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de Almeida Prado DM, de Figueiredo AC, Lima AS, Gomes FR, Madelaire CB. Corticosterone treatment results in fat deposition and body mass maintenance without effects on feeding behaviour or immunity in female lizards (Tropidurus catalanensis). Comp Biochem Physiol A Mol Integr Physiol 2024; 297:111712. [PMID: 39084515 DOI: 10.1016/j.cbpa.2024.111712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 07/24/2024] [Accepted: 07/24/2024] [Indexed: 08/02/2024]
Abstract
Throughout life, animals must maintain homeostasis while coping with challenging events. The period after reproduction can be challenging for oviparous females to maintain homeostasis since they direct most of their energy stores to vitellogenesis, possibly increasing the vulnerability to stressors. Changes in glucocorticoids' (GC) secretion promote various behavioural and physiological adjustments daily and to restore balance after facing stressors. However, when GC are elevated for extended periods, which usually occurs in response to chronic exposure to stressors, they can affect feeding behaviour and suppress the immune function. We aim to elucidate the effects of chronic corticosterone (CORT) exposure on feeding behaviour, body condition and immune function in female lizards, Tropidurus catalanensis, in the post-reproductive period. Thirty animals were divided into three groups: 1. Control (no experimental procedure performed); 2. Empty Implant (animals implanted with empty silastic tube); and 3. CORT Implant (animals implanted with silastic tube filled with CORT, with a chronic continuous release for at least a week). CORT plasma levels feeding behaviour, body condition (body index [BI] and fat index [FI]), leukocyte count, and several immune function variables (bacterial killing ability [BKA], hemagglutination titer, phytohemagglutinin [PHA] immune challenge and leukocyte count) were evaluated. After implantation, CORT treated animals maintained stable body mass through the experiment, while Control and Empty Implant groups displayed weight loss. In the CORT treated animals, there was also a positive relation between BI and FI, and higher FI when compared to groups 1 and 2. No effects of CORT were observed on feeding behaviour nor on the immune function.
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Affiliation(s)
- Débora Meyer de Almeida Prado
- USP - Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, Travessa 14, n° 321, Cidade Universitária, São Paulo, SP 05508090, Brazil.
| | - Aymam Cobo de Figueiredo
- USP - Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, Travessa 14, n° 321, Cidade Universitária, São Paulo, SP 05508090, Brazil
| | - Alan Siqueira Lima
- USP - Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, Travessa 14, n° 321, Cidade Universitária, São Paulo, SP 05508090, Brazil
| | - Fernando Ribeiro Gomes
- USP - Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, Travessa 14, n° 321, Cidade Universitária, São Paulo, SP 05508090, Brazil
| | - Carla Bonetti Madelaire
- Beckman Center for Conservation Research, San Diego Zoo Wildlife Alliance, Escondido, CA 92027, United States. https://twitter.com/carlamadelaire
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Palacios-Marquez JJ, Guevara-Fiore P. Parasitism in viviparous vertebrates: an overview. Parasitol Res 2023; 123:53. [PMID: 38100003 DOI: 10.1007/s00436-023-08083-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023]
Abstract
The reproductive mode of viviparity has independently evolved in various animal taxa. It refers to the condition in which the embryos or young develop inside the female's body during gestation, providing advantages such as protection, nutrition, and improved survival chances. However, parasites and diseases can be an evolutionary force that limit the host's resources, leading to physiological, morphological, and behavioral changes that impose additional costs on both the pregnant female and her offspring. This review integrates the primary literature published between 1980 and 2021 on the parasitism of viviparous hosts. We describe aspects such as reproductive investment in females, offspring sex ratios, lactation investment in mammals, alterations in birth intervals, current reproductive investment, variations between environments, immune system activity in response to immunological challenges, and other factors that can influence the interaction between viviparous females and parasites. Maintaining pregnancy incurs costs in managing the mother's resources and regulating the immune system's responses to the offspring, while simultaneously maintaining an adequate defense against parasites and pathogens. Parasites can significantly influence this reproductive mode: parasitized females adjust their investment in survival and reproduction based on their life history, environmental factors, and the diversity of encountered parasites.
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Affiliation(s)
- Juan J Palacios-Marquez
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Blvd. Valsequillo y Av. San Claudio, Edificio Bio-1, Ciudad Universitaria, Col. Jardines de San Manuel, 72580, Puebla, CP, Mexico
| | - Palestina Guevara-Fiore
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Blvd. Valsequillo y Av. San Claudio, Edificio Bio-1, Ciudad Universitaria, Col. Jardines de San Manuel, 72580, Puebla, CP, Mexico.
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3
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Phenological variation in parasite load and inflammatory response in a lizard with an asynchronous reproductive cycle. Naturwissenschaften 2022; 109:34. [DOI: 10.1007/s00114-022-01793-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 03/12/2022] [Accepted: 03/21/2022] [Indexed: 10/17/2022]
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Hudson SB, Virgin EE, Kepas ME, French SS. Energy expenditure across immune challenge severities in a lizard: consequences for innate immunity, locomotor performance and oxidative status. J Exp Biol 2021; 224:271845. [PMID: 34402514 DOI: 10.1242/jeb.242608] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/11/2021] [Indexed: 12/15/2022]
Abstract
Reptiles, like other vertebrates, rely on immunity to defend themselves from infection. The energetic cost of an immune response is liable to scale with infection severity, prompting constraints on other self-maintenance traits if immune prioritization exceeds energy budget. In this study, adult male side-blotched lizards (Uta stansburiana) were injected with saline (control) or high (20 µg g-1 body mass) or low (10 µg g-1 body mass) concentrations of lipopolysaccharide (LPS) to simulate bacterial infections of discrete severities. The costs and consequences of the immune response were assessed through comparisons of change in resting metabolic rate (RMR), energy metabolites (glucose, glycerol, triglycerides), innate immunity (bactericidal ability), sprint speed and oxidative status (antioxidant capacity, reactive oxygen metabolites). High-LPS lizards had the lowest glucose levels and greatest sprint reductions, while their RMR and bactericidal ability were similar to those of control lizards. Low-LPS lizards had elevated RMR and bactericidal ability, but glucose levels and sprint speed changes between those of high-LPS and control lizards. Levels of glycerol, triglycerides, reactive oxygen metabolites and antioxidant capacity did not differ by treatment. Taken together, energy expenditure for the immune response varies in a non-linear fashion with challenge severity, posing consequences for performance and self-maintenance processes in a reptile.
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Affiliation(s)
- Spencer B Hudson
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Emily E Virgin
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Megen E Kepas
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Susannah S French
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
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Polinski MP, Zhang Y, Morrison PR, Marty GD, Brauner CJ, Farrell AP, Garver KA. Innate antiviral defense demonstrates high energetic efficiency in a bony fish. BMC Biol 2021; 19:138. [PMID: 34253202 PMCID: PMC8276435 DOI: 10.1186/s12915-021-01069-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/09/2021] [Indexed: 11/18/2022] Open
Abstract
Background Viruses can impose energetic demands on organisms they infect, in part by hosts mounting resistance. Recognizing that oxygen uptake reliably indicates steady-state energy consumption in all vertebrates, we comprehensively evaluated oxygen uptake and select transcriptomic messaging in sockeye salmon challenged with either a virulent rhabdovirus (IHNV) or a low-virulent reovirus (PRV). We tested three hypotheses relating to the energetic costs of viral resistance and tolerance in this vertebrate system: (1) mounting resistance incurs a metabolic cost or limitation, (2) induction of the innate antiviral interferon system compromises homeostasis, and (3) antiviral defenses are weakened by acute stress. Results IHNV infections either produced mortality within 1–4 weeks or the survivors cleared infections within 1–9 weeks. Transcription of three interferon-stimulated genes (ISGs) was strongly correlated with IHNV load but not respiratory performance. Instead, early IHNV resistance was associated with a mean 19% (95% CI = 7–31%; p = 0.003) reduction in standard metabolic rate. The stress of exhaustive exercise did not increase IHNV transcript loads, but elevated host inflammatory transcriptional signaling up to sevenfold. For PRV, sockeye tolerated high-load systemic PRV blood infections. ISG transcription was transiently induced at peak PRV loads without associated morbidity, microscopic lesions, or major changes in aerobic or anaerobic respiratory performance, but some individuals with high-load blood infections experienced a transient, minor reduction in hemoglobin concentration and increased duration of excess post-exercise oxygen consumption. Conclusions Contrary to our first hypothesis, effective resistance against life-threatening rhabdovirus infections or tolerance to high-load reovirus infections incurred minimal metabolic costs to salmon. Even robust systemic activation of the interferon system did not levy an allostatic load sufficient to compromise host homeostasis or respiratory performance, rejecting our second hypothesis that this ancient innate vertebrate antiviral defense is itself energetically expensive. Lastly, an acute stress experienced during testing did not weaken host antiviral defenses sufficiently to promote viral replication; however, a possibility for disease intensification contingent upon underlying inflammation was indicated. These data cumulatively demonstrate that fundamental innate vertebrate defense strategies against potentially life-threatening viral exposure impose limited putative costs on concurrent aerobic or energetic demands of the organism. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01069-2.
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Affiliation(s)
- Mark P Polinski
- Fisheries and Oceans Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada.
| | - Yangfan Zhang
- Faculty of Land and Food Systems, University of British Columbia, MCML 344-2357 Main Mall, Vancouver, V6T1Z4, Canada
| | - Phillip R Morrison
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Gary D Marty
- Animal Health Centre, Ministry of Agriculture, Food and Fisheries, 1767 Angus Campbell Rd, Abbotsford, V3G2M3, Canada
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Anthony P Farrell
- Faculty of Land and Food Systems, University of British Columbia, MCML 344-2357 Main Mall, Vancouver, V6T1Z4, Canada.,Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Kyle A Garver
- Fisheries and Oceans Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada.
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Madelaire CB, Zena LA, Dillon D, Silva DP, Hunt KE, Loren Buck C, Bícego KC, Gomes FR. Who rules over immunology? Sseasonal variation in body temperature,, steroid hormones, and immune variables in a tegu lizard. Integr Comp Biol 2021; 61:1867-1880. [PMID: 34022037 DOI: 10.1093/icb/icab093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Multiple factors can influence the immune response of ectothermic vertebrates, including body temperature, gonadal steroids, and seasonality, in ways that are thought to reflect trade-offs between energetic investment in immunity vs. reproduction. Hibernating tegu lizards (Salvator merianae) are a unique model to investigate how immunocompetence might be influenced by different factors during their annual cycle. We assessed immunological measures (plasma bacterial killing ability, total and differential leukocyte count), plasma hormone levels (testosterone in males, estradiol and progesterone in females, and corticosterone in both sexes), body temperature, and body condition from adult tegus during each stage of their annual cycle: reproduction, post-reproduction/preparation for hibernation, and hibernation. Our hypothesis that immune traits present higher values during the reproductive phase, and a sharp decrease during hibernation, was partially supported. Immune variables did not change between life history stages, except for total number of leukocytes, which was higher at the beginning of the reproductive season (September) in both males and females. Average body temperature of the week prior to sampling was positively correlated with number of eosinophils, basophils, monocytes and azurophils, corroborating other studies showing that when animals maintain a high Tb, there is an increase in immune activity. Surprisingly, no clear relationship between immune traits and gonadal steroids or corticosterone levels was observed, even when including life history stage in the model. When gonadal hormones peaked in males and females, heterophil:lymphocyte ratio (which often elevates during physiological stress) also increased. Additionally, we did not observe any trade-off between reproduction and immunity traits, sex differences in immune traits or a correlation between body condition and immune response. Our results suggest that variation in patterns of immune response and correlations with body condition and hormone secretion across the year can depend upon the specific hormone and immune trait, and that experienced Tb is an important variable determining immune response in ectotherms.
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Affiliation(s)
- Carla B Madelaire
- Department of Biological Sciences, Northern Arizona University, 1899 S San Francisco St, Flagstaff, AZ, 86001, USA.,Department of Physiology, Institute of Biosciences, University of São Paulo, Trav. 14 da Rua do Matão, 321, São Paulo, SP, 05508-090, Brazil
| | - Lucas A Zena
- Department of Biological Sciences, Northern Arizona University, 1899 S San Francisco St, Flagstaff, AZ, 86001, USA.,Department of Physiology, Institute of Biosciences, University of São Paulo, Trav. 14 da Rua do Matão, 321, São Paulo, SP, 05508-090, Brazil.,Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP, 14884-900, Brazil
| | - Danielle Dillon
- Department of Biological Sciences, Northern Arizona University, 1899 S San Francisco St, Flagstaff, AZ, 86001, USA
| | - Diego P Silva
- Smithsonian-Mason School of Conservation & George Mason University, 1500 Remount Rd, Front Royal, VA, 22630, USA
| | - Kathleen E Hunt
- Department of Biological Sciences, Northern Arizona University, 1899 S San Francisco St, Flagstaff, AZ, 86001, USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, 1899 S San Francisco St, Flagstaff, AZ, 86001, USA
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP, 14884-900, Brazil
| | - Fernando R Gomes
- Department of Physiology, Institute of Biosciences, University of São Paulo, Trav. 14 da Rua do Matão, 321, São Paulo, SP, 05508-090, Brazil
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7
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Xu S, Zhang S, Hu X, Zhang B, Yang S, Hu X, Liu S, Hu D, Bai J. Temporal and spatial dynamics of gastrointestinal parasite infection in Père David's deer. PeerJ 2021; 9:e11335. [PMID: 33996283 PMCID: PMC8106392 DOI: 10.7717/peerj.11335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 04/01/2021] [Indexed: 11/20/2022] Open
Abstract
Background The Père David's deer (Elaphurus davidianus) population was established from only a small number of individuals. Their genetic diversity is therefore relatively low and transmissible (parasitic) diseases affecting them merit further attention. Parasitic infections can affect the health, survival, and population development of the host. However, few reports have been published on the gastrointestinal parasites of Père David's deer. The aims of this study were: (1) to identify the intestinal parasites groups in Père David's deer; (2) to determine their prevalence and burden and clarify the effects of different seasons and regions on various indicators of Père David's deer intestinal parasites; (3) to evaluate the effects of the Père David's deer reproductive period on these parasites; (4) to reveal the regularity of the parasites in space and time. Methods In total, 1,345 Père David's deer faecal samples from four regions during four seasons were tested using the flotation (saturated sodium nitrate solution) to identify parasites of different genus or group, and the McMaster technique to count the number of eggs or oocysts. Results Four groups of gastrointestinal parasites were found, of which strongyles were dominant; their prevalence and burden were significantly higher than other groups. Significant temporal and spatial effects on gastrointestinal parasitic infection were found. Parasite diversity, prevalence, parasite burden, and aggregation were the highest in summer. Among the four regions, parasite diversity, prevalence, and burden were the highest in the Dongting Lake area. In addition, parasite diversity and burden during the reproductive period of Père David's deer was significantly higher than during the post-reproductive period. Conclusions The summer season and the reproductive period of Père David's deer had great potential for parasite transmission, and there is a high risk of parasite outbreaks in the Dongting Lake area.
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Affiliation(s)
- Shanghua Xu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Shumiao Zhang
- Department of Research, Beijing Milu Ecological Research Center, Beijing, China
| | - Xiaolong Hu
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Baofeng Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Shuang Yang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Xin Hu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | - Shuqiang Liu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Defu Hu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Jiade Bai
- Department of Research, Beijing Milu Ecological Research Center, Beijing, China
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8
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Zimmerman LM. The reptilian perspective on vertebrate immunity: 10 years of progress. J Exp Biol 2020; 223:223/21/jeb214171. [DOI: 10.1242/jeb.214171] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
ABSTRACT
Ten years ago, ‘Understanding the vertebrate immune system: insights from the reptilian perspective’ was published. At the time, our understanding of the reptilian immune system lagged behind that of birds, mammals, fish and amphibians. Since then, great progress has been made in elucidating the mechanisms of reptilian immunity. Here, I review recent discoveries associated with the recognition of pathogens, effector mechanisms and memory responses in reptiles. Moreover, I put forward key questions to drive the next 10 years of research, including how reptiles are able to balance robust innate mechanisms with avoiding self-damage, how B cells and antibodies are used in immune defense and whether innate mechanisms can display the hallmarks of memory. Finally, I briefly discuss the links between our mechanistic understanding of the reptilian immune system and the field of eco-immunology. Overall, the field of reptile immunology is poised to contribute greatly to our understanding of vertebrate immunity in the next 10 years.
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9
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Wang AZ, Husak JF. Endurance and sprint training affect immune function differently in green anole lizards ( Anolis carolinensis). J Exp Biol 2020; 223:jeb232132. [PMID: 32917817 DOI: 10.1242/jeb.232132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 01/08/2023]
Abstract
Limited resources must be partitioned among traits that enhance fitness. Although survival-related traits often trade off with reproduction, survival-related traits themselves may trade off with each other under energy limitations. Whole-organism performance and the immune system both enhance survival, yet are costly, but it is unclear how the two might trade off with each other under energy-limited conditions. Resources can be allocated to very different types of performance (e.g. aerobic endurance versus anaerobic sprinting), just as they can be allocated to different components of the immune system (e.g. innate versus acquired) to maximize survival. We forced allocation to different performance traits in green anole lizards (Anolis carolinensis) using specialized exercise training, to determine how different components of the immune system would be impacted by shifts in energy use. We measured immunocompetence in endurance-trained, sprint-trained and untrained control lizards by evaluating swelling response to phytohemagglutinin (cell-mediated immunity), antibody response to sheep red blood cells (acquired humoral immunity) and wound healing (integrated immunity). Endurance-trained lizards had reduced cell-mediated immunity, whereas sprint-trained lizards had reduced rates of wound healing. The acquired immune response was not affected by either type of training. Because each immune measure responded differently to the different types of training, our results do not support the hypothesis that simple energy limitation determines overall investment in immunity. Instead, different components of the immune system appear to be affected in ways specific to how energy is invested in performance.
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Affiliation(s)
- Andrew Z Wang
- Department of Biology, University of St Thomas, St. Paul, MN 55105, USA
| | - Jerry F Husak
- Department of Biology, University of St Thomas, St. Paul, MN 55105, USA
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10
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Zamora-Camacho FJ, Comas M, Moreno-Rueda G. Immune challenge does not impair short-distance escape speed in a newt. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Lind CM, Agugliaro J, Farrell TM. The metabolic response to an immune challenge in a viviparous snake, Sistrurus miliarius. J Exp Biol 2020; 223:jeb225185. [PMID: 32321747 DOI: 10.1242/jeb.225185] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/15/2020] [Indexed: 08/26/2023]
Abstract
Mounting an immune response may be energetically costly and require the diversion of resources away from other physiological processes. Yet, both the metabolic cost of immune responses and the factors that impact investment priorities remain poorly described in many vertebrate groups. For example, although viviparity has evolved many times in vertebrates, the relationship between immune function and pregnancy has been disproportionately studied in placental mammals. To examine the energetic costs of immune activation and the modulation of immune function during pregnancy in a non-mammalian vertebrate, we elicited an immune response in pregnant and non-pregnant pygmy rattlesnakes, Sistrurus miliarius, using lipopolysaccharide (LPS). Resting metabolic rate (RMR) was measured using flow-through respirometry. Immune function was examined using bactericidal assays and leukocyte counts. The RMR of pygmy rattlesnakes increased significantly in response to LPS injection. There was no statistically significant difference in the metabolic response of non-reproductive and pregnant snakes to LPS. Mean metabolic increments for pregnant females, non-reproductive females, and males were 13%, 18% and 26%, respectively. The ratio of heterophils to lymphocytes was elevated in response to LPS across reproductive categories; however, LPS did not impact plasma bactericidal ability in non-reproductive snakes. Although pregnant females had significantly higher plasma bactericidal ability compared with non-reproductive snakes prior to manipulation, their bactericidal ability declined in response to LPS. LPS administration also significantly reduced several litter characteristics, particularly when administrated relatively early in pregnancy. Our results indicate that immune performance is energetically costly and is altered during pregnancy, and that immune activation during pregnancy may result in tradeoffs that affect offspring in a viviparous reptile.
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Affiliation(s)
- Craig M Lind
- School of Natural Science and Mathematics, Stockton University, Galloway, NJ 08205, USA
| | - Joseph Agugliaro
- Department of Biological Sciences, Fairleigh Dickinson University, Madison, NJ 07940, USA
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12
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Wu Q, Richard M, Rutschmann A, Miles DB, Clobert J. Environmental variation mediates the prevalence and co-occurrence of parasites in the common lizard, Zootoca vivipara. BMC Ecol 2019; 19:44. [PMID: 31640667 PMCID: PMC6806499 DOI: 10.1186/s12898-019-0259-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 10/10/2019] [Indexed: 11/10/2022] Open
Abstract
Background Hosts and their parasites are under reciprocal selection, leading to coevolution. However, parasites depend not only on a host, but also on the host’s environment. In addition, a single host species is rarely infested by a single species of parasite and often supports multiple species (i.e., multi-infestation). Although the arms race between a parasite and its host has been well studied, few data are available on how environmental conditions may influence the process leading to multiple infestations. In this study, we examine whether: (1) environmental factors including altitude, temperature, vegetation cover, human disturbance, and grazing by livestock affect the prevalence of two types of ectoparasites, mites and ticks, on their host (the common lizard, Zootoca vivipara) and (2) competition is evident between mites and ticks. Results We found the probability of mite infestation increased with altitude and vegetation cover, but decreased with human disturbance and presence of livestock. In contrast, the probability of tick infestation was inversely associated with the same factors. Individuals with low body condition and males had higher mite loads. However, this pattern was not evident for tick loads. The results from a structural equation model revealed that mites and ticks indirectly and negatively affected each other’s infestation probability through an interaction involving the environmental context. We detected a direct negative association between mites and ticks only when considering estimates of parasite load. This suggests that both mites and ticks could attach to the same host, but once they start to accumulate, only one of them takes advantage. Conclusion The environment of hosts has a strong effect on infestation probabilities and parasite loads of mites and ticks. Autecological differences between mites and ticks, as indicated by their opposing patterns along environmental gradients, may explain the pattern of weak contemporary interspecific competition. Our findings emphasize the importance of including environmental factors and the natural history of each parasite species in studies of host–parasite coevolution