11/09/2022] Open
Abstract
Afrotheria is a clade of African-origin species with striking dissimilarities in appearance and habitat. In this study, we compared whole proteome sequences of six Afrotherian species to obtain a broad viewpoint of their underlying molecular make-up, to recognize potentially unique proteomic signatures. We find that 62% of the proteomes studied here, predominantly involved in metabolism, are orthologous, while the number of homologous proteins between individual species is as high as 99.5%. Further, we find that among Afrotheria, L. africana has several orphan proteins with 112 proteins showing < 30% sequence identity with their homologues. Rigorous sequence searches and complementary approaches were employed to annotate 156 uncharacterized protein sequences and 28 species-specific proteins. For 122 proteins we predicted potential functional roles, 43 of which we associated with protein- and nucleic-acid binding roles. Further, we analysed domain content and variations in their combinations within Afrotheria and identified 141 unique functional domain architectures, highlighting proteins with potential for specialized functions. Finally, we discuss the potential relevance of highly represented protein families such as MAGE-B2, olfactory receptor and ribosomal proteins in L. africana and E. edwardii, respectively. Taken together, our study reports the first comparative study of the Afrotherian proteomes and highlights salient molecular features.
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Affiliation(s)
- Arangasamy Yazhini
- Lab 103, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Narayanaswamy Srinivasan
- Lab 103, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, 560012, India.
| | - Sankaran Sandhya
- Lab 103, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, 560012, India.
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205
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MacCannell ADV, Staples JF. Elevated ambient temperature accelerates aspects of torpor phenology in an obligate hibernator. J Therm Biol 2021; 96:102839. [PMID: 33627277 DOI: 10.1016/j.jtherbio.2021.102839] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 12/08/2020] [Accepted: 01/01/2021] [Indexed: 10/22/2022]
Abstract
The thirteen-lined ground squirrel (Ictidomys tridecemlineatus) is assumed to be an obligate hibernator - commencing and terminating hibernation on a circannual rhythm, regardless of environmental conditions - but, until now, this assumption had never been fully tested. We housed three groups of captive-born ground squirrels from Aug. 2017 to Aug. 2018 under constant photoperiod (12 h L:12 h D) at 5, 16 or 25 °C, and monitored hibernation using body temperature loggers. At 5 and 16 °C all animals hibernated from autumn to spring with no differences in date of first/last torpor or duration of interbout euthermic periods (IBE), but torpor bout duration was 25% shorter at 16 °C. One of 4 animals housed at 25 °C did not hibernate. For the other three 25 °C animals, the first torpor date did not differ from the other groups, but the last torpor bout (5 Feb.) occurred almost 8 weeks earlier. These animals aroused from torpor more frequently and IBE lasted significantly longer, so the total time spent torpid was less than 50% of the other groups. Unlike the 5 or 16 °C animals, 25 °C animals re-entered torpor in late spring 2018. Taken together these data suggest that this species is an obligate hibernator, but that high ambient temperatures can accelerate the endogenous circannual hibernation rhythm.
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Affiliation(s)
- Amanda D V MacCannell
- Department of Biology, University of Western Ontario, London, ON, N6A5B8, Canada; Discovery and Translational Science Dept., University of Leeds, Leeds, LS2 9DA, United Kingdom.
| | - James F Staples
- Department of Biology, University of Western Ontario, London, ON, N6A5B8, Canada.
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206
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Eberts ER, Guglielmo CG, Welch KC. Reversal of the adipostat control of torpor during migration in hummingbirds. eLife 2021; 10:70062. [PMID: 34866575 PMCID: PMC8719877 DOI: 10.7554/elife.70062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 11/19/2021] [Indexed: 01/12/2023] Open
Abstract
Many small endotherms use torpor to reduce metabolic rate and manage daily energy balance. However, the physiological 'rules' that govern torpor use are unclear. We tracked torpor use and body composition in ruby-throated hummingbirds (Archilochus colubris), a long-distance migrant, throughout the summer using respirometry and quantitative magnetic resonance. During the mid-summer, birds entered torpor at consistently low fat stores (~5% of body mass), and torpor duration was negatively related to evening fat load. Remarkably, this energy emergency strategy was abandoned in the late summer when birds accumulated fat for migration. During the migration period, birds were more likely to enter torpor on nights when they had higher fat stores, and fat gain was positively correlated with the amount of torpor used. These findings demonstrate the versatility of torpor throughout the annual cycle and suggest a fundamental change in physiological feedback between adiposity and torpor during migration. Moreover, this study highlights the underappreciated importance of facultative heterothermy in migratory ecology.
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Affiliation(s)
- Erich R Eberts
- Department of Biological Sciences, University of Toronto ScarboroughTorontoCanada,Department of Ecological and Evolutionary Biology, University of TorontoTorontoCanada
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western OntarioLondonCanada
| | - Kenneth C Welch
- Department of Biological Sciences, University of Toronto ScarboroughTorontoCanada,Department of Ecological and Evolutionary Biology, University of TorontoTorontoCanada
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207
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Desforges J, van Beest FM, Marques GM, Pedersen SH, Beumer LT, Chimienti M, Schmidt NM. Quantifying energetic and fitness consequences of seasonal heterothermy in an Arctic ungulate. Ecol Evol 2021; 11:338-351. [PMID: 33437433 PMCID: PMC7790657 DOI: 10.1002/ece3.7049] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/19/2020] [Accepted: 10/29/2020] [Indexed: 11/09/2022] Open
Abstract
Animals have adapted behavioral and physiological strategies to conserve energy during periods of adverse conditions. Heterothermy is one such adaptation used by endotherms. While heterothermy-fluctuations in body temperature and metabolic rate-has been shown in large vertebrates, little is known of the costs and benefits of this strategy, both in terms of energy and in terms of fitness. Hence, our objective was to model the energetics of seasonal heterothermy in the largest Arctic ungulate, the muskox (Ovibos moschatus), using an individual-based energy budget model of metabolic physiology. We found that the empirically based drop in body temperature (winter max ~-0.8°C) overwinter in adult females resulted in substantial fitness benefits in terms of reduced daily energy expenditure and body mass loss. Body mass and energy reserves were 8.98% and 14.46% greater in modeled heterotherms compared to normotherms by end of winter. Based on environmental simulations, we show that seasonal heterothermy can, to some extent, buffer the negative consequences of poor prewinter body condition or reduced winter food accessibility, leading to greater winter survival (+20%-30%) and spring energy reserves (+10%-30%), and thus increased probability of future reproductive success. These results indicate substantial adaptive short-term benefits of seasonal heterothermy at the individual level, with potential implications for long-term population dynamics in highly seasonal environments.
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Affiliation(s)
- Jean‐Pierre Desforges
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
- Department of Natural Resource SciencesMcGill UniversitySte‐Anne‐de‐BellevueQCCanada
| | - Floris M. van Beest
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
| | - Gonçalo M. Marques
- Marine, Environment & Technology Center (MARETEC)Instituto Superior TécnicoUniversidade de LisboaLisboaPortugal
| | - Stine H. Pedersen
- Department of Biological SciencesUniversity of Alaska AnchorageAnchorageAKUSA
- Cooperative Institute for Research in the AtmosphereColorado State UniversityFort CollinsCOUSA
| | | | | | - Niels Martin Schmidt
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
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208
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Senior KL, Ramsauer J, McCarthy MA, Kelly LT. The influence of weather and moon phase on small mammal activity. AUSTRALIAN MAMMALOGY 2021. [DOI: 10.1071/am19056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Small mammals are commonly surveyed using live trapping but the influence of weather conditions on trap success is largely unknown. This information is required to design and implement more effective field surveys and monitoring. We tested the influence of weather and moon phase on capture rates of small mammals in the Murray Mallee region of semi-arid Australia. We used extensive pitfall trapping data collected at 267 sites, totalling 54492 trap-nights. We built regression models to explore the relationship between the capture rates of five species and daily meteorological conditions, and across families of mammals, including dasyurids, burramyids and rodents. A relationship common to several taxa was the positive influence of high winds (>20km h−1) on capture rates. We also identified differences between taxa, with warmer overnight temperatures increasing capture rates of mallee ningaui but decreasing those of Bolam’s mouse. This makes it difficult to determine a single set of ‘optimal’ meteorological conditions for surveying the entire community but points to conditions favourable to individual species and groups. We recommend that surveys undertaken in warmer months encompass a variety of meteorological conditions to increase capture rates and provide a representative sample of the small mammal community present in a landscape.
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209
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Ruuskanen S, Hsu BY, Nord A. Endocrinology of thermoregulation in birds in a changing climate. Mol Cell Endocrinol 2021; 519:111088. [PMID: 33227349 DOI: 10.1016/j.mce.2020.111088] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
The ability to maintain a (relatively) stable body temperature in a wide range of thermal environments by use of endogenous heat production is a unique feature of endotherms such as birds. Endothermy is acquired and regulated via various endocrine and molecular pathways, and ultimately allows wide aerial, aquatic, and terrestrial distribution in variable environments. However, due to our changing climate, birds are faced with potential new challenges for thermoregulation, such as more frequent extreme weather events, lower predictability of climate, and increasing mean temperature. We provide an overview on thermoregulation in birds and its endocrine and molecular mechanisms, pinpointing gaps in current knowledge and recent developments, focusing especially on non-model species to understand the generality of, and variation in, mechanisms. We highlight plasticity of thermoregulation and underlying endocrine regulation, because thorough understanding of plasticity is key to predicting responses to changing environmental conditions. To this end, we discuss how changing climate is likely to affect avian thermoregulation and associated endocrine traits, and how the interplay between these physiological processes may play a role in facilitating or constraining adaptation to a changing climate. We conclude that while the general patterns of endocrine regulation of thermogenesis are quite well understood, at least in poultry, the molecular and endocrine mechanisms that regulate, e.g. mitochondrial function and plasticity of thermoregulation over different time scales (from transgenerational to daily variation), need to be unveiled. Plasticity may ameliorate climate change effects on thermoregulation to some extent, but the increased frequency of extreme weather events, and associated changes in resource availability, may be beyond the scope and/or speed for plastic responses. This could lead to selection for more tolerant phenotypes, if the underlying physiological traits harbour genetic and individual variation for selection to act on - a key question for future research.
