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Hervas LS, do Amaral-Silva L, Sartori MR, Guadalupe-Silva A, Gargaglioni LH, Lerchner J, Oliveira MT, Bícego KC. Mitochondrial function in skeletal muscle contributes to reproductive endothermy in tegu lizards (Salvator merianae). Acta Physiol (Oxf) 2024; 240:e14162. [PMID: 38741523 DOI: 10.1111/apha.14162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 04/17/2024] [Accepted: 04/28/2024] [Indexed: 05/16/2024]
Abstract
AIM In cyclic climate variations, including seasonal changes, many animals regulate their energy demands to overcome critical transitory moments, restricting their high-demand activities to phases of resource abundance, enabling rapid growth and reproduction. Tegu lizards (Salvator merianae) are ectotherms with a robust annual cycle, being active during summer, hibernating during winter, and presenting a remarkable endothermy during reproduction in spring. Here, we evaluated whether changes in mitochondrial respiratory physiology in skeletal muscle could serve as a mechanism for the increased thermogenesis observed during the tegu's reproductive endothermy. METHODS We performed high-resolution respirometry and calorimetry in permeabilized red and white muscle fibers, sampled during summer (activity) and spring (high activity and reproduction), in association with citrate synthase measurements. RESULTS During spring, the muscle fibers exhibited increased oxidative phosphorylation. They also enhanced uncoupled respiration and heat production via adenine nucleotide translocase (ANT), but not via uncoupling proteins (UCP). Citrate synthase activity was higher during the spring, suggesting greater mitochondrial density compared to the summer. These findings were consistent across both sexes and muscle types (red and white). CONCLUSION The current results highlight potential cellular thermogenic mechanisms in an ectothermic reptile that contribute to transient endothermy. Our study indicates that the unique feature of transitioning to endothermy through nonshivering thermogenesis during the reproductive phase may be facilitated by higher mitochondrial density, function, and uncoupling within the skeletal muscle. This knowledge contributes significant elements to the broader picture of models for the evolution of endothermy, particularly in relation to the enhancement of aerobic capacity.
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Affiliation(s)
- Livia Saccani Hervas
- Department of Animal Morphology and Physiology, São Paulo State University, Jaboticabal, Brazil
| | - Lara do Amaral-Silva
- Department of Biology, Wake Forest University, Winston Salem, North Carolina, USA
| | - Marina Rincon Sartori
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Ane Guadalupe-Silva
- Department of Animal Morphology and Physiology, São Paulo State University, Jaboticabal, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, São Paulo State University, Jaboticabal, Brazil
| | - Johannes Lerchner
- Institute of Physical Chemistry, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Kênia Cardoso Bícego
- Department of Animal Morphology and Physiology, São Paulo State University, Jaboticabal, Brazil
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2
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Trenholme HN. Sedation and Anesthesia in Exotic Animal Critical Care. Vet Clin North Am Exot Anim Pract 2023:S1094-9194(23)00021-X. [PMID: 37349182 DOI: 10.1016/j.cvex.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Sedation and anesthesia of exotic animals in inherently challenging, but often facilitates the best care for patients. Critical illness or injury adds on another layer of complexity to their management for obtaining diagnostics and providing treatments. This article serves to review some of the more recent literature of sedation and anesthesia within exotics practice, bringing to light some nuances and considerations for when those patients are critically ill or injured.
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Affiliation(s)
- H Nicole Trenholme
- Department of Veterinary Clinical Medicine, University of Illinois College of Veterinary Medicine, 1008 West Hazelwood Drive, LAC 251, Urbana, IL 61802, USA.
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3
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Wang Y, Riedstra B, Groothuis T. Embryonic heart rate is affected by yolk androgens and egg laying sequence, and correlates with embryonic tissue growth: A study in rock pigeons. Gen Comp Endocrinol 2023; 333:114213. [PMID: 36642229 DOI: 10.1016/j.ygcen.2023.114213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/09/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Maternal androgen exposure can have crucial effects on offspring development. Bird eggs are frequently used for studying these effects and virtually all research in this field has focused on post-hatching offspring traits. Yet, much of the yolk, in which the maternal hormones are deposited, is consumed during the embryonic phase. Here, we studied the effects of yolk androgens during this prenatal period. As there is evidence that androgens stimulate post-hatching traits such as increased growth, we measured heart rate throughout incubation as a proxy for prenatal metabolism. Rock pigeons (Columba livia) typically lay 2-egg clutches with yolk androgen levels in second-laid eggs being consistently higher than in first-laid eggs. We investigated whether embryonic heart rate was higher in second- than first-laid eggs. Additionally, we increased yolk androgen levels (testosterone and androstenedione) with the mean difference between those in first- and second-laid eggs, to investigate whether the effects of androgens are egg sequence dependent. As expected, embryonic heart rate predicted body embryo organ- and body mass, and body dimensions, with body mass being significantly higher in second- than first-laid eggs. Androgen treated first-laid eggs increased heart rate to that of second-laid control eggs only temporally, yet it had an overall positive effect on embryo body dimensions but not on tissue mass. Our findings indicate that embryos from different egg laying sequence differed in heart rate and prenatal development outcomes but this can only partially be explained by their difference in maternal androgen levels.
