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Roe JH. Spatial Ecology, Movements, and Habitat Selection of Clemmys guttata in a Temporally Dynamic Wetland System in North Carolina, USA. Herpetol Conserv Biol 2023; 18:140-154. [PMID: 37981954 PMCID: PMC10655762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Turtle populations are in decline worldwide, requiring immediate conservation and management actions. For species with broad geographic ranges that cover diverse environmental contexts, region-specific information on declining species could inform more targeted management plans. I examined the ecology of a Spotted Turtle (Clemmys guttata) population in a temporally dynamic wetland system in the Southeastern Plains ecoregion of North Carolina. Turtles selected forested wetlands and streams while avoiding open wetlands and river habitats, but used terrestrial habitats minimally and randomly. Turtles responded to wetland drying by remaining in wetlands and maintaining modest levels of activity during short-duration drying events (< 1 mo), but moved very little during longer droughts (7 mo). Turtles had prolonged active seasons (February-October) as long as wetlands and streams were flooded, with movement rates peaking in late spring at 23.6 ± 3.7 m/d (mean ± standard error). Turtles had large home ranges (14.1 ± 4.3 ha) that often included multiple local stream networks used as movement corridors between forested wetland patches and as activity centers when wetlands dried. I suggest that conservation plans for C. guttata include large management areas that protect a network of streams and adjacent forested swamps in the Southeastern Plains and perhaps other lowland ecoregions in the Southeastern U.S. Because terrestrial habitats were not used for extended refuge during drought, certain low-impact land uses in adjacent terrestrial areas are not likely to negatively impact C. guttata populations, but terrestrial forests would still be important in maintaining overland travel corridors.
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Affiliation(s)
- John H Roe
- Department of Biology, University of North Carolina Pembroke, One University Drive, Pembroke, North Carolina 28372, USA
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2
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Moreira DC, Wang Y, López-Martínez G, Hermes-Lima M. Editorial: Redox Metabolism in Environmental and Ecological Physiology of Animals. Front Physiol 2022; 13:904746. [PMID: 35547571 PMCID: PMC9081337 DOI: 10.3389/fphys.2022.904746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 11/25/2022] Open
Affiliation(s)
- Daniel C Moreira
- Research Center on Morphology and Applied Immunology, Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Youji Wang
- International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, Shanghai, China
| | | | - Marcelo Hermes-Lima
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
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3
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Tanwar AK, Kirti JS, Kumar S, Dhillon MK. The amino acid and lipophilic profiles of Chilo partellus (Swinhoe) larvae fluctuate with diapause. J Exp Zool A Ecol Integr Physiol 2021; 335:595-601. [PMID: 34185965 DOI: 10.1002/jez.2502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/05/2021] [Accepted: 06/16/2021] [Indexed: 11/10/2022]
Abstract
The Chilo partellus (Crambidae: Lepidoptera) larvae undergoes both hibernation and estivation in India. Although, much has been done on reproductive physiological aspects, little is known about biochemical changes happening during hibernation and estivation in C. partellus. Thus, we mapped changes in amino acid and lipophilic profiles of C. partellus larvae while undergoing hibernation and estivation using high-performance liquid chromatography and gas chromatography mass spectroscopy. The studies revealed higher amounts of amino acids namely, serine, glycine, histidine, arginine, proline, tyrosine, and methionine in estivation, while lower in hibernation as compared with nondiapause larvae of C. partellus. Furthermore, the amounts of aspartic acid, glutamic acid, and alanine in hibernation, and threonine, valine, isoleucine, phenylalanine, and leucine in estivation were on par with nondiapause larvae. The lipophilic compounds namely, linoleic acid, stearic acid, eicosanoic acid, and n-pentadecanol were lower in hibernation than estivation and nondiapause larvae of C. partellus. Palmitoleic acid and methyl 3-methoxytetradecanoate contents were higher in hibernation than estivation and nondiapause, while myristic acid and lathosterol contents were higher in estivation than hibernation and nondiapause larvae of C. partellus. Cholesterol content was higher, while squalene and gamma-ergostenol were lower in hibernation and estivation as compared with nondiapause larvae of C. partellus. These findings suggest that certain amino acids may be constituents of heat-shock proteins and help C. partellus during estivation. However, the lipophilic compounds could be helpful in maintaining development during hibernation and estivation in C. partellus.