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Affiliation(s)
| | - Bin-Yan Hsu
- Department of Biology, University of Turku, Finland
| | - Andreas Nord
- Lund University, Department of Biology, Section for Evolutionary Ecology, Ecology Building, Sölvegatan 37, SE-22362, Lund, Sweden
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210
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Frare C, Williams CT, Drew KL. Thermoregulation in hibernating mammals: The role of the "thyroid hormones system". Mol Cell Endocrinol 2021; 519:111054. [PMID: 33035626 PMCID: PMC8091518 DOI: 10.1016/j.mce.2020.111054] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 07/15/2020] [Accepted: 10/04/2020] [Indexed: 12/19/2022]
Abstract
Hibernation is a unique evolutionary adaptation to conserve energy. During the pre-hibernation (i.e. fall) season, a progressive decline in core body temperature and further decrease in metabolism underlie a seasonal modulation in thermoregulation. The onset of hibernation requires marked changes in thermoregulatory attributes including adjustment in body temperature and tissue specific increases in thermogenic capacity. The hibernation season is characterized by a regulated suppression in thermogenesis allowing the onset of torpor interrupted by periodic activation of thermogenesis to sustain interbout arousals. Thyroid hormones are known to regulate both body temperature and metabolism, and for this reason, the hypothalamic-pituitary-thyroid axis and thyroid hormones have been investigated as modulators of thermogenesis in the phenomenon of hibernation, but the mechanisms remain poorly understood. In this review, we present an overview of what is known about the thermogenic roles of thyroid hormones in hibernating species across seasons and within the hibernating season (torpor-interbout arousal cycle). Overall, the hypothalamic-pituitary-thyroid axis and thyroid hormones play a role in the pre-hibernation season to enhance thermogenic capacity. During hibernation, thermogenesis is attenuated at the level of sympathetic premotor neurons within the raphe pallidus and by deiodinase expression in the hypothalamus. Further, as recent work highlights the direct effect of thyroid hormones within the central nervous system in activating thermogenesis, we speculate how similar mechanisms may occur in hibernating species to modulate thermogenesis across seasons and to sustain interbout arousals. However, further experiments are needed to elucidate the role of thyroid hormones in hibernation, moving towards the understanding that thyroid hormones metabolism, transport and availability within tissues may be the most telling indicator of thyroid status.
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Affiliation(s)
- C Frare
- Department of Chemistry and Biochemistry University of Alaska Fairbanks, Fairbanks, AK, 99775, USA; Institute of Arctic Biology, Center for Transformative Research in Metabolism, University of Alaska Fairbanks 2140 Koyukuk Drive, Fairbanks, AK, 99775, USA
| | - Cory T Williams
- Institute of Arctic Biology, Center for Transformative Research in Metabolism, University of Alaska Fairbanks 2140 Koyukuk Drive, Fairbanks, AK, 99775, USA; Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Kelly L Drew
- Department of Chemistry and Biochemistry University of Alaska Fairbanks, Fairbanks, AK, 99775, USA; Institute of Arctic Biology, Center for Transformative Research in Metabolism, University of Alaska Fairbanks 2140 Koyukuk Drive, Fairbanks, AK, 99775, USA.
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211
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Old JM, Ong OTW, Stannard HJ. Red-tailed phascogales: A review of their biology and importance as model marsupial species. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 335:217-227. [PMID: 33382214 DOI: 10.1002/jez.2438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/09/2022]
Abstract
There are many limitations when using traditional laboratory species. Limits on variation, may result in limited outcomes, at both the species and individual level, due to different individuals/species having diverse physiological processes, or differing molecular and genetic mechanisms. By using a variety of model species, we will be able to develop creative solutions to biological problems and identify differences of which we were not previously aware. The laboratory mouse has been a suitable model species for various mammalian studies, however most are bred specifically for laboratory research with limited variability due to selective breeding. Marsupial models offer unique research opportunities compared to eutherian models. We believe that there should be an expansion in marsupial model species, and the introduction of the red-tailed phascogale (Phascogale calura), a dasyurid marsupial, should be one of them. Phascogales are easily managed in captivity, and there are now multiple studies involving their development, reproduction, nutrition, behavior and immune system, which can serve as a baseline for future studies. The addition of the phascogale as a model species will improve future mammalian studies by introducing variability and offer alternate solutions to biological problems, particularly in the areas of genetics, nutrition, immunology, the neuro-endocrine system, and ageing, due to their semelparous reproductive strategy and hence, subsequent predictive physiology. In this review, we provide information based on existing research on red-tailed phascogales to support their inclusion as a model species.
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Affiliation(s)
- Julie M Old
- School of Science, Hawkesbury Campus, Western Sydney University, Penrith, New South Wales, Australia
| | - Oselyne T W Ong
- Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Hayley J Stannard
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia
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212
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Okrouhlík J, Šumbera R, Gardner B, Schoemann K, Lövy M, Bennett NC. Are southern African solitary mole-rats homeothermic or heterothermic under natural field conditions? J Therm Biol 2020; 95:102810. [PMID: 33454040 DOI: 10.1016/j.jtherbio.2020.102810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 10/22/2022]
Abstract
Abandoning of a stable body temperature (Tb), a phenomenon known as heterothermy, is an adaptation to cope mainly with a lack of food and water, especially in species inhabiting daily or seasonally variable environments. There is increasing evidence that African mammals avoid adverse conditions by heterothermy and eventually by entering torpor. Members of subterranean rodent family, the African mole-rats (Bathyergidae), are suitable candidates to study both phenomena, because of the diversity of their strategies in respect of maintaining stable Tb ranging from homeothermic species to a mammal with the most labile Tb, the naked mole-rat. Currently, there are field data on daily and seasonal Tb in one social species only and such information are lacking for any solitary mole-rat. In our study, we recorded yearly Tb in two solitary bathyergids, the Cape mole-rat Georychus capensis and the Cape dune mole-rat Bathyergus suillus from South Africa using intraperitoneally implanted dataloggers. Since this region is characterised by changing ecological characteristics, we expected either decreases of Tb within 24 h indicating daily torpor and/or longer-term decreases of Tb, which would indicate multiday torpor. Although we found seasonally phase shifted low amplitude daily Tb cycles, we did not find any remarkable and regular daily and/or seasonal Tb deviations, likely showing an absence of torpor in both species. Due to absence of this energy saving mechanism, we may speculate that both species could be vulnerable to ongoing global climatic change.
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Affiliation(s)
- Jan Okrouhlík
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa; Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
| | - Brett Gardner
- Werribee Open Range Zoo, Veterinary Hospital, Zoos Victoria, K Road, Werribee, Victoria, 3029, Australia
| | - Keegan Schoemann
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Nigel Charles Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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213
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Shi Z, Qin M, Huang L, Xu T, Chen Y, Hu Q, Peng S, Peng Z, Qu LN, Chen SG, Tuo QH, Liao DF, Wang XP, Wu RR, Yuan TF, Li YH, Liu XM. Human torpor: translating insights from nature into manned deep space expedition. Biol Rev Camb Philos Soc 2020; 96:642-672. [PMID: 33314677 DOI: 10.1111/brv.12671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.
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Affiliation(s)
- Zhe Shi
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.,Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China
| | - Meng Qin
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lu Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Ying Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qin Hu
- College of Life Sciences and Bio-Engineering, Beijing University of Technology, Beijing, 100024, China
| | - Sha Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Zhuang Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Li-Na Qu
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Shan-Guang Chen
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Qin-Hui Tuo
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Duan-Fang Liao
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Xiao-Ping Wang
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ren-Rong Wu
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China
| | - Ying-Hui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Xin-Min Liu
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Research Center for Pharmacology and Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
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214
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Zhang Z, Reis FMCV, He Y, Park JW, DiVittorio JR, Sivakumar N, van Veen JE, Maesta-Pereira S, Shum M, Nichols I, Massa MG, Anderson S, Paul K, Liesa M, Ajijola OA, Xu Y, Adhikari A, Correa SM. Estrogen-sensitive medial preoptic area neurons coordinate torpor in mice. Nat Commun 2020; 11:6378. [PMID: 33311503 PMCID: PMC7732979 DOI: 10.1038/s41467-020-20050-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/12/2020] [Indexed: 12/15/2022] Open
Abstract
Homeotherms maintain a stable internal body temperature despite changing environments. During energy deficiency, some species can cease to defend their body temperature and enter a hypothermic and hypometabolic state known as torpor. Recent advances have revealed the medial preoptic area (MPA) as a key site for the regulation of torpor in mice. The MPA is estrogen-sensitive and estrogens also have potent effects on both temperature and metabolism. Here, we demonstrate that estrogen-sensitive neurons in the MPA can coordinate hypothermia and hypometabolism in mice. Selectively activating estrogen-sensitive MPA neurons was sufficient to drive a coordinated depression of metabolic rate and body temperature similar to torpor, as measured by body temperature, physical activity, indirect calorimetry, heart rate, and brain activity. Inducing torpor with a prolonged fast revealed larger and more variable calcium transients from estrogen-sensitive MPA neurons during bouts of hypothermia. Finally, whereas selective ablation of estrogen-sensitive MPA neurons demonstrated that these neurons are required for the full expression of fasting-induced torpor in both female and male mice, their effects on thermoregulation and torpor bout initiation exhibit differences across sex. Together, these findings suggest a role for estrogen-sensitive MPA neurons in directing the thermoregulatory and metabolic responses to energy deficiency.