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Affiliation(s)
- Yuqi Wang
- University of Groningen, Groningen Institute for Evolutionary Life Sciences, the Netherlands.
| | - Bernd Riedstra
- University of Groningen, Groningen Institute for Evolutionary Life Sciences, the Netherlands
| | - Ton Groothuis
- University of Groningen, Groningen Institute for Evolutionary Life Sciences, the Netherlands
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Rial RV, Akaârir M, Canellas F, Barceló P, Rubiño JA, Martín-Reina A, Gamundí A, Nicolau MC. Mammalian NREM and REM sleep: Why, when and how. Neurosci Biobehav Rev 2023; 146:105041. [PMID: 36646258 DOI: 10.1016/j.neubiorev.2023.105041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/14/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
This report proposes that fish use the spinal-rhombencephalic regions of their brain to support their activities while awake. Instead, the brainstem-diencephalic regions support the wakefulness in amphibians and reptiles. Lastly, mammals developed the telencephalic cortex to attain the highest degree of wakefulness, the cortical wakefulness. However, a paralyzed form of spinal-rhombencephalic wakefulness remains in mammals in the form of REMS, whose phasic signs are highly efficient in promoting maternal care to mammalian litter. Therefore, the phasic REMS is highly adaptive. However, their importance is low for singletons, in which it is a neutral trait, devoid of adaptive value for adults, and is mal-adaptive for marine mammals. Therefore, they lost it. The spinal-rhombencephalic and cortical wakeful states disregard the homeostasis: animals only attend their most immediate needs: foraging defense and reproduction. However, these activities generate allostatic loads that must be recovered during NREMS, that is a paralyzed form of the amphibian-reptilian subcortical wakefulness. Regarding the regulation of tonic REMS, it depends on a hypothalamic switch. Instead, the phasic REMS depends on an independent proportional pontine control.
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Affiliation(s)
- Rubén V Rial
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
| | - Mourad Akaârir
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
| | - Francesca Canellas
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut; Hospital Son Espases, 07120, Palma de Mallorca (España).
| | - Pere Barceló
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
| | - José A Rubiño
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut; Hospital Son Espases, 07120, Palma de Mallorca (España).
| | - Aida Martín-Reina
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
| | - Antoni Gamundí
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
| | - M Cristina Nicolau
- Laboratori de Fisiologia del son i els ritmes biologics. Universitat de les Illes Balears, Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca (España); IDISBA. Institut d'Investigació Sanitaria de les Illes Balears; IUNICS Institut Universitari d'Investigació en Ciències de la Salut.
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Wang Z, Nie Y, Yu S, Chen L, Zhang L, Zhu W, Zhou Z, Diao J. Consolidation of temperature-dependent toxicity and thermoregulatory behavior into risk assessments of insecticides under thermal scenarios: A prospective study on Eremias argus. ENVIRONMENT INTERNATIONAL 2023; 172:107742. [PMID: 36669286 DOI: 10.1016/j.envint.2023.107742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/10/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
In this study, the temperature-dependent chemical toxicity of three insecticides and the resulting thermoregulatory (TR) behavior of the lizard Eremias argus have been consolidated into the current risk assessment framework. According to acute dermal toxicity assays, an increase of ambient temperature from 15 °C to 35 °C decreased the acute dermal toxicity of beta-cyfluthrin (BC) but increased the toxicity of chlorpyrifos (CPF). The toxicity of avermectin (AVM) did not show significant temperature-dependent responses. Based on thermal preference trials, lizards changed their body temperature via TR behavior to adaptively reduce toxicity under sub-lethal doses, which can be understood as a "self-rescue" behavior attenuating lethal effects. However, the risk quotient indicated that the effectiveness of this "self-rescue" behavior is limited. Metabolomics analysis showed that six different metabolites (i.e., creatine, glutamate, succinate, N-acetylaspartate, acetylcholine, and lactate) contributed to TR behavior changes. Biochemical assays and insecticide residue results demonstrated that the temperature-dependent toxicity of BC, CPF, and AVM affected lizards in the three aspects of biotransformation, oxidative stress, and neurometabolic interference. This work clarifies the ecotoxicological impacts of representative insecticides on reptiles from toxicological understanding to risk relevance. This knowledge may improve ecological predictions of agrochemical applications in the context of global climate change.