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Affiliation(s)
- Aditya K Tanwar
- Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi, India.,Department of Zoology and Environmental Sciences, Punjabi University, Patiala, Punjab, India
| | - Jagbir S Kirti
- Department of Zoology and Environmental Sciences, Punjabi University, Patiala, Punjab, India
| | - Sandeep Kumar
- Biochemistry Laboratory, ICAR-National Bureau of Plant Genetic Resources, New Delhi, India
| | - Mukesh K Dhillon
- Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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4
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Abstract
The mechanistic target of rapamycin (mTOR) is a central regulator of cellular homeostasis that integrates environmental and nutrient signals to control cell growth and survival. Over the past two decades, extensive studies of mTOR have implicated the importance of this protein complex in regulating a broad range of metabolic functions, as well as its role in the progression of various human diseases. Recently, mTOR has emerged as a key signaling molecule in regulating animal entry into a hypometabolic state as a survival strategy in response to environmental stress. Here, we review current knowledge of the role that mTOR plays in contributing to natural hypometabolic states such as hibernation, estivation, hypoxia/anoxia tolerance, and dauer diapause. Studies across a diverse range of animal species reveal that mTOR exhibits unique regulatory patterns in an environmental stressor-dependent manner. We discuss how key signaling proteins within the mTOR signaling pathways are regulated in different animal models of stress, and describe how each of these regulations uniquely contribute to promoting animal survival in a hypometabolic state.
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Affiliation(s)
- Cheng-Wei Wu
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
- Correspondence:
| | - Kenneth B. Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada;
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5
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Olsen L, Thum E, Rohner N. Lipid metabolism in adaptation to extreme nutritional challenges. Dev Cell 2021; 56:1417-29. [PMID: 33730548 DOI: 10.1016/j.devcel.2021.02.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/11/2021] [Accepted: 02/19/2021] [Indexed: 02/06/2023]
Abstract
Food shortages represent a common challenge for most animal species. As a consequence, many have evolved metabolic strategies encompassing extreme starvation-resistance capabilities, going without food for months or even years. One such strategy is to store substantial levels of fat when food is available and release these energy-rich lipids during periods of dearth. In this review, we provide an overview of the strategies and pathways underlying the extreme capacity for animals to store and mobilize lipids during nutritionally stressful environmental conditions and highlight accompanying resilience phenotypes that allow these animals to develop and tolerate such profound metabolic phenotypes.
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6
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Minegishi S, Luft FC, Titze J, Kitada K. Sodium Handling and Interaction in Numerous Organs. Am J Hypertens 2020; 33:687-694. [PMID: 32198504 DOI: 10.1093/ajh/hpaa049] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/10/2020] [Accepted: 03/17/2020] [Indexed: 12/27/2022] Open
Abstract
Salt (NaCl) is a prerequisite for life. Excessive intake of salt, however, is said to increase disease risk, including hypertension, arteriosclerosis, heart failure, renal disease, stroke, and cancer. Therefore, considerable research has been expended on the mechanism of sodium handling based on the current concepts of sodium balance. The studies have necessarily relied on relatively short-term experiments and focused on extremes of salt intake in humans. Ultra-long-term salt balance has received far less attention. We performed long-term salt balance studies at intakes of 6, 9, and 12 g/day and found that although the kidney remains the long-term excretory gate, tissue and plasma sodium concentrations are not necessarily the same and that urinary salt excretion does not necessarily reflect total-body salt content. We found that to excrete salt, the body makes a great effort to conserve water, resulting in a natriuretic-ureotelic principle of salt excretion. Of note, renal sodium handling is characterized by osmolyte excretion with anti-parallel water reabsorption, a state-of-affairs that is achieved through the interaction of multiple organs. In this review, we discuss novel sodium and water balance concepts in reference to our ultra-long-term study. An important key to understanding body sodium metabolism is to focus on water conservation, a biological principle to protect from dehydration, since excess dietary salt excretion into the urine predisposes to renal water loss because of natriuresis. We believe that our research direction is relevant not only to salt balance but also to cardiovascular regulatory mechanisms.