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Affiliation(s)
- Zhi Zhang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Fernando M C V Reis
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Yanlin He
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Jae W Park
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Johnathon R DiVittorio
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Nilla Sivakumar
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - J Edward van Veen
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Shum
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - India Nichols
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Megan G Massa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Shawn Anderson
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ketema Paul
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Marc Liesa
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Avishek Adhikari
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Stephanie M Correa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA.
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA.
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215
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Wilsterman K, Ballinger MA, Williams CM. A unifying, eco‐physiological framework for animal dormancy. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13718] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kathryn Wilsterman
- Biological Sciences University of Montana Missoula MT USA
- Integrative Biology University of California Berkeley CA USA
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216
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Zagkle E, Grosiak M, Bauchinger U, Sadowska ET. Rest-Phase Hypothermia Reveals a Link Between Aging and Oxidative Stress: A Novel Hypothesis. Front Physiol 2020; 11:575060. [PMID: 33362574 PMCID: PMC7756103 DOI: 10.3389/fphys.2020.575060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/17/2020] [Indexed: 01/26/2023] Open
Abstract
In endotherms, growth, reproduction, and survival are highly depended on energy metabolism. Maintenance of constant body temperature can be challenging for endotherms under continuously changing environmental conditions, such as low or high ambient temperatures or limited food. Thus, many birds may drop body temperature below normothermic values during the night, known as rest-phase hypothermia, presumably to decrease energy metabolism. Under the assumption of the positive link between aerobic metabolism and reactive oxygen species, it is reasonable to suggest that low body temperature, a proxy of energy metabolism, will affect oxidative stress of the birds. Aging may considerably affect behavior, performance and physiology in birds and still requires further investigation to understand age-specific changes along the lifespan of the organism. Until today, age-specific rest-phase hypothermic responses and their effect on oxidant-antioxidant status have never been investigated. We exposed 25 zebra finches (Taeniopygia guttata) of three age classes, 12 young birds (1.1–1.3 years old), 8 middle-aged (2.4–2.8 years old), and 5 old birds (4.2–7.5 years old) to day-long food deprivation or provided them normal access to food under thermoneutral conditions. We compared night-time body temperature, measured through implanted data loggers, and quantified plasma oxidative status (uric acid, antioxidant capacity, and d-ROM assay) the following morning. We found age-related differences in night-time body temperature following a day-long food deprivation while all three age groups remained normothermic in the night following a day with access to food. The lowest minimum body temperature (LSM ± SE: 36.6 ± 0.2°C) was observed in old individuals during rest-phase hypothermia. Surprisingly, these old birds also revealed the highest levels of plasma oxidative damage, while young and middle-aged birds maintained higher night-time body temperature and showed lower values of oxidative damage. These results lead us to propose a novel hypothesis on how aging may lead to an accumulation of oxidative damage; the impaired physiological capacity to thermoregulate with advancing age does increase the risk of oxidative stress under challenging conditions. When energy is limited, the risk to encounter oxidative stress is increasing via a compensation to defend normothermic body temperatures.
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Affiliation(s)
- Elisavet Zagkle
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Marta Grosiak
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow, Poland.,Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Edyta T Sadowska
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow, Poland
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217
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Xiong Y, Fan L, Hao Y, Cheng Y, Chang Y, Wang J, Lin H, Song G, Qu Y, Lei F. Physiological and genetic convergence supports hypoxia resistance in high-altitude songbirds. PLoS Genet 2020; 16:e1009270. [PMID: 33370292 PMCID: PMC7793309 DOI: 10.1371/journal.pgen.1009270] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 01/08/2021] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
Skeletal muscle plays a central role in regulating glucose uptake and body metabolism; however, highland hypoxia is a severe challenge to aerobic metabolism in small endotherms. Therefore, understanding the physiological and genetic convergence of muscle hypoxia tolerance has a potential broad range of medical implications. Here we report and experimentally validate a common physiological mechanism across multiple high-altitude songbirds that improvement in insulin sensitivity contributes to glucose homeostasis, low oxygen consumption, and relative activity, and thus increases body weight. By contrast, low-altitude songbirds exhibit muscle loss, glucose intolerance, and increase energy expenditures under hypoxia. This adaptive mechanism is attributable to convergent missense mutations in the BNIP3L gene, and METTL8 gene that activates MEF2C expression in highlanders, which in turn increases hypoxia tolerance. Together, our findings from wild high-altitude songbirds suggest convergent physiological and genetic mechanisms of skeletal muscle in hypoxia resistance, which highlights the potentially medical implications of hypoxia-related metabolic diseases.
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Affiliation(s)
- Ying Xiong
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liqing Fan
- National Forest Ecosystem Observation & Research Station of Nyingchi Tibet, Institute of Plateau Ecology, Tibet Agriculture & Animal Husbandry University, Linzhi City, China
- Key Laboratory of Forest Ecology in Tibet Plateau (Tibet Agriculture & Animal Husbandry University), Ministry of Education, Linzhi City, China
| | - Yan Hao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yalin Cheng
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yongbin Chang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Haiyan Lin
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gang Song
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yanhua Qu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Fumin Lei
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
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218
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Zhang J, Cai R, Liang J, Izaz A, Shu Y, Pan T, Wu X. Molecular mechanism of Chinese alligator (Alligator sinensis) adapting to hibernation. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 336:32-49. [PMID: 33231934 DOI: 10.1002/jez.b.23013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/22/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022]
Abstract
Hibernation is a physiological state for Chinese alligators to cope with cold weather. In mammals, gene expression changes during hibernation and their regulatory mechanisms have been extensively studied, however, these studies in reptiles are still rare. Here, integrated analysis of messenger RNA (mRNA), microRNA (miRNA), and long noncoding RNA (lncRNA) reveals the molecular mechanisms of the hypothalamus, liver, and skeletal muscle in hibernating and active individuals. During hibernation, the number of genes increased in the hypothalamus, liver, and skeletal muscle was 585, 282, and 297, while the number of genes decreased was 215, 561, and 627, respectively, as compared with active individuals. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the differential expressed genes were mainly enriched in DNA damage repair, biological rhythm, energy metabolism, myoprotein degradation, and other related items and pathways. Besides, 4740 miRNAs were identified in three tissues. Through the comprehensive analysis of miRNA and mRNA abundance profiles, 12,291, 6997, and 8232 miRNA-mRNA pairs all showed a negative correlation in the hypothalamus, liver, and skeletal muscle, respectively. Some miRNA target genes were related tobiological rhythm and energy metabolism, suggesting that miRNA may play an important role in the physiological metabolism of the hibernating adaptability of Chinese alligators. Moreover, 402, 230, and 130 differentially expressed lncRNAs were identified in the hypothalamus, liver, and skeletal muscle, respectively. The targeting relationship of four lncRNA-mRNA pairs were predicted, with the main function of target genes involved in the amino acid transportation. These results are helpful to further understand the molecular regulatory basis of the hibernation adaptation in Chinese alligators.
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Affiliation(s)
- Jihui Zhang
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Ruiqing Cai
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Juanjuan Liang
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Ali Izaz
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Yilin Shu
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Tao Pan
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Xiaobing Wu
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China.,College of Life Sciences, Anhui Normal University, Wuhu, China
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219
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Falcón J, Torriglia A, Attia D, Viénot F, Gronfier C, Behar-Cohen F, Martinsons C, Hicks D. Exposure to Artificial Light at Night and the Consequences for Flora, Fauna, and Ecosystems. Front Neurosci 2020; 14:602796. [PMID: 33304237 PMCID: PMC7701298 DOI: 10.3389/fnins.2020.602796] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 10/22/2020] [Indexed: 12/22/2022] Open
Abstract
The present review draws together wide-ranging studies performed over the last decades that catalogue the effects of artificial-light-at-night (ALAN) upon living species and their environment. We provide an overview of the tremendous variety of light-detection strategies which have evolved in living organisms - unicellular, plants and animals, covering chloroplasts (plants), and the plethora of ocular and extra-ocular organs (animals). We describe the visual pigments which permit photo-detection, paying attention to their spectral characteristics, which extend from the ultraviolet into infrared. We discuss how organisms use light information in a way crucial for their development, growth and survival: phototropism, phototaxis, photoperiodism, and synchronization of circadian clocks. These aspects are treated in depth, as their perturbation underlies much of the disruptive effects of ALAN. The review goes into detail on circadian networks in living organisms, since these fundamental features are of critical importance in regulating the interface between environment and body. Especially, hormonal synthesis and secretion are often under circadian and circannual control, hence perturbation of the clock will lead to hormonal imbalance. The review addresses how the ubiquitous introduction of light-emitting diode technology may exacerbate, or in some cases reduce, the generalized ever-increasing light pollution. Numerous examples are given of how widespread exposure to ALAN is perturbing many aspects of plant and animal behaviour and survival: foraging, orientation, migration, seasonal reproduction, colonization and more. We examine the potential problems at the level of individual species and populations and extend the debate to the consequences for ecosystems. We stress, through a few examples, the synergistic harmful effects resulting from the impacts of ALAN combined with other anthropogenic pressures, which often impact the neuroendocrine loops in vertebrates. The article concludes by debating how these anthropogenic changes could be mitigated by more reasonable use of available technology - for example by restricting illumination to more essential areas and hours, directing lighting to avoid wasteful radiation and selecting spectral emissions, to reduce impact on circadian clocks. We end by discussing how society should take into account the potentially major consequences that ALAN has on the natural world and the repercussions for ongoing human health and welfare.