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Affiliation(s)
- Zikang Wang
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Yufan Nie
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Simin Yu
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Li Chen
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Luyao Zhang
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Wentao Zhu
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Zhiqiang Zhou
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Jinling Diao
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China.
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Tavares D, da Silva Matos SLB, Duran LM, Castro SA, Taylor EW, Filogonio R, Fernandes MN, Leite CA. Baroreflex responses of decerebrate rattlesnakes (Crotalus durissus) are comparable to awake animals. Comp Biochem Physiol A Mol Integr Physiol 2022; 273:111286. [DOI: 10.1016/j.cbpa.2022.111286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 11/30/2022]
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Rial RV, Canellas F, Akaârir M, Rubiño JA, Barceló P, Martín A, Gamundí A, Nicolau MC. The Birth of the Mammalian Sleep. BIOLOGY 2022; 11:biology11050734. [PMID: 35625462 PMCID: PMC9138988 DOI: 10.3390/biology11050734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/05/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Mammals evolved from reptiles as a consequence of an evolutionary bottleneck. Some diurnal reptiles extended their activity, first to twilight and then to the entire dark time. This forced the change of the visual system. Pursuing maximal sensitivity, they abandoned the filters protecting the eyes against the dangerous diurnal light, which, in turn, forced immobility in lightproof burrows during light time. This was the birth of the mammalian sleep. Then, the Cretacic-Paleogene extinction of dinosaurs leaved free the diurnal niche and allowed the expansion of a few early mammals to diurnal life and the high variability of sleep traits. On the other hand, we propose that the idling rest is a state showing homeostatic regulation. Therefore, the difference between behavioral rest and wakeful idling is rather low: both show quiescence, raised sensory thresholds, reversibility, specific sleeping-resting sites and body positions, it is a pleasing state, and both are dependent of circadian and homeostatic regulation. Indeed, the most important difference is the unconsciousness of sleep and the consciousness of wakeful idling. Thus, we propose that sleep is a mere upgrade of the wakeful rest, and both may have the same function: guaranteeing rest during a part of the daily cycle. Abstract Mammals evolved from small-sized reptiles that developed endothermic metabolism. This allowed filling the nocturnal niche. They traded-off visual acuity for sensitivity but became defenseless against the dangerous daylight. To avoid such danger, they rested with closed eyes in lightproof burrows during light-time. This was the birth of the mammalian sleep, the main finding of this report. Improved audition and olfaction counterweighed the visual impairments and facilitated the cortical development. This process is called “The Nocturnal Evolutionary Bottleneck”. Pre-mammals were nocturnal until the Cretacic-Paleogene extinction of dinosaurs. Some early mammals returned to diurnal activity, and this allowed the high variability in sleeping patterns observed today. The traits of Waking Idleness are almost identical to those of behavioral sleep, including homeostatic regulation. This is another important finding of this report. In summary, behavioral sleep seems to be an upgrade of Waking Idleness Indeed, the trait that never fails to show is quiescence. We conclude that the main function of sleep consists in guaranteeing it during a part of the daily cycle.
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Affiliation(s)
- Rubén V. Rial
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- Correspondence: ; Tel.: +34-971-173-147; Fax: +34-971-173-184
| | - Francesca Canellas
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Mourad Akaârir
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - José A. Rubiño
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Pere Barceló
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Aida Martín
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Antoni Gamundí
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - M. Cristina Nicolau
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
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Mohanty NP, Wagener C, Herrel A, Thaker M. The ecology of sleep in non-avian reptiles. Biol Rev Camb Philos Soc 2021; 97:505-526. [PMID: 34708504 DOI: 10.1111/brv.12808] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 10/10/2021] [Accepted: 10/18/2021] [Indexed: 01/10/2023]
Abstract
Sleep is ubiquitous in the animal kingdom and yet displays considerable variation in its extent and form in the wild. Ecological factors, such as predation, competition, and microclimate, therefore are likely to play a strong role in shaping characteristics of sleep. Despite the potential for ecological factors to influence various aspects of sleep, the ecological context of sleep in non-avian reptiles remains understudied and without systematic direction. In this review, we examine multiple aspects of reptilian sleep, including (i) habitat selection (sleep sites and their spatio-temporal distribution), (ii) individual-level traits, such as behaviour (sleep postures), morphology (limb morphometrics and body colour), and physiology (sleep architecture), as well as (iii) inter-individual interactions (intra- and inter-specific). Throughout, we discuss the evidence of predation, competition, and thermoregulation in influencing sleep traits and the possible evolutionary consequences of these sleep traits for reptile sociality, morphological specialisation, and habitat partitioning. We also review the ways in which sleep ecology interacts with urbanisation, biological invasions, and climate change. Overall, we not only provide a systematic evaluation of the conceptual and taxonomic biases in the existing literature on reptilian sleep, but also use this opportunity to organise the various ecological hypotheses for sleep characteristics. By highlighting the gaps and providing a prospectus of research directions, our review sets the stage for understanding sleep ecology in the natural world.
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Affiliation(s)
- Nitya P Mohanty
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560 012, India
| | - Carla Wagener
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, Western Cape, 7600, South Africa
| | - Anthony Herrel
- Département Adaptations du Vivant, MECADEV UMR7179 CNRS/MNHN, Paris, France
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560 012, India
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9
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Domínguez-Godoy MA, Hudson R, Pérez-Mendoza HA, Ancona S, Díaz de la Vega-Pérez AH. Living on the edge: Lower thermal quality but greater survival probability at a high altitude mountain for the mesquite lizard (Sceloporus grammicus). J Therm Biol 2020; 94:102757. [PMID: 33292998 DOI: 10.1016/j.jtherbio.2020.102757] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 08/27/2020] [Accepted: 10/04/2020] [Indexed: 11/15/2022]
Abstract
A 20-month recapture analysis of 1001 individually marked mesquite lizards (Sceloporus grammicus) suggests that variation in thermal quality across three altitudes influences survival probability. Each additional unit of deviation from the temperature selected by these lizards in previous laboratory experiments (i.e. decreased thermal quality) meant an increase of roughly 1.01% in survival probability. Survival probabilities ranged from 0.80 to 0.90 at the lowest elevation site (2600 m), from 0.76 to 0.87 at the middle elevation site (3100 m) and from 0.90 to 0.94 at the highest elevation site (4150 m). These results suggest that in poor thermal quality environments mesquite lizards may employ thermoregulatory strategies (behavioral, physiological and/or morphological) to decrease their metabolic expenditure and their exposure to predators, maximizing survival. These findings highlight the relevance of thermal quality of the habitat in determining survival probability of ectotherms.
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Affiliation(s)
- Miguel A Domínguez-Godoy
- Doctorado en Ciencias Biológicas, Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carretera Tlaxcala-Puebla km 1.5 C.P., 90062, Tlaxcala, Mexico
| | - Robyn Hudson
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.P., 04510, Mexico City, Mexico
| | - Hibrahim A Pérez-Mendoza
- Laboratorio de Ecología Evolutiva de Anfibios y Reptiles, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de Los Barrios Número 1, Los Reyes Iztacala, Tlalnepantla, Estado de México, 54090, Mexico
| | - Sergio Ancona
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, C.P., 04510, Mexico City, Mexico
| | - Aníbal H Díaz de la Vega-Pérez
- Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carretera Tlaxcala-Puebla km 1.5, C.P., 90062, Tlaxcala, Mexico.
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10
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Filogonio R, Orsolini KF, Oda GM, Malte H, Leite CAC. Baroreflex gain and time of pressure decay at different body temperatures in the tegu lizard, Salvator merianae. PLoS One 2020; 15:e0242346. [PMID: 33227002 PMCID: PMC7682859 DOI: 10.1371/journal.pone.0242346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/01/2020] [Indexed: 12/20/2022] Open
Abstract
Ectotherms may experience large body temperature (Tb) variations. Higher Tb have been reported to increase baroreflex sensitivity in ectotherm tetrapods. At lower Tb, pulse interval (PI) increases and diastolic pressure decays for longer, possibly resulting in lower end-diastolic pressures and mean arterial pressures (Pm). Additionally, compensatory baroreflex-related heart rate modulation (i.e. the cardiac branch of the baroreflex response) is delayed due to increased PI. Thus, low Tb is potentially detrimental, leading to cardiovascular malfunctioning. This raises the question on how Pm is regulated in such an adverse condition. We investigated the baroreflex compensations that enables tegu lizards, Salvator merianae, to maintain blood pressure homeostasis in a wide Tb range. Lizards had their femoral artery cannulated and pressure signals recorded at 15°C, 25°C and 35°C. We used the sequence method to analyse the heart rate baroreflex-related corrections to spontaneous pressure fluctuations at each temperature. Vascular adjustments (i.e. the peripheral branch) were assessed by calculating the time constant for arterial pressure decay (τ)—resultant from the action of both vascular resistance and compliance—by fitting the diastolic pressure descent to the two-element Windkessel equation. We observed that at lower Tb, lizards increased baroreflex gain at the operating point (Gop) and τ, indicating that the diastolic pressure decays at a slower rate. Gop normalized to Pm and PI, as well as the ratio τ/PI, did not change, indicating that both baroreflex gain and rate of pressure decay are adjusted according to PI lengthening. Consequently, pressure parameters and the oscillatory power fraction (an index of wasted cardiac energy) were unaltered by Tb, indicating that both Gop and τ modulation are crucial for cardiovascular homeostasis.
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Affiliation(s)
- Renato Filogonio
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, São Paulo, Brazil
- * E-mail:
| | - Karina F. Orsolini
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - Gustavo M. Oda
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - Hans Malte
- Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus C, Denmark
| | - Cléo A. C. Leite
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, São Paulo, Brazil
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11
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Duran LM, Taylor EW, Sanches PVW, Cruz AL, Tavares D, Sartori MR, Abe AS, Leite CAC. Heart rate variability in the tegu lizard, Salvator merianae, its neuroanatomical basis and role in the assessment of recovery from experimental manipulation. Comp Biochem Physiol A Mol Integr Physiol 2019; 240:110607. [PMID: 31707060 DOI: 10.1016/j.cbpa.2019.110607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 10/25/2022]
Abstract
Using long-term, remote recordings of heart rate (fH) on fully recovered, undisturbed lizards, we identified several components of heart rate variability (HRV) associated with respiratory sinus arrhythmia (RSA): 1.) A peak in the spectral representation of HRV at the frequency range of ventilation. 2.) These cardiorespiratory interactions were shown to be dependent on the parasympathetic arm of the autonomic nervous system. 3.) Vagal preganglionic neurons are located in discrete groups located in the dorsal motor nucleus of the vagus and also, in a ventro-lateral group, homologous to the nucleus ambiguus of mammals. 4.) Myelinated nerve fibers in the cardiac vagus enabling rapid communication between the central nervous system and the heart. Furthermore, the study of the progressive recovery of fH in tegu following anesthesia and instrumentation revealed that 'resting' levels of mean fH and reestablishment of HRV occurred over different time courses. Accordingly, we suggest that, when an experiment is designed to study a physiological variable reliant on autonomic modulation at its normal, resting level, then postsurgical reestablishment of HRV should be considered as the index of full recovery, rather than mean fH.
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Affiliation(s)
- Livia M Duran
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos 13.565-905, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - Edwin W Taylor
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos 13.565-905, SP, Brazil
| | - Pollyana V W Sanches
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos 13.565-905, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - André L Cruz
- Institute of Biology, Federal University of Bahia (UFBA), Salvador 40.140-310, BA, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - Driele Tavares
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos 13.565-905, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - Marina R Sartori
- Department of Zoology, São Paulo State University (UNESP), Rio Claro 13.506-900, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - Augusto S Abe
- Department of Zoology, São Paulo State University (UNESP), Rio Claro 13.506-900, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil
| | - Cleo A C Leite
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos 13.565-905, SP, Brazil; National Institute of Science and Technology in Comparative Physiology, INCT, FISC, FAPESP/CNPq, Rio Claro 13.506-900, SP, Brazil.
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12
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Strahl-Heldreth DE, Clark-Price SC, Keating SCJ, Escalante GC, Graham LF, Chinnadurai SK, Schaeffer DJ. Effect of intracoelomic administration of alfaxalone on the righting reflex and tactile stimulus response of common garter snakes (Thamnophis sirtalis). Am J Vet Res 2019; 80:144-151. [DOI: 10.2460/ajvr.80.2.144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Sheldon EL, Griffith SC. Embryonic heart rate predicts prenatal development rate, but is not related to post‐natal growth rate or activity level in the zebra finch (
Taeniopygia guttata
). Ethology 2018. [DOI: 10.1111/eth.12817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth L. Sheldon
- Department of Biological Sciences Macquarie University Sydney New South Wales Australia
| | - Simon C. Griffith
- Department of Biological Sciences Macquarie University Sydney New South Wales Australia
- School of Biological, Earth and Environmental Sciences University of New South Wales Sydney New South Wales Australia
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14
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Libourel PA, Barrillot B, Arthaud S, Massot B, Morel AL, Beuf O, Herrel A, Luppi PH. Partial homologies between sleep states in lizards, mammals, and birds suggest a complex evolution of sleep states in amniotes. PLoS Biol 2018; 16:e2005982. [PMID: 30307933 PMCID: PMC6181266 DOI: 10.1371/journal.pbio.2005982] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 08/30/2018] [Indexed: 12/19/2022] Open
Abstract
It is crucial to determine whether rapid eye movement (REM) sleep and slow-wave sleep (SWS) (or non-REM sleep), identified in most mammals and birds, also exist in lizards, as they share a common ancestor with these groups. Recently, a study in the bearded dragon (P. vitticeps) reported states analogous to REM and SWS alternating in a surprisingly regular 80-s period, suggesting a common origin of the two sleep states across amniotes. We first confirmed these results in the bearded dragon with deep brain recordings and electro-oculogram (EOG) recordings. Then, to confirm a common origin and more finely characterize sleep in lizards, we developed a multiparametric approach in the tegu lizard, a species never recorded to date. We recorded EOG, electromyogram (EMG), heart rate, and local field potentials (LFPs) and included data on arousal thresholds, sleep deprivation, and pharmacological treatments with fluoxetine, a serotonin reuptake blocker that suppresses REM sleep in mammals. As in the bearded dragon, we demonstrate the existence of two sleep states in tegu lizards. However, no clear periodicity is apparent. The first sleep state (S1 sleep) showed high-amplitude isolated sharp waves, and the second sleep state (S2 sleep) displayed 15-Hz oscillations, isolated ocular movements, and a decrease in heart rate variability and muscle tone compared to S1. Fluoxetine treatment induced a significant decrease in S2 quantities and in the number of sharp waves in S1. Because S2 sleep is characterized by the presence of ocular movements and is inhibited by a serotonin reuptake inhibitor, as is REM sleep in birds and mammals, it might be analogous to this state. However, S2 displays a type of oscillation never previously reported and does not display a desynchronized electroencephalogram (EEG) as is observed in the bearded dragons, mammals, and birds. This suggests that the phenotype of sleep states and possibly their role can differ even between closely related species. Finally, our results suggest a common origin of two sleep states in amniotes. Yet, they also highlight a diversity of sleep phenotypes across lizards, demonstrating that the evolution of sleep states is more complex than previously thought. Until recently, the general understanding about sleep was that only mammals and birds show two sleep states: slow-wave sleep and rapid eye movement (REM) sleep. Consequently, it was thought that these two states appeared independently in these warm-blooded animals. However, a recent paper reported the presence of these two states in the bearded dragon lizard (Pogona vitticeps), suggesting that these two states arose with the common ancestor of mammals, birds, and reptiles. We confirmed the presence of two sleep states in the bearded dragon and compared its sleep with that of another lizard, the Argentine tegu (Salvator merianae). Our results show that both lizard species have two sleep states with similarities to the two sleep states observed in mammals and birds. Additionally, our study of behavioral and physiological parameters as well as the brain activity associated with sleep in these lizards allowed us to also show important differences between these two species of lizards and between lizards, birds, and mammals. Our findings indicate that sleep in lizards is more complex than previously thought and raise further questions about the nature, function, and evolution of these two sleep states.
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Affiliation(s)
- Paul-Antoine Libourel
- Neuroscience Research Center of Lyon, SLEEP Team, UMR 5292 CNRS/U1028 INSERM, Université Claude Bernard Lyon 1, Lyon, France
- * E-mail:
| | - Baptiste Barrillot
- Neuroscience Research Center of Lyon, SLEEP Team, UMR 5292 CNRS/U1028 INSERM, Université Claude Bernard Lyon 1, Lyon, France
| | - Sébastien Arthaud
- Neuroscience Research Center of Lyon, SLEEP Team, UMR 5292 CNRS/U1028 INSERM, Université Claude Bernard Lyon 1, Lyon, France
| | - Bertrand Massot
- Nanotechnologies Institute of Lyon, UMR5270 CNRS, INSA Lyon, Université Claude Bernard Lyon 1, France
| | - Anne-Laure Morel
- Neuroscience Research Center of Lyon, SLEEP Team, UMR 5292 CNRS/U1028 INSERM, Université Claude Bernard Lyon 1, Lyon, France
| | - Olivier Beuf
- Health Image Processing and Acquisition Research Center of Lyon, UMR 5220 CNRS/U1206 INSERM, INSA Lyon, Université Claude Bernard Lyon 1, LYON, France
| | - Anthony Herrel
- MECADEV, UMR7179 CNRS, National Museum of Natural History, Paris, France
- University of Antwerp, Department of Biology, Antwerpen, Belgium
- Ghent University, Evolutionary Morphology of Vertebrates, Ghent, Belgium
| | - Pierre-Hervé Luppi
- Neuroscience Research Center of Lyon, SLEEP Team, UMR 5292 CNRS/U1028 INSERM, Université Claude Bernard Lyon 1, Lyon, France
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15
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Bars-Closel M, Camacho A, Kohlsdorf T. Shifts in space and time: ecological transitions affect the evolution of resting metabolic rates in microteiid lizards. ACTA ACUST UNITED AC 2018; 221:jeb.175661. [PMID: 29880636 DOI: 10.1242/jeb.175661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/31/2018] [Indexed: 10/14/2022]
Abstract
Ecological diversification often encompasses exposure to new thermal regimes given by the use of specific spatial (microhabitat) and temporal (activity periods) niches. Empirical evidence provides links between temperature and physiology (e.g. rates of oxygen consumption), fostering predictions of evolutionary changes in metabolic rates coupled with ecological shifts. One example of such correspondence is the evolution of fossoriality and nocturnality in vertebrate ectotherms, where changes in metabolic rates coupled with niche transitions are expected. Because most studies address single transitions (fossoriality or nocturnality), metabolic changes associated with concomitant shifts in spatial and temporal components of habitat usage are underestimated, and it remains unclear which transition plays a major role for metabolic evolution. Integrating multiple ecological aspects that affect the evolution of thermosensitive traits is essential for a proper understanding of physiological correlates in niche transitions. Here, we provide the first phylogenetic multidimensional description of effects from ecological niche transitions both in space (origin of fossorial lineages) and in time (origin of nocturnal lineages) on the evolution of microteiid lizard (Gymnophthalmidae) metabolic rates. We found that evolution of resting metabolic rates was affected by both niche transitions, but with opposite trends. Evolution of fossoriality in endemic diurnal microteiids is coupled with a less thermally sensitive metabolism and higher metabolic rates. In contrast, a reduction in metabolic rates was detected in the endemic fossorial-nocturnal lineage, although metabolic thermal sensitivity remained as high as that observed in epigeal species, a pattern that likely reduces locomotion costs at lower temperatures and also favors thermoregulation in subsuperficial sand layers.
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Affiliation(s)
- Melissa Bars-Closel
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil
| | - Agustín Camacho
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, 05422-970, São Paulo, SP, Brazil
| | - Tiana Kohlsdorf
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil
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16
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Sartori MR, Abe AS, Crossley DA, Taylor EW. Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana. Comp Biochem Physiol A Mol Integr Physiol 2017; 205:28-34. [DOI: 10.1016/j.cbpa.2016.12.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 10/20/2022]
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17
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Tattersall GJ. Reptile thermogenesis and the origins of endothermy. ZOOLOGY 2016; 119:403-405. [PMID: 27133734 DOI: 10.1016/j.zool.2016.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 11/16/2022]
Abstract
Extant endotherms have high rates of metabolism, elevated body temperatures, usually tight control over body temperature, and a reasonable scope for further increases in metabolism through locomotor activity. Vertebrate ectotherms, on the other hand, rely on behavioural thermoregulation and cardiovascular adjustments to facilitate warming, and generally lack specific biochemical and cellular mechanisms for sustained, elevated metabolism. Nevertheless, the ancestral condition to endothermy is thought to resemble that of many extant reptiles, which raises the question of the origins and selection pressures relevant to the transitional state. Numerous hypotheses have emerged to explain the multiple origins of endothermy in vertebrates, including thermoregulatory, locomotory, and reproductive activity as possible drivers for these sustained and elevated metabolic rates. In this article, I discuss recent evidence for facultative endothermy in an extant lepidosaur, the tegu lizard. Since lepidosaurs are a sister group to the archosaurs, understanding how a novel form of endothermy evolved will open up opportunities to test the compatibility or incompatibility of the various endothermy hypotheses, with potential to elucidate and resolve long contentious ideas in evolutionary physiology.
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Affiliation(s)
- Glenn J Tattersall
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S3A1, Canada.
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18
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Tattersall GJ, Leite CAC, Sanders CE, Cadena V, Andrade DV, Abe AS, Milsom WK. Seasonal reproductive endothermy in tegu lizards. SCIENCE ADVANCES 2016; 2:e1500951. [PMID: 26844295 PMCID: PMC4737272 DOI: 10.1126/sciadv.1500951] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as "true endotherms": the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy.
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Affiliation(s)
- Glenn J. Tattersall
- Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
| | - Cleo A. C. Leite
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
| | - Colin E. Sanders
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
| | - Viviana Cadena
- Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Denis V. Andrade
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, São Paulo State University (UNESP), 13506-900 Rio Claro, Brazil
| | - Augusto S. Abe
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, São Paulo State University (UNESP), 13506-900 Rio Claro, Brazil
| | - William K. Milsom
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
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19
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Zena LA, Dantonio V, Gargaglioni LH, Andrade DV, Abe AS, Bícego KC. Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard (Salvator merianae). J Exp Biol 2016; 219:725-33. [DOI: 10.1242/jeb.129130] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 12/17/2015] [Indexed: 11/20/2022]
Abstract
Baroreflex regulation of blood pressure (BP) is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (fH) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing fH along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of fH was studied at ∼25°C in spring-summer and winter-acclimated tegus.
In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3±0.82 vs 10.3±0.81 and 11.2±0.65 vs 7.97±0.88 beats.min−1), while no acclimation differences occurred in resting BP (5.14±0.38 vs 5.06±0.56 kPa), baroreflex gain (94.3±10.7 vs 138.7±30.3 %.kPa−1) and rate-pressure product (an index of myocardial activity). Vagal tone exceeded the sympathetic tone of fH especially in the winter group. Therefore, despite the lower fH, winter acclimation does not diminish the fH baroreflex responses nor rate-pressure product possibly because of increased stroke volume that may arise due to heart hypertrophy. Independent of acclimation, fH responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant fH reflex response to hypothension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods.
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Affiliation(s)
- Lucas A. Zena
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, 14884-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
| | - Valter Dantonio
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, 14884-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
| | - Luciane H. Gargaglioni
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, 14884-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
| | - Denis V. Andrade
- Department of Zoology, Institute of Bioscience, São Paulo State University, Rio Claro, São Paulo, 13506-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
| | - Augusto S. Abe
- Department of Zoology, Institute of Bioscience, São Paulo State University, Rio Claro, São Paulo, 13506-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
| | - Kênia C. Bícego
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo, 14884-900, Brazil
- National Institute of Science and Technology – Comparative Physiology (INCT- Fisiologia Comparada), Brazil
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20
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Sanders CE, Tattersall GJ, Reichert M, Andrade DV, Abe AS, Milsom WK. Daily and annual cycles in thermoregulatory behaviour and cardio-respiratory physiology of black and white tegu lizards. J Comp Physiol B 2015; 185:905-15. [PMID: 26266400 DOI: 10.1007/s00360-015-0928-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/08/2015] [Accepted: 07/31/2015] [Indexed: 11/25/2022]
Abstract
This study was designed to determine the manner in which metabolism is suppressed during dormancy in black and white tegu lizards (Tupinambis merianae). To this end, heart rate (fH), respiration rate (fR), and deep body temperature (Tb) were continuously monitored in outdoor enclosures by radio-telemetry for nine months. There was a continuous decline in nighttime breathing and heart rate, at constant Tb, throughout the late summer and fall suggestive of an active metabolic suppression that developed progressively at night preceding the entrance into dormancy. During the day, however, the tegus still emerged to bask. In May, when the tegus made a behavioural commitment to dormancy, Tb (day and night) fell to match burrow temperature, accompanied by a further reduction in fH and fR. Tegus, under the conditions of this study, did arouse periodically during dormancy. There was a complex interplay between changes in fH and Tb associated with the direct effects of temperature and the indirect effects of thermoregulation, activity, and changes in metabolism. This interplay gave rise to a daily hysteresis in the fH/Tb relationship reflective of the physiological changes associated with warming and cooling as preferred Tb alternated between daytime and nighttime levels. The shape of the hysteresis curve varied with season along with changes in metabolic state and daytime and nighttime body temperature preferences.
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Affiliation(s)
- Colin E Sanders
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
| | - Glenn J Tattersall
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada
| | - Michelle Reichert
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
| | - Denis V Andrade
- Depto de Zoologia, Instituto Nacional de Ciência e Tecnologia em Fisiologia Comparada, Univ Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Augusto S Abe
- Depto de Zoologia, Instituto Nacional de Ciência e Tecnologia em Fisiologia Comparada, Univ Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - William K Milsom
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada.
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