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Affiliation(s)
- Shintaro Minegishi
- Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Friedrich C Luft
- Experimental & Clinical Research Center, a joint collaboration between Max-Delbrück Center for Molecular Medicine and Charité Universitätsmedizin, Berlin, Germany
| | - Jens Titze
- Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina, USA
- Division of Nephrology and Hypertension, University Clinic Erlangen, Erlangen, Germany
| | - Kento Kitada
- Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore
- JSPS Overseas Research Fellow, Japan Society for the Promotion of Science, Tokyo, Japan
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7
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Schweizer M, Triebskorn R, Köhler H. Snails in the sun: Strategies of terrestrial gastropods to cope with hot and dry conditions. Ecol Evol 2019; 9:12940-12960. [PMID: 31788227 PMCID: PMC6875674 DOI: 10.1002/ece3.5607] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/15/2019] [Accepted: 08/05/2019] [Indexed: 11/08/2022] Open
Abstract
Terrestrial gastropods do not only inhabit humid and cool environments but also habitat in which hot and dry conditions prevail. Snail species that are able to cope with such climatic conditions are thus expected to having developed multifaceted strategies and mechanisms to ensure their survival and reproduction under heat and desiccation stress. This review paper aims to provide an integrative overview of the numerous adaptation strategies terrestrial snails have evolved to persist in hot and dry environments as well as their mutual interconnections and feedbacks, but also to outline research gaps and questions that remained unanswered. We extracted relevant information from more than 140 publications in order to show how biochemical, cellular, physiological, morphological, ecological, thermodynamic, and evolutionary parameters contribute to provide an overall picture of this classical example in stress ecology. These mechanisms range from behavioral and metabolic adaptations, including estivation, to the induction of chaperones and antioxidant enzymes, mucocyte and digestive gland cell responses and the modification and frequency of morphological features, particularly shell pigmentation. In this context, thermodynamic constraints call for processes of complex adaptation at varying levels of biological organization that are mutually interwoven. We were able to assemble extensive, mostly narrowly focused information from the literature into a web of network parameters, showing that future work on this subject requires multicausal thinking to account for the complexity of relationships involved in snails' adaptation to insolation, heat, and drought.
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Affiliation(s)
- Mona Schweizer
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
| | - Rita Triebskorn
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
- Steinbeis Transfer Center for Ecotoxicology and EcophysiologyRottenburgGermany
| | - Heinz‐R. Köhler
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
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8
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Faber-Hammond JJ, Coyle KP, Bacheller SK, Roberts CG, Mellies JL, Roberts RB, Renn SCP. The intestinal environment as an evolutionary adaptation to mouthbrooding in the Astatotilapia burtoni cichlid. FEMS Microbiol Ecol 2019; 95:5315751. [PMID: 30753545 DOI: 10.1093/femsec/fiz016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 02/08/2019] [Indexed: 12/13/2022] Open
Abstract
Many of the various parental care strategies displayed by animals are accompanied by a significant reduction in food intake that imposes a substantial energy trade-off. Mouthbrooding, as seen in several species of fish in which the parent holds the developing eggs and fry in the buccal cavity, represents an extreme example of reduced food intake during parental investment and is accompanied by a range of physiological adaptations. In this study we use 16S sequencing to characterize the gut microbiota of female Astatotilapia burtoni cichlid fish throughout the obligatory phase of self-induced starvation during the brooding cycle in comparison to stage-matched females that have been denied food for the same duration. In addition to a reduction of gut epithelial turnover, we find a dramatic reduction in species diversity in brooding stages that recovers upon release of fry and refeeding that is not seen in females that are simply starved. Based on overall species diversity as well as differential abundance of specific bacterial taxa, we suggest that rather than reflecting a simple deprivation of caloric intake, the gut microbiota is more strongly influenced by physiological changes specific to mouthbrooding including the reduced epithelial turnover and possible production of antimicrobial agents.
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Affiliation(s)
| | - Kaitlin P Coyle
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, 3510 Thomas Hall, 112 Derieux Place, North Carolina State University, Raleigh, NC, USA
| | | | | | - Jay L Mellies
- Department of Biology, Reed College, Portland, Oregon, USA
| | - Reade B Roberts
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, 3510 Thomas Hall, 112 Derieux Place, North Carolina State University, Raleigh, NC, USA
| | - Suzy C P Renn
- Department of Biology, Reed College, Portland, Oregon, USA
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9
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Oliveira MF, Geihs MA, França TFA, Moreira DC, Hermes-Lima M. Is "Preparation for Oxidative Stress" a Case of Physiological Conditioning Hormesis? Front Physiol 2018; 9:945. [PMID: 30116197 PMCID: PMC6082956 DOI: 10.3389/fphys.2018.00945] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/28/2018] [Indexed: 01/01/2023] Open
Affiliation(s)
- Marcus F Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcio A Geihs
- Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil
| | - Thiago F A França
- Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil
| | - Daniel C Moreira
- Área de Morfologia, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil.,Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasilia, Brazil
| | - Marcelo Hermes-Lima
- Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasilia, Brazil
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10
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Moreira DC, Oliveira MF, Liz-Guimarães L, Diniz-Rojas N, Campos ÉG, Hermes-Lima M. Corrigendum: Current Trends and Research Challenges Regarding "Preparation for Oxidative Stress". Front Physiol 2018; 9:950. [PMID: 30042698 PMCID: PMC6053941 DOI: 10.3389/fphys.2018.00950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 06/28/2018] [Indexed: 11/25/2022] Open
Affiliation(s)
- Daniel C Moreira
- Departamento de Biologia Celular, Universidade de Brasília, Brasilia, Brazil.,Área de Morfologia, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Marcus F Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lara Liz-Guimarães
- Departamento de Biologia Celular, Universidade de Brasília, Brasilia, Brazil
| | - Nilda Diniz-Rojas
- Departamento de Genética e Morfologia, Universidade de Brasília, Brasilia, Brazil
| | - Élida G Campos
- Departamento de Biologia Celular, Universidade de Brasília, Brasilia, Brazil
| | - Marcelo Hermes-Lima
- Departamento de Biologia Celular, Universidade de Brasília, Brasilia, Brazil
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11
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Moreira DC, Oliveira MF, Liz-Guimarães L, Diniz-Rojas N, Campos ÉG, Hermes-Lima M. Current Trends and Research Challenges Regarding "Preparation for Oxidative Stress". Front Physiol 2017; 8:702. [PMID: 28993737 PMCID: PMC5622305 DOI: 10.3389/fphys.2017.00702] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/31/2017] [Indexed: 12/26/2022] Open
Abstract
Survival under stress, such as exposure to hypoxia, anoxia, freezing, dehydration, air exposure of water breathing organisms, and estivation, is commonly associated to enhanced endogenous antioxidants, a phenomenon coined "preparation for oxidative stress" (POS). The regulation of free radical metabolism seems to be crucial under these selective pressures, since this response is widespread among animals. A hypothesis of how POS works at the molecular level was recently proposed and relies on two main processes: increased reactive species production under hypoxia, and activation of redox-sensitive transcription factors and signaling pathways, increasing the expression of antioxidants. The present paper brings together the current knowledge on POS and considers its future directions. Data indicate the presence of POS in 83 animal species (71.6% among investigated species), distributed in eight animal phyla. Three main research challenges on POS are presented: (i) to identify the molecular mechanism(s) that mediate/induce POS, (ii) to identify the evolutionary origins of POS in animals, and (iii) to determine the presence of POS in natural environments. We firstly discuss the need of evidence for increased RS production in hypoxic conditions that underlie the POS response. Secondly, we discuss the phylogenetic origins of POS back 700 million years, by identifying POS-positive responses in cnidarians. Finally, we present the first reports of the POS adaptation strategy in the wild. The investigation of these research trends and challenges may prove useful to understand the evolution of animal redox adaptations and how they adapt to increasing stressful environments on Earth.
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Affiliation(s)
- Daniel C. Moreira
- Departamento de Biologia Celular, Universidade de BrasíliaBrasilia, Brazil
- Área de Morfologia, Faculdade de Medicina, Universidade de BrasíliaBrasilia, Brazil
| | - Marcus F. Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Lara Liz-Guimarães
- Departamento de Biologia Celular, Universidade de BrasíliaBrasilia, Brazil
| | - Nilda Diniz-Rojas
- Departamento de Genética e Morfologia, Universidade de BrasíliaBrasilia, Brazil
| | - Élida G. Campos
- Departamento de Biologia Celular, Universidade de BrasíliaBrasilia, Brazil
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12
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Warrant E, Frost B, Green K, Mouritsen H, Dreyer D, Adden A, Brauburger K, Heinze S. Corrigendum: The Australian Bogong Moth Agrotis infusa: A Long-Distance Nocturnal Navigator. Front Behav Neurosci 2017; 11:162. [PMID: 28878637 PMCID: PMC5582608 DOI: 10.3389/fnbeh.2017.00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 08/16/2017] [Indexed: 11/13/2022] Open
Abstract
[This corrects the article on p. 77 in vol. 10, PMID: 27147998.].
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Affiliation(s)
- Eric Warrant
- Lund Vision Group, Department of Biology, University of LundLund, Sweden
| | - Barrie Frost
- Department of Psychology, Queens UniversityKingston, ON, Canada
| | - Ken Green
- New South Wales National Parks and Wildlife ServiceJindabyne, NSW, Australia
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, University of OldenburgOldenburg, Germany
| | - David Dreyer
- Lund Vision Group, Department of Biology, University of LundLund, Sweden
| | - Andrea Adden
- Lund Vision Group, Department of Biology, University of LundLund, Sweden
| | | | - Stanley Heinze
- Lund Vision Group, Department of Biology, University of LundLund, Sweden
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13
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Wu CW, Tessier SN, Storey KB. Regulation of the insulin-Akt signaling pathway and glycolysis during dehydration stress in the African clawed frog Xenopus laevis. Biochem Cell Biol 2017; 95:663-671. [PMID: 28708941 DOI: 10.1139/bcb-2017-0117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Estivation is an adaptive stress response utilized by some amphibians during periods of drought in the summer season. In this study, we examine the regulation of the insulin signaling cascade and glycolysis pathway in the African clawed frog Xenopus laevis during the dehydration stress induced state of estivation. We show that in the brain and heart of X. laevis, dehydration reduces the phosphorylation of the insulin growth factor-1 receptor (IGF-1R), and this is followed by similar reductions in the phosphorylation of the Akt and mechanistic target of rapamycin (mTOR) kinase. Interestingly, phosphorylation levels of IGF-1R and mTOR were not affected in the kidney, and phosphorylation levels of P70S6K and the ribosomal S6 protein were elevated during dehydration stress. Animals under estivation are also susceptible to periods of hypoxia, suggesting that glycolysis may also be affected. We observed that protein levels of many glycolytic enzymes remained unchanged during dehydration; however, the hypoxia response factor-1 alpha (HIF-1α) protein was elevated by greater than twofold in the heart during dehydration. Overall, we provide evidence that shows that the insulin signaling pathway in X. laevis is regulated in a tissue-specific manner during dehydration stress and suggests an important role for this signaling cascade in mediating the estivation response.
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Affiliation(s)
- Cheng-Wei Wu
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada.,Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada
| | - Shannon N Tessier
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada.,Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada.,Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada
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Abstract
Species of Amphiuma enter a state of subterranean estivation with the drying of their aquatic habitat. Characteristic of amphibian fasting and estivation is an initial depression of metabolism and tissue mass and function with fasting, followed by a more pronounced adaptive decrease in metabolism and tissue function with estivation. We hypothesized that Amphiuma likewise experiences a two-stage set of responses to estivation. Therefore, we examined the physiological responses of the three-toed amphiuma (Amphiuma tridactylum) to fasting and estivation treatments. Recently fed A. tridactylum served as controls for fasting treatments of 1, 3, and 6 mo (in water) and estivation treatments of 3 and 6 mo (buried in dried substrate). After a 1-mo fast, A. tridactylum experienced no further depression of metabolic rate following 3 or 6 mo of fasting or estivation. For all fasting and estivation trials, A. tridactylum maintained blood chemistry homeostasis, with the exception of an increase in blood urea following 6 mo of estivation. Compared with fed controls, the mass of most organs did not vary even after 6 mo of fasting and estivation. Only the small intestine (decreasing) and the full gall bladder (increasing) experienced significant changes in mass with fasting or estivation. The fasting decrease in small intestinal mass was in part due to enterocyte atrophy, which resulted in a decrease in mucosa/submucosa thickness. In contrast to many estivating anurans and the ecologically convergent sirens, A. tridactylum does not surround itself in a cocoon of dried skin or mucus during estivation. The thickness and architecture of their skin remains unchanged even after 6 mo of estivation. Following months of fasting or estivation, individuals still maintain gastric acid production, pancreatic enzyme activity, and intestinal enzyme and transporter activities. Contrary to our hypothesis that A. tridactylum experiences two stages of metabolic depression and tissue downregulation, first with fasting and second with estivation, we observed a relatively modest single-stage response to both. Rather than becoming dormant and engaging in mechanisms to depress metabolism and tissue performance with estivation, A. tridactylum employs an alternative strategy of remaining alert and possibly eating to survive extended periods when their aquatic habitats become dry.
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15
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Warrant E, Frost B, Green K, Mouritsen H, Dreyer D, Adden A, Brauburger K, Heinze S. The Australian Bogong Moth Agrotis infusa: A Long-Distance Nocturnal Navigator. Front Behav Neurosci 2016; 10:77. [PMID: 27147998 PMCID: PMC4838632 DOI: 10.3389/fnbeh.2016.00077] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/04/2016] [Indexed: 02/03/2023] Open
Abstract
The nocturnal Bogong moth (Agrotis infusa) is an iconic and well-known Australian insect that is also a remarkable nocturnal navigator. Like the Monarch butterflies of North America, Bogong moths make a yearly migration over enormous distances, from southern Queensland, western and northwestern New South Wales (NSW) and western Victoria, to the alpine regions of NSW and Victoria. After emerging from their pupae in early spring, adult Bogong moths embark on a long nocturnal journey towards the Australian Alps, a journey that can take many days or even weeks and cover over 1000 km. Once in the Alps (from the end of September), Bogong moths seek out the shelter of selected and isolated high ridge-top caves and rock crevices (typically at elevations above 1800 m). In hundreds of thousands, moths line the interior walls of these cool alpine caves where they “hibernate” over the summer months (referred to as “estivation”). Towards the end of the summer (February and March), the same individuals that arrived months earlier leave the caves and begin their long return trip to their breeding grounds. Once there, moths mate, lay eggs and die. The moths that hatch in the following spring then repeat the migratory cycle afresh. Despite having had no previous experience of the migratory route, these moths find their way to the Alps and locate their estivation caves that are dotted along the high alpine ridges of southeastern Australia. How naïve moths manage this remarkable migratory feat still remains a mystery, although there are many potential sensory cues along the migratory route that moths might rely on during their journey, including visual, olfactory, mechanical and magnetic cues. Here we review our current knowledge of the Bogong moth, including its natural history, its ecology, its cultural importance to the Australian Aborigines and what we understand about the sensory basis of its long-distance nocturnal migration. From this analysis it becomes clear that the Bogong moth represents a new and very promising model organism for understanding the sensory basis of nocturnal migration in insects.
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Affiliation(s)
- Eric Warrant
- Lund Vision Group, Department of Biology, University of Lund Lund, Sweden
| | - Barrie Frost
- Department of Psychology, Queens University Kingston, ON, Canada
| | - Ken Green
- New South Wales National Parks and Wildlife Service Jindabyne, NSW, Australia
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, University of Oldenburg Oldenburg, Germany
| | - David Dreyer
- Lund Vision Group, Department of Biology, University of Lund Lund, Sweden
| | - Andrea Adden
- Lund Vision Group, Department of Biology, University of Lund Lund, Sweden
| | | | - Stanley Heinze
- Lund Vision Group, Department of Biology, University of Lund Lund, Sweden
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