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Affiliation(s)
- Jack Falcón
- Laboratoire Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), MNHN, CNRS FRE 2030, SU, IRD 207, UCN, UA, Paris, France
| | - Alicia Torriglia
- Centre de Recherche des Cordeliers, INSERM U 1138, Ophtalmopole Hôpital Cochin, Assistance Publique - Hôpitaux de Paris, Université de Paris - SU, Paris, France
| | - Dina Attia
- ANSES, French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort, France
| | | | - Claude Gronfier
- Lyon Neuroscience Research Center (CRNL), Waking Team, Inserm UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Lyon, France
| | - Francine Behar-Cohen
- Centre de Recherche des Cordeliers, INSERM U 1138, Ophtalmopole Hôpital Cochin, Assistance Publique - Hôpitaux de Paris, Université de Paris - SU, Paris, France
| | | | - David Hicks
- Inserm, CNRS, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, Strasbourg, France
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220
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Marín G, Ramos-H D, Cafaggi D, Sierra-Durán C, Gallegos A, Romero-Ruiz A, Medellín RA. Challenging hibernation limits of hoary bats: the southernmost record of Lasiurus cinereus hibernating in North America. Mamm Biol 2020. [DOI: 10.1007/s42991-020-00080-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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221
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Aharon-Rotman Y, Körtner G, Wacker CB, Geiser F. Do small precocial birds enter torpor to conserve energy during development? J Exp Biol 2020; 223:jeb231761. [PMID: 32978318 DOI: 10.1242/jeb.231761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/15/2020] [Indexed: 01/24/2023]
Abstract
Precocial birds hatch feathered and mobile, but when they become fully endothermic soon after hatching, their heat loss is high and they may become energy depleted. These chicks could benefit from using energy-conserving torpor, which is characterised by controlled reductions of metabolism and body temperature (Tb). We investigated at what age the precocial king quail Coturnix chinensis can defend a high Tb under a mild thermal challenge and whether they can express torpor soon after achieving endothermy to overcome energetic and thermal challenges. Measurements of surface temperature (Ts) using an infrared thermometer showed that king quail chicks are partially endothermic at 2-10 days, but can defend high Tb at a body mass of ∼13 g. Two chicks expressed shallow nocturnal torpor at 14 and 17 days for 4-5 h with a reduction of metabolism by >40% and another approached the torpor threshold. Although chicks were able to rewarm endogenously from the first torpor bout, metabolism and Ts decreased again by the end of the night, but they rewarmed passively when removed from the chamber. The total metabolic rate increased with body mass. All chicks measured showed a greater reduction of nocturnal metabolism than previously reported in quails. Our data show that shallow torpor can be expressed during the early postnatal phase of quails, when thermoregulatory efficiency is still developing, but heat loss is high. We suggest that torpor may be a common strategy for overcoming challenging conditions during development in small precocial and not only altricial birds.
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Affiliation(s)
- Yaara Aharon-Rotman
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Gerhard Körtner
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Chris B Wacker
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
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222
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González-Bernardo E, Bombieri G, Mar Delgado MD, Penteriani V. The role of spring temperatures in the den exit of female brown bears with cubs in southwestern Europe. URSUS 2020. [DOI: 10.2192/ursus-d-19-00015.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | - Giulia Bombieri
- Research Unit of Biodiversity, UMIB (CSIC/UO/PA), E-33600 Mieres, Spain
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223
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Giroud S, Nord A, Storey KB, Nowack J. Editorial: Coping With Environmental Fluctuations: Ecological and Evolutionary Perspectives. Front Physiol 2020; 11:605186. [PMID: 33192622 PMCID: PMC7645055 DOI: 10.3389/fphys.2020.605186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/16/2020] [Indexed: 11/17/2022] Open
Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Andreas Nord
- Section for Evolutionary Ecology, Department of Biology, Lund University, Lund, Sweden
| | | | - Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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224
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Parallel Accelerated Evolution in Distant Hibernators Reveals Candidate Cis Elements and Genetic Circuits Regulating Mammalian Obesity. Cell Rep 2020; 29:2608-2620.e4. [PMID: 31775032 PMCID: PMC6910134 DOI: 10.1016/j.celrep.2019.10.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/21/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022] Open
Abstract
Obesity is a clinical problem and an important adaptation in many species. Hibernating mammals, for example, become obese, insulin resistant, and hyperinsulinemic to store fat. Here, we combine comparative phylogenomics with large-scale human genome data to uncover candidate cis elements and genetic circuits in different cell types. The Fat Mass and Obesity (FTO) locus, the strongest genetic risk factor for human obesity, is an enriched site for hibernator pARs. Our results uncover noncoding cis elements with putative roles in obesity and hibernation. Obesity is a clinical problem but also an important adaptation in hibernators. By using comparative genomics approaches to analyze the genomes of hibernators from different clades and contrasting the results with human obesity risk loci, Ferris and Gregg found 364 conserved cis elements with putative roles in regulating obesity and hibernation.
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225
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Temperature-Dependent Alternative Splicing of Precursor mRNAs and Its Biological Significance: A Review Focused on Post-Transcriptional Regulation of a Cold Shock Protein Gene in Hibernating Mammals. Int J Mol Sci 2020; 21:ijms21207599. [PMID: 33066638 PMCID: PMC7590145 DOI: 10.3390/ijms21207599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 01/18/2023] Open
Abstract
Multiple mRNA isoforms are often generated during processing such as alternative splicing of precursor mRNAs (pre-mRNA), resulting in a diversity of generated proteins. Alternative splicing is an essential mechanism for the functional complexity of eukaryotes. Temperature, which is involved in all life activities at various levels, is one of regulatory factors for controlling patterns of alternative splicing. Temperature-dependent alternative splicing is associated with various phenotypes such as flowering and circadian clock in plants and sex determination in poikilothermic animals. In some specific situations, temperature-dependent alternative splicing can be evoked even in homothermal animals. For example, the splicing pattern of mRNA for a cold shock protein, cold-inducible RNA-binding protein (CIRP or CIRBP), is changed in response to a marked drop in body temperature during hibernation of hamsters. In this review, we describe the current knowledge about mechanisms and functions of temperature-dependent alternative splicing in plants and animals. Then we discuss the physiological significance of hypothermia-induced alternative splicing of a cold shock protein gene in hibernating and non-hibernating animals.
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226
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Fischl H, McManus D, Oldenkamp R, Schermelleh L, Mellor J, Jagannath A, Furger A. Cold-induced chromatin compaction and nuclear retention of clock mRNAs resets the circadian rhythm. EMBO J 2020; 39:e105604. [PMID: 33034091 PMCID: PMC7667876 DOI: 10.15252/embj.2020105604] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 12/22/2022] Open
Abstract
Cooling patients to sub‐physiological temperatures is an integral part of modern medicine. We show that cold exposure induces temperature‐specific changes to the higher‐order chromatin and gene expression profiles of human cells. These changes are particularly dramatic at 18°C, a temperature synonymous with that experienced by patients undergoing controlled deep hypothermia during surgery. Cells exposed to 18°C exhibit largely nuclear‐restricted transcriptome changes. These include the nuclear accumulation of mRNAs encoding components of the negative limbs of the core circadian clock, most notably REV‐ERBα. This response is accompanied by compaction of higher‐order chromatin and hindrance of mRNPs from engaging nuclear pores. Rewarming reverses chromatin compaction and releases the transcripts into the cytoplasm, triggering a pulse of negative limb gene proteins that reset the circadian clock. We show that cold‐induced upregulation of REV‐ERBα is sufficient to trigger this reset. Our findings uncover principles of the cellular cold response that must be considered for current and future applications involving therapeutic deep hypothermia.
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Affiliation(s)
- Harry Fischl
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - David McManus
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Roel Oldenkamp
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Jane Mellor
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Aarti Jagannath
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - André Furger
- Department of Biochemistry, University of Oxford, Oxford, UK
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227
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Xing X, Liu S, Liu XY, Yang M, Wang DH. Cold exposure increased hypothalamic orexigenic neuropeptides but not food intake in fattening Daurian ground squirrels. ZOOLOGY 2020; 143:125834. [PMID: 32947220 DOI: 10.1016/j.zool.2020.125834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 11/19/2022]
Abstract
Energy balance and thermoregulation in many fat-storing seasonal hibernators show a circannual rhythm. To understand the physiological mechanisms of the seasonal pre-hibernation fattening related to the regulation of energy expenditure and thermogenesis, we cold-exposed fattening Daurian ground squirrels (Spermophilus dauricus) in late summer for 3 weeks. We predicted that cold-exposed squirrels would increase food intake rather than express torpor to accommodate both fattening and thermoregulatory fuel allocation. Food intake and body mass were quantified. After 3 weeks, body compositions, serum leptin concentration, expression of hypothalamic neuropeptides related to regulation of energy balance and uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) were measured. There was no change in body mass after 3-weeks of cold exposure. Hypothalamic orexigenic neuropeptides and UCP1 levels in BAT were up-regulated after cold exposure. Food intake, serum leptin concentration and the expression of leptin signal suppressors, suppressor of cytokine signaling 3 and protein tyrosine phosphatase 1B, in hypothalamus showed no differences compared with controls. The core body temperature was unaffected by cold exposure. Our data suggest that cold exposure affected fattening mainly because of the increased heat loss, whereas energy balance and thermoregulation are under control of a strong circannual rhythm in the Daurian ground squirrels.
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Affiliation(s)
- Xin Xing
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Sciences, Peking University, Beijing, 100871, China
| | - Shuai Liu
- College of Life Science, Shenyang Normal University, Shenyang, 110034, China
| | - Xin-Yu Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Science, Shenyang Normal University, Shenyang, 110034, China
| | - Ming Yang
- College of Life Science, Shenyang Normal University, Shenyang, 110034, China.
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, China.
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228
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Heldstab SA, van Schaik CP, Müller DWH, Rensch E, Lackey LB, Zerbe P, Hatt JM, Clauss M, Matsuda I. Reproductive seasonality in primates: patterns, concepts and unsolved questions. Biol Rev Camb Philos Soc 2020; 96:66-88. [PMID: 32964610 DOI: 10.1111/brv.12646] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 08/08/2020] [Accepted: 08/17/2020] [Indexed: 01/23/2023]
Abstract
Primates, like other mammals, exhibit an annual reproductive pattern that ranges from strictly seasonal breeding to giving birth in all months of the year, but factors mediating this variation are not fully understood. We applied both a categorical description and quantitative measures of the birth peak breadth based on daily observations in zoos to characterise reproductive seasonality in 141 primate species with an average of 941 birth events per species. Absolute day length at the beginning of the mating season in seasonally reproducing species was not correlated between populations from natural habitats and zoos. The mid-point of latitudinal range was a major factor associated with reproductive seasonality, indicating a correlation with photoperiod. Gestation length, annual mean temperature, natural diet and Malagasy origin were other important factors associated with reproductive seasonality. Birth seasons were shorter with increasing latitude of geographical origin, corresponding to the decreasing length of the favourable season. Species with longer gestation periods were less seasonal than species with shorter ones, possibly because shorter gestation periods more easily facilitate the synchronisation of reproductive activity with annual cycles. Habitat conditions with higher mean annual temperature were also linked to less-seasonal reproduction, independently of the latitude effect. Species with a high percentage of leaves in their natural diet were generally non-seasonal, potentially because the availability of mature leaves is comparatively independent of seasons. Malagasy primates were more seasonal in their births than species from other regions. This might be due to the low resting metabolism of Malagasy primates, the comparatively high degree of temporal predictability of Malagasy ecosystems, or historical constraints peculiar to Malagasy primates. Latitudinal range showed a weaker but also significant association with reproductive seasonality. Amongst species with seasonal reproduction in their natural habitats, smaller primate species were more likely than larger species to shift to non-seasonal breeding in captivity. The percentage of species that changed their breeding pattern in zoos was higher in primates (30%) than in previous studies on Carnivora and Ruminantia (13 and 10%, respectively), reflecting a higher concentration of primate species in the tropics. When comparing only species that showed seasonal reproduction in natural habitats at absolute latitudes ≤11.75°, primates did not differ significantly from these two other taxa in the proportion of species that changed to a less-seasonal pattern in zoos. However, in this latitude range, natural populations of primates and Carnivora had a significantly higher proportion of seasonally reproducing species than Ruminantia, suggesting that in spite of their generally more flexible diets, both primates and Carnivora are more exposed to resource fluctuation than ruminants.
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Affiliation(s)
- Sandra A Heldstab
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland.,Department of Anthropology, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Carel P van Schaik
- Department of Anthropology, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Dennis W H Müller
- Zoological Garden Halle (Saale), Fasanenstrasse 5a, 06114, Halle (Saale), Germany
| | - Eberhard Rensch
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Laurie Bingaman Lackey
- World Association of Zoos and Aquariums (WAZA), Carrer de Roger de Llúria, 2, 2-2, Barcelona, Spain
| | - Philipp Zerbe
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Jean-Michel Hatt
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Ikki Matsuda
- Chubu University Academy of Emerging Sciences, 1200, Matsumoto-cho, Kasugai-shi, Aichi, 487-8501, Japan.,Wildlife Research Center of Kyoto University, 2-24 Tanaka-Sekiden-cho, Sakyo, Kyoto, 606-8203, Japan.,Japan Monkey Centre, Inuyama, Aichi, 484-0081, Japan.,Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
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229
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Mohr SM, Bagriantsev SN, Gracheva EO. Cellular, Molecular, and Physiological Adaptations of Hibernation: The Solution to Environmental Challenges. Annu Rev Cell Dev Biol 2020; 36:315-338. [PMID: 32897760 DOI: 10.1146/annurev-cellbio-012820-095945] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Thriving in times of resource scarcity requires an incredible flexibility of behavioral, physiological, cellular, and molecular functions that must change within a relatively short time. Hibernation is a collection of physiological strategies that allows animals to inhabit inhospitable environments, where they experience extreme thermal challenges and scarcity of food and water. Many different kinds of animals employ hibernation, and there is a spectrum of hibernation phenotypes. Here, we focus on obligatory mammalian hibernators to identify the unique challenges they face and the adaptations that allow hibernators to overcome them. This includes the cellular and molecular strategies used to combat low environmental and body temperatures and lack of food and water. We discuss metabolic, neuronal, and hormonal cues that regulate hibernation and how they are thought to be coordinated by internal clocks. Last, we touch on questions that are left to be addressed in the field of hibernation research. Studies from the last century and more recent work reveal that hibernation is not simply a passive reduction in body temperature and vital parameters but rather an active process seasonally regulated at the molecular, cellular, and organismal levels.
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Affiliation(s)
- Sarah M Mohr
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
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230
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Boratyński JS, Iwińska K, Szafrańska PA, Chibowski P, Bogdanowicz W. Continuous growth through winter correlates with increased resting metabolic rate but does not affect daily energy budgets due to torpor use. Curr Zool 2020; 67:131-145. [PMID: 33854531 PMCID: PMC8026158 DOI: 10.1093/cz/zoaa047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 08/26/2020] [Indexed: 11/20/2022] Open
Abstract
Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter. By contrast, heterothermic ones that are considered generalists in thermoregulation can lower energy expenditure by entering torpor. It is well known that different species vary the use of their strategies to cope with harsh winters in temperate zones; however, little is still known about the intraspecific variation within populations and the associated external and internal factors. We hypothesized that yellow-necked mice Apodemus flavicollis decrease their resting metabolic rate (RMR) from autumn to winter, and then increase it during spring. However, since the alternative for seasonal reduction of RMR could be the development of heterothermy, we also considered the use of this strategy. We measured body mass (mb), RMR, and body temperature (Tb) of mice during 2 consecutive years. In the 1st year, mice decreased whole animal RMR in winter, but did not do so in the 2nd year. All mice entered torpor during the 2nd winter, whereas only a few did so during the first one. Mice showed a continuous increase of mb, which was steepest during the 2nd year. The relationship between RMR and mb varied among seasons and years most likely due to different mouse development stages. The mb gain at the individual level was correlated positively with RMR and heterothermy. This indicates that high metabolism in winter supports the growth of smaller animals, which use torpor as a compensatory mechanism. Isotope composition of mice hair suggests that in the 1st year they fed mainly on seeds, while in the 2nd, they likely consumed significant amounts of less digestible herbs. The study suggests that the use of specialist or generalist thermoregulatory strategies can differ with environmental variation and associated differences in developmental processes.
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Affiliation(s)
- Jan S Boratyński
- Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland
| | - Karolina Iwińska
- Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland.,Faculty of Biology, University of Białystok, Białystok, Poland
| | | | - Piotr Chibowski
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warszawa, Poland
| | - Wiesław Bogdanowicz
- Museum and Institute of Zoology, Polish Academy of Sciences, Warszawa, Poland
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231
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Green SR, Al-Attar R, McKechnie AE, Naidoo S, Storey KB. Role of Akt signaling pathway regulation in the speckled mousebird (Colius striatus) during torpor displays tissue specific responses. Cell Signal 2020; 75:109763. [PMID: 32871209 DOI: 10.1016/j.cellsig.2020.109763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/06/2020] [Accepted: 08/25/2020] [Indexed: 10/23/2022]
Abstract
Pronounced heterothermic responses are relatively rare among birds. Along with taxa such as hummingbirds and caprimulgids, the order Coliiformes (mousebirds) is known to possess the physiological capacity for torpor. During torpor, body temperature is greatly reduced and a bird becomes unresponsive to external stimuli until ambient temperatures return to more favorable conditions. Under such conditions, these birds are forced to rely only on their internal fuel storage for energy and show great reduction in metabolic rates by decreasing energy-expensive processes. This study investigated the role of the key insulin-Akt signaling kinase pathway involved in regulating energy metabolism and protein translation in the liver, kidney, heart, skeletal muscle, and brain of the speckled mousebird (Colius striatus). The degree of phosphorylation of well-conserved target residues with important regulatory function was examined in both the euthermic control and torpid birds. The results demonstrated marked differences in responses between the tissues with decreases in RPS6 S235/236 phosphorylation in the kidney (0.52 fold of euthermic) and muscle (0.29 fold of euthermic) as well as decreases in GS3K3β S9 in muscle (0.60 fold of euthermic) and GSK3α S21 (0.71 fold of euthermic) phosphorylation in kidney during torpor, suggesting a downregulation of this pathway. Interestingly, the liver demonstrated an increase in RPS6 S235/236 (2.89 fold increase) and P70S6K T412 (1.44 fold increase) phosphorylation in the torpor group suggesting that protein translation is maintained in this tissue. This study demonstrates that avian torpor is a complex phenomenon and alterations in this signaling pathway follow a tissue specific pattern.
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Affiliation(s)
- Stuart R Green
- Institute of Biochemistry & Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa K1S 5B6, Ontario, Canada
| | - Rasha Al-Attar
- Institute of Biochemistry & Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa K1S 5B6, Ontario, Canada
| | - Andrew E McKechnie
- South African Research Chair in Conservation Physiology, National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa; DST-NRF Centre of Excellence, FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Samantha Naidoo
- South African Research Chair in Conservation Physiology, National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa; DST-NRF Centre of Excellence, FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Kenneth B Storey
- Institute of Biochemistry & Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa K1S 5B6, Ontario, Canada.
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232
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Czenze ZJ, Dunbar M. Body mass affects short‐term heterothermy in Neotropical bats. Biotropica 2020. [DOI: 10.1111/btp.12807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zenon J. Czenze
- South African Research Chair in Conservation Physiology South African National Biodiversity Institute Pretoria South Africa
- Mammal Research Institute Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | - Miranda Dunbar
- Department of Biology Southern Connecticut State University New Haven CT USA
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233
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Martínková N, Baird SJE, Káňa V, Zima J. Bat population recoveries give insight into clustering strategies during hibernation. Front Zool 2020; 17:26. [PMID: 32884575 PMCID: PMC7465407 DOI: 10.1186/s12983-020-00370-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/13/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Behaviour during hibernation contributes to energy conservation in winter. Hibernating bats select roosts with respect to physiological and environmental stressors, available local microclimate and species-specific requirements. RESULTS We found that, in the period between 1977 and 2018, hibernating Myotis myotis and Rhinolophus hipposideros bats showed exponential population growth. The growth rates, corrected for local winter seasonal severity and winter duration, were equal to 10 and 13%, respectively. While R. hipposideros only utilised the thermally stable and, at survey time, warmer corridors in the hibernaculum, an increasing proportion of M. myotis roosted in the thermally stable corridors as their abundance increased. About 14% of all hibernating M. myotis displayed solitary roosting, irrespective of other covariates. Those bats that clustered together formed progressively larger clusters with increasing abundance, particularly in cold corridors. We found no statistically significant relationship for clustering behaviour or cluster size with winter severity or winter duration. CONCLUSIONS Abundance of hibernating bats is increasing in Central Europe. As the number of M. myotis bats increases, thermally unstable corridors become saturated with large clusters and the animals begin to roost deeper underground.
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Affiliation(s)
- Natália Martínková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
- RECETOX, Masaryk University, Kamenice 753/5, Brno, 62500 Czechia
| | - Stuart J. E. Baird
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
| | | | - Jan Zima
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
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234
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Wolf BO, McKechnie AE, Schmitt CJ, Czenze ZJ, Johnson AB, Witt CC. Extreme and variable torpor among high-elevation Andean hummingbird species. Biol Lett 2020; 16:20200428. [PMID: 32898456 PMCID: PMC7532710 DOI: 10.1098/rsbl.2020.0428] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/14/2020] [Indexed: 11/12/2022] Open
Abstract
Torpor is thought to be particularly important for small endotherms occupying cold environments and with limited fat reserves to fuel metabolism, yet among birds deep torpor is both rare and variable in extent. We investigated torpor in hummingbirds at approximately 3800 m.a.s.l. in the tropical Andes by monitoring body temperature (Tb) in 26 individuals of six species held captive overnight and experiencing natural air temperature (Ta) patterns. All species used pronounced torpor, with one Metallura phoebe reaching a minimum Tb of 3.26°C, the lowest yet reported for any bird or non-hibernating mammal. The extent and duration of torpor varied among species, with overnight body mass (Mb) loss negatively correlated with both minimum Tb and bout duration. We found a significant phylogenetic signal for minimum Tb and overnight Mb loss, consistent with evolutionarily conserved thermoregulatory traits. Our findings suggest deep torpor is routine for high Andean hummingbirds, but evolved species differences affect its depth.
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Affiliation(s)
- Blair O. Wolf
- Department of Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
| | - Andrew E. McKechnie
- South African Research Chair in Conservation Physiology, South African National Biodiversity Institute, PO Box 754, Pretoria 0001, South Africa
- DST-NRF Centre of Excellence at the FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, Private Bag X20, Pretoria 0028, South Africa
| | - C. Jonathan Schmitt
- Department of Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA
- Museum of Southwestern Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
| | - Zenon J. Czenze
- South African Research Chair in Conservation Physiology, South African National Biodiversity Institute, PO Box 754, Pretoria 0001, South Africa
- DST-NRF Centre of Excellence at the FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, Private Bag X20, Pretoria 0028, South Africa
| | - Andrew B. Johnson
- Department of Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
- Museum of Southwestern Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
| | - Christopher C. Witt
- Department of Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
- Museum of Southwestern Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 87131-0001, USA
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235
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Menzies AK, Studd EK, Majchrzak YN, Peers MJL, Boutin S, Dantzer B, Lane JE, McAdam AG, Humphries MM. Body temperature, heart rate, and activity patterns of two boreal homeotherms in winter: Homeostasis, allostasis, and ecological coexistence. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13640] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Allyson K. Menzies
- Department of Natural Resource Sciences McGill University Ste‐Anne‐de‐Bellevue QC Canada
| | - Emily K. Studd
- Department of Natural Resource Sciences McGill University Ste‐Anne‐de‐Bellevue QC Canada
- Department of Biological Sciences University of Alberta Edmonton AB Canada
| | | | | | - Stan Boutin
- Department of Biological Sciences University of Alberta Edmonton AB Canada
| | - Ben Dantzer
- Department of Psychology University of Michigan Ann Arbor MI USA
- Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor MI USA
| | - Jeffrey E. Lane
- Department of Biology University of Saskatchewan Saskatoon SK Canada
| | - Andrew G. McAdam
- Department of Ecology and Evolutionary Biology University of Colorado Boulder CO USA
| | - Murray M. Humphries
- Department of Natural Resource Sciences McGill University Ste‐Anne‐de‐Bellevue QC Canada
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236
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Fietz J, Langer F, Schlund W. They like it cold, but only in winter: Climate‐mediated effects on a hibernator. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13630] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Joanna Fietz
- Department of Zoology Faculty of Natural Sciences Institute of Biology University of Hohenheim Stuttgart Germany
| | - Franz Langer
- Department of Zoology Faculty of Natural Sciences Institute of Biology University of Hohenheim Stuttgart Germany
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237
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South KE, Haynes K, Jackson AC. Hibernation Patterns of the European Hedgehog, Erinaceus europaeus, at a Cornish Rescue Centre. Animals (Basel) 2020; 10:ani10081418. [PMID: 32823861 PMCID: PMC7459883 DOI: 10.3390/ani10081418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Populations of the European hedgehog, Erinaceus europaeus, are declining in the UK. This small mammal is frequently admitted to rescue centres in the UK to be treated for a variety of illnesses or injuries. With many spending the winter in captivity, clear guidelines about how to look after hedgehogs during their hibernation would be very useful. We studied 35 hedgehogs over two winters to learn about their sleeping behaviour and how they change weight. We measured the total length of hibernation and the periods during hibernation when hedgehogs are more active (called spontaneous arousals). There were three main results. (1) The longer the hibernation, the more weight was lost. (2) Previous studies show that arousal is energetically expensive. Despite this, weight-loss was more related to the amount of time spent sleeping than to the number of times the hedgehog woke up, perhaps because they could easily feed each time they woke up. (3) Larger hedgehogs lost proportionally less weight per day, perhaps because they woke up and fed more often than did smaller hedgehogs. Behaviour by hibernating hedgehogs in captivity differs from that in the wild. Patterns revealed in this study are used to make some recommendations for guidelines that can be adapted for individual hedgehogs according to their size and behaviour during hibernation. Abstract The European hedgehog, Erinaceus europaeus, is frequently admitted to rescue centres in the UK. With many overwintering in captivity, there is cause to investigate hibernation patterns in order to inform and improve husbandry and monitoring protocols. Thirty-five hedgehogs were studied over two winters. Weight change during hibernation for the first winter was used to test for effects of disturbance on different aspects of hibernation, including total duration, frequency and duration of spontaneous arousals. There was no significant difference between the two winters for any of the four aspects studied. Significant positive correlations demonstrated that weight-loss increased with the duration of the hibernation period and with percent of nights spent asleep, but not with the number of arousal events. Thus, weight-loss appears more strongly associated with the proportion of time spent asleep than with the number of arousal events. This was surprising given the assumed energetic expense of repeated arousal and was potentially due to availability of food during arousals. In contrast with previous studies, larger hedgehogs lost less weight per day than did smaller hedgehogs. They also woke up more often (i.e., had more opportunities to feed), which may explain the unexpected pattern of weight-loss. Hibernatory behaviour in captivity differs from that in the wild, likely because of non-natural conditions in hutches and the immediate availability of food. This study provides a basis for further research into the monitoring and husbandry of hedgehogs such that it can be adapted for each individual according to pre-hibernation weight and behaviour during hibernation.
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Affiliation(s)
- Kathryn E. South
- Prickles and Paws Hedgehog Rescue, Cubert, Newquay, Cornwall TR8 5HD, UK
- Centre for Applied Zoology, Cornwall College Newquay, Newquay, Cornwall TR7 2LZ, UK; (K.H.); (A.C.J.)
- Correspondence:
| | - Kelly Haynes
- Centre for Applied Zoology, Cornwall College Newquay, Newquay, Cornwall TR7 2LZ, UK; (K.H.); (A.C.J.)
| | - Angus C. Jackson
- Centre for Applied Zoology, Cornwall College Newquay, Newquay, Cornwall TR7 2LZ, UK; (K.H.); (A.C.J.)
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Landes J, Pavard S, Henry PY, Terrien J. Flexibility Is Costly: Hidden Physiological Damage From Seasonal Phenotypic Transitions in Heterothermic Species. Front Physiol 2020; 11:985. [PMID: 32903301 PMCID: PMC7434983 DOI: 10.3389/fphys.2020.00985] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022] Open
Abstract
Heterothermy allows organisms to cope with fluctuating environmental conditions. The use of regulated hypometabolism allows seasonal heterothermic species to cope with annual resource shortages and thus to maximize survival during the unfavorable season. This comes with deep physiological remodeling at each seasonal transition to allow the organism to adjust to the changing environment. In the wild, this adaptation is highly beneficial and largely overcomes potential costs. However, researchers recently proposed that it might also generate both ecological and physiological costs for the organism. Here, we propose new perspectives to be considered when analyzing adaptation to seasonality, in particular considering these costs. We propose a list of putative costs, including DNA damage, inflammatory response to fat load, brain and cognitive defects, digestive malfunction and immunodeficiency, that should receive more attention in future research on physiological seasonality. These costs may only be marginal at each transition event but accumulate over time and therefore emerge with age. In this context, studies in captivity, where we have access to aging individuals with limited extrinsic mortality (e.g., predation), could be highly valuable to experimentally assess the costs of physiological flexibility. Finally, we offer new perspectives, which should be included in demographic models, on how the adaptive value of physiological flexibility could be altered in the future in the context of global warming.
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Affiliation(s)
- Julie Landes
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France.,Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université de Paris, Paris, France
| | - Samuel Pavard
- Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université de Paris, Paris, France
| | - Pierre-Yves Henry
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Jérémy Terrien
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France
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Geiser F, Willis CKR, Brigham RM. No evidence for hibernation in rockwrens. J Exp Biol 2020; 223:jeb229518. [PMID: 32788270 DOI: 10.1242/jeb.229518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/04/2020] [Indexed: 11/20/2022]
Affiliation(s)
- Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology CO2, University of New England, Armidale, NSW 2351, Australia
| | - Craig K R Willis
- Department of Biology and Centre for Forest Interdisciplinary Research, University of Winnipeg, Winnipeg, Canada, MB R3B 2E9
| | - R Mark Brigham
- Department of Biology, University of Regina, Regina, Canada, SK S4S 0A2
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Patterns of Feeding by Householders Affect Activity of Hedgehogs ( Erinaceus europaeus) during the Hibernation Period. Animals (Basel) 2020; 10:ani10081344. [PMID: 32759762 PMCID: PMC7460126 DOI: 10.3390/ani10081344] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 11/22/2022] Open
Abstract
Simple Summary Urban areas are thought to represent a stronghold habitat for the West European hedgehog population in the UK. However, little is known about hibernation patterns in residential areas and if overwinter activity is influenced by any ”urban-associated” factors. We monitored hedgehog activity in gardens during the winter hibernation period of 2017–2018 using weekly presence/absence surveys. Hedgehogs were more likely to be present in gardens where householders had provided food in previous seasons or where food was supplied more regularly in a given season. Such relationships could have positive or negative effects on the survival or condition of hedgehogs across the hibernation period. Consequently, further research is needed to identify the effects of supplementary feeding on hibernation biology to help inform conservation guidelines for householders. Abstract West European hedgehogs (Erinaceus europaeus) are likely to encounter unusual ecological features in urban habitats, such as anthropogenic food sources and artificial refugia. Quantifying how these affect hedgehog behaviour is vital for informing conservation guidelines for householders. We monitored hedgehog presence/absence in gardens in the town of Reading, UK, over the winter of 2017–2018 using a volunteer-based footprint tunnel survey, and collected data on garden characteristics, supplementary feeding (SF) habits, and local environmental conditions. Over a 20-week survey period, hedgehog presence was lowest between January and March. Occupancy analysis indicated that SF significantly affected hedgehog presence/absence before, during, and after hibernation. The number of nesting opportunities available in gardens, average temperatures, and daylength were also supported as important factors at different stages. In particular, our results suggest that SF could act to increase levels of activity during the winter when hedgehogs should be hibernating. Stimulating increased activity at this sensitive time could push hedgehogs into a net energy deficit or, conversely, help some individuals survive which might not otherwise do so. Therefore, further research is necessary to determine whether patterns of feeding by householders have a positive or negative effect on hedgehog populations during the hibernation period.
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241
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Comparison of natural and pharmacological hypothermia in animals: Determination of activation energy of metabolism. J Therm Biol 2020; 92:102658. [DOI: 10.1016/j.jtherbio.2020.102658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023]
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Shiratsuru S, Friebe A, Swenson JE, Zedrosser A. Room without a view-Den excavation in relation to body size in brown bears. Ecol Evol 2020; 10:8044-8054. [PMID: 32788960 PMCID: PMC7417226 DOI: 10.1002/ece3.6371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 11/22/2022] Open
Abstract
Hibernation is an adaptive strategy to survive harsh winter conditions and food shortage. The use of well-insulated winter dens helps animals minimize energy loss during hibernation. Brown bears (Ursus arctos) commonly use excavated dens for hibernation. Physical attributes of excavated dens are expected to impact the bear's heat retention and energy conservation. The objective of this study was to examine the determinants of cavity size of excavated dens and the impact of physical attributes of excavated dens on energy conservation in hibernating bears, hypothesizing that bears excavate dens in a way to minimize heat loss and optimize energy conservation during hibernation. We predicted that den cavity size would be determined by the bear's body size and that older bears would excavate better-fitting cavities to minimize heat loss, due to their previous experience. We further predicted that physical attributes of excavated dens would affect the bears' posthibernation body condition. Our results revealed that bears excavated a den cavity in relation to their body size, regardless of sex, and that older bears tended to excavate better-fitting den cavities compared to young bears, as we expected. Older bears excavated better-fitting den cavities, suggesting a potentially experience-based shift with age in den-excavation behavior and an optimum cavity size relative to a bear's body size. Our key finding is that insulation of excavated dens provided by wall/rood thickness and bedding materials had a significant positive effect on bears' posthibernation body condition. We believe that our study provides new insight into how not only the quality of denning habitat, but also the quality of dens may affect hibernating animals, by presenting a potential adaptive aspect of den preparation (age effect on efficiency in den excavation) and effect of den attributes on the posthibernation body condition of brown bears.
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Affiliation(s)
| | - Andrea Friebe
- Scandinavian Brown Bear Research ProjectOrsaSweden
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Jon E. Swenson
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
| | - Andreas Zedrosser
- Department of Natural Sciences and Environmental HealthUniversity of South‐Eastern NorwayTelemarkNorway
- Department of Integrative BiologyInstitute of Wildlife Biology and Game ManagementUniversity of Natural Resources and Life SciencesViennaAustria
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243
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Ng R, Su CY. Neuroscience: Sensing Absolute Cold. Curr Biol 2020; 30:R809-R811. [PMID: 32693074 DOI: 10.1016/j.cub.2020.05.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To overwinter, animals must detect constant cold temperatures before adapting their behavior accordingly. A new study in Drosophila describes a circuit mechanism - from sensory neurons to higher brain centers - that encodes and relays persistent, absolute cold stimuli to modulate sleep.
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Affiliation(s)
- Renny Ng
- Neurobiology Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Chih-Ying Su
- Neurobiology Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA.
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244
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Constant T, Giroud S, Viblanc VA, Tissier ML, Bergeron P, Dobson FS, Habold C. Integrating Mortality Risk and the Adaptiveness of Hibernation. Front Physiol 2020; 11:706. [PMID: 32754044 PMCID: PMC7366871 DOI: 10.3389/fphys.2020.00706] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 05/28/2020] [Indexed: 11/16/2022] Open
Abstract
Low mortality rate is often associated with slow life history, and so far, has mainly been assessed through examinations of specific adaptations and lifestyles that limit mortality risk. However, the organization of activity time budgets also needs to be considered, since some activities and the time afforded for performing them may expose animals to higher mortality risks such as increased predation and/or increased metabolic stress. We examined the extent of activity time budgets contribution to explaining variation in life history traits in mammals. We specifically focused on hibernating species because of their marked seasonal cycle of activity/inactivity associated with very different mortality risks. Hibernation is considered a seasonal adaptation to prolonged periods of food shortage and cold. This inactivity period may also reduce both extrinsic and intrinsic mortality risks, by decreasing exposure to predators and drastically reducing metabolic rate. In turn, reduction in mortality may explain why hibernators have slower life history traits than non-hibernators of the same size. Using phylogenetically controlled models, we tested the hypothesis that longevity was positively correlated with the hibernation season duration (the time spent between immergence and emergence from the hibernaculum or den) across 82 different mammalian species. We found that longevity increased significantly with hibernation season duration, an effect that was particularly strong in small hibernators (<1.5 kg) especially for bats. These results confirm that hibernation not only allows mammals to survive periods of energy scarcity, but further suggest that activity time budgets may be selected to reduce mortality risks according to life history pace.
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Affiliation(s)
- Théo Constant
- UMR 7178, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert CURIEN, Université de Strasbourg, Strasbourg, France
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Vincent A. Viblanc
- UMR 7178, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert CURIEN, Université de Strasbourg, Strasbourg, France
| | - Mathilde L. Tissier
- Department of Biological Sciences, Bishop’s University, Sherbrooke, QC, Canada
| | - Patrick Bergeron
- Department of Biological Sciences, Bishop’s University, Sherbrooke, QC, Canada
| | - F. Stephen Dobson
- UMR 7178, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert CURIEN, Université de Strasbourg, Strasbourg, France
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| | - Caroline Habold
- UMR 7178, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert CURIEN, Université de Strasbourg, Strasbourg, France
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245
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González-Bernardo E, Russo LF, Valderrábano E, Fernández Á, Penteriani V. Denning in brown bears. Ecol Evol 2020; 10:6844-6862. [PMID: 32724555 PMCID: PMC7381752 DOI: 10.1002/ece3.6372] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/16/2020] [Accepted: 04/22/2020] [Indexed: 12/12/2022] Open
Abstract
Hibernation represents an adaptation for coping with unfavorable environmental conditions. For brown bears Ursus arctos, hibernation is a critical period as pronounced temporal reductions in several physiological functions occur.Here, we review the three main aspects of brown bear denning: (1) den chronology, (2) den characteristics, and (3) hibernation physiology in order to identify (a) proximate and ultimate factors of hibernation as well as (b) research gaps and conservation priorities.Den chronology, which varies by sex and reproductive status, depends on environmental factors, such as snow, temperature, food availability, and den altitude. Significant variation in hibernation across latitudes occurs for both den entry and exit.The choice of a den and its surroundings may affect individual fitness, for example, loss of offspring and excessive energy consumption. Den selection is the result of broad- and fine-scale habitat selection, mainly linked to den insulation, remoteness, and availability of food in the surroundings of the den location.Hibernation is a metabolic challenge for the brown bears, in which a series of physiological adaptations in tissues and organs enable survival under nutritional deprivation, maintain high levels of lipids, preserve muscle, and bone and prevent cardiovascular pathologies such as atherosclerosis. It is important to understand: (a) proximate and ultimate factors in denning behavior and the difference between actual drivers of hibernation (i.e., factors to which bears directly respond) and their correlates; (b) how changes in climatic factors might affect the ability of bears to face global climate change and the human-mediated changes in food availability; (c) hyperphagia (period in which brown bears accumulate fat reserves), predenning and denning periods, including for those populations in which bears do not hibernate every year; and (d) how to approach the study of bear denning merging insights from different perspectives, that is, physiology, ecology, and behavior.
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Affiliation(s)
- Enrique González-Bernardo
- Research Unit of Biodiversity (UMIB, CSIC-UO-PA) Mieres Spain
- Pyrenean Institute of Ecology (IPE-CSIC) Zaragoza Spain
| | - Luca Francesco Russo
- Research Unit of Biodiversity (UMIB, CSIC-UO-PA) Mieres Spain
- Department of Biosciences and the Territory Università degli Studi del Molise Pesche Italy
| | - Esther Valderrábano
- COPAR Research Group Faculty of Veterinary University of Santiago de Compostela Lugo Spain
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246
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Jefimow M, Przybylska-Piech AS, Wojciechowski MS. Predictive and reactive changes in antioxidant defence system in a heterothermic rodent. J Comp Physiol B 2020; 190:479-492. [PMID: 32435827 PMCID: PMC7311498 DOI: 10.1007/s00360-020-01280-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 04/03/2020] [Accepted: 04/27/2020] [Indexed: 11/26/2022]
Abstract
Living in a seasonal environment requires periodic changes in animal physiology, morphology and behaviour. Winter phenotype of small mammals living in Temperate and Boreal Zones may differ considerably from summer one in multiple traits that enhance energy conservation or diminish energy loss. However, there is a considerable variation in the development of winter phenotype among individuals in a population and some, representing the non-responding phenotype (non-responders), are insensitive to shortening days and maintain summer phenotype throughout a year. Differences in energy management associated with the development of different winter phenotypes should be accompanied by changes in antioxidant defence capacity, leading to effective protection against oxidative stress resulting from increased heat production in winter. To test it, we analysed correlation of winter phenotypes of Siberian hamsters (Phodopus sungorus) with facultative non-shivering thermogenesis capacity (NST) and oxidative status. We found that in both phenotypes acclimation to winter-like conditions increased NST capacity and improved antioxidant defence resulting in lower oxidative stress (OS) than in summer, and females had always lower OS than males. Although NST capacity did not correlate with the intensity of OS, shortly after NST induction responders had lower OS than non-responders suggesting more effective mechanisms protecting from detrimental effects of reactive oxygen metabolites generated during rewarming from torpor. We suggest that seasonal increase in antioxidant defence is programmed endogenously to predictively prevent oxidative stress in winter. At the same time reactive upregulation of antioxidant defence protects against reactive oxygen species generated during NST itself. It suggests that evolution of winter phenotype with potentially harmful characteristics was counterbalanced by the development of protective mechanisms allowing for the maintenance of phenotypic adjustments to seasonally changing environment.
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Affiliation(s)
- Małgorzata Jefimow
- Department of Animal Physiology and Neurobiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland.
| | - Anna S Przybylska-Piech
- Department of Vertebrate Zoology and Ecology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland
| | - Michał S Wojciechowski
- Department of Vertebrate Zoology and Ecology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland
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247
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Dausmann KH, Levesque DL, Wein J, Nowack J. Ambient Temperature Cycles Affect Daily Torpor and Hibernation Patterns in Malagasy Tenrecs. Front Physiol 2020; 11:522. [PMID: 32547412 PMCID: PMC7270353 DOI: 10.3389/fphys.2020.00522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/28/2020] [Indexed: 11/30/2022] Open
Abstract
Hibernation and daily torpor (heterothermy) allow endotherms to cope with demanding environmental conditions. The depth and duration of torpor bouts vary considerably between tropical and temperate climates, and tropical hibernators manage to cope with a wider spectrum of ambient temperature (Ta) regimes during heterothermy. As cycles in Ta can have profound effects on activity and torpor patterns as well as energy expenditure, we examined how these characteristics are affected by daily fluctuating versus constant Ta in a tropical hibernator, the lesser hedgehog tenrec (Echinops telfairi). Throughout the study, regardless of season, the tenrecs became torpid every day. In summer, E. telfairi used daily fluctuations in Ta to passively rewarm from daily torpor, which led to synchrony in the activity phases and torpor bouts between individuals and generally decreased energy expenditure. In contrast, animals housed at constant Ta showed considerable variation in timing and they had to invest more energy through endogenous heat production. During the hibernation season (winter) E. telfairi hibernated for several months in constant, as well as in fluctuating Ta and, as in summer, under fluctuating Ta arousals were much more uniform and showed less variation in timing compared to constant temperature regimes. The timing of torpor is not only important for its effective use, but synchronization of activity patterns could also be essential for social interactions, and successful foraging bouts. Our results highlight that Ta cycles can be an effective zeitgeber for activity and thermoregulatory rhythms throughout the year and that consideration should be given to the choice of temperature regime when studying heterothermy under laboratory conditions.
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Affiliation(s)
- Kathrin H Dausmann
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Danielle L Levesque
- School of Biology and Ecology, University of Maine, Orono, ME, United States
| | - Jens Wein
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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248
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Northeast RC, Vyazovskiy VV, Bechtold DA. Eat, sleep, repeat: the role of the circadian system in balancing sleep-wake control with metabolic need. CURRENT OPINION IN PHYSIOLOGY 2020; 15:183-191. [PMID: 32617440 PMCID: PMC7323618 DOI: 10.1016/j.cophys.2020.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Feeding and sleep are behaviours fundamental to survival, and as such are subject to powerful homeostatic control. Of course, these are mutually exclusive behaviours, and therefore require coordinated temporal organisation to ensure that both energy demands and sleep need are met. Under optimal conditions, foraging/feeding and sleep can be simply partitioned to appropriate phases of the circadian cycle so that they are in suitable alignment with the external environment. However, under conditions of negative energy balance, increased foraging activity must be balanced against sleep requirements and energy conservation. In mammals and many other species, neural circuits that regulate sleep and energy balance are intimately and reciprocally linked. Here, we examine this circuitry, discuss how homeostatic regulation and temporal patterning of sleep are modulated by altered food availability, and describe the role of circadian system in adaptation to metabolic stress.
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Affiliation(s)
- Rebecca C Northeast
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
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249
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Bernard RF, Reichard JD, Coleman JTH, Blackwood JC, Verant ML, Segers JL, Lorch JM, White J, Moore MS, Russell AL, Katz RA, Lindner DL, Toomey RS, Turner GG, Frick WF, Vonhof MJ, Willis CKR, Grant EHC. Identifying research needs to inform white‐nose syndrome management decisions. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.220] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Riley F. Bernard
- Department of Ecosystem Science and ManagementPennsylvania State University University Park Pennsylvania USA
- United States Geological Survey Patuxent Wildlife Research CenterSO Conte Anadromous Fish Research Laboratory Turners Falls Massachusetts USA
| | | | | | - Julie C. Blackwood
- Department of Mathematics and StatisticsWilliams College Williamstown Massachusetts USA
| | - Michelle L. Verant
- Biological Resource DivisionWildlife Health Branch Fort Collins Colorado USA
| | - Jordi L. Segers
- Canadian Wildlife Health Cooperative Charlottetown Prince Edward Island Canada
| | - Jeffery M. Lorch
- United States Geological Survey National Wildlife Health Center Madison Wisconsin USA
| | - John White
- Bureau of Natural Heritage ConservationWisconsin Department of Natural Resources Madison Wisconsin USA
| | - Marianne S. Moore
- College of Integrative Science and ArtsArizona State University Mesa Arizona USA
| | - Amy L. Russell
- Department of BiologyGrand Valley State University Allendale Michigan USA
| | - Rachel A. Katz
- United States Fish and Wildlife Service Hadley Massachusetts USA
| | - Daniel L. Lindner
- United States Forest ServiceNorthern Research Station Madison Wisconsin USA
| | | | | | - Winifred F. Frick
- Department of Ecology and Evolutionary BiologyUniversity of California Santa Cruz California USA
- Bat Conservation International Austin Texas USA
| | - Maarten J. Vonhof
- Department of Biological SciencesWestern Michigan University Kalamazoo Michigan USA
- Institute of the Environment and SustainabilityWestern Michigan University Kalamazoo Michigan USA
| | | | - Evan H. C. Grant
- United States Geological Survey Patuxent Wildlife Research CenterSO Conte Anadromous Fish Research Laboratory Turners Falls Massachusetts USA
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250
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Regalado-Reyes M, Benavides-Piccione R, Fernaud-Espinosa I, DeFelipe J, León-Espinosa G. Effect of Phosphorylated Tau on Cortical Pyramidal Neuron Morphology during Hibernation. Cereb Cortex Commun 2020; 1:tgaa018. [PMID: 34296096 PMCID: PMC8152943 DOI: 10.1093/texcom/tgaa018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/02/2020] [Accepted: 05/03/2020] [Indexed: 12/17/2022] Open
Abstract
The dendritic spines of pyramidal cells are the main postsynaptic target of excitatory glutamatergic synapses. Morphological alterations have been described in hippocampal dendritic spines during hibernation-a state of inactivity and metabolic depression that occurs via a transient neuronal tau hyperphosphorylation. Here, we have used the hibernating Syrian hamster to investigate the effect of hyperphosphorylated tau regarding neocortical neuronal structure. In particular, we examined layer Va pyramidal neurons. Our results indicate that hibernation does not promote significant changes in dendritic spine density. However, tau hyperphosphorylated neurons show a decrease in complexity, an increase in the tortuosity of the apical dendrites, and an increase in the diameter of the basal dendrites. Tau protein hyperphosphorylation and aggregation have been associated with loss or alterations of dendritic spines in neurodegenerative diseases, such as Alzheimer's disease (AD). Our results may shed light on the correlation between tau hyperphosphorylation and the neuropathological processes in AD. Moreover, we observed changes in the length and area of the apical and basal dendritic spines during hibernation regardless of tau hyperphosphorylation. The morphological changes observed here also suggest region specificity, opening up debate about a possible relationship with the differential brain activity registered in these regions in previous studies.
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Affiliation(s)
- Mamen Regalado-Reyes
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28002, Spain
| | - Ruth Benavides-Piccione
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28002, Spain
| | - Isabel Fernaud-Espinosa
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28002, Spain
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28002, Spain
| | - Gonzalo León-Espinosa
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28002, Spain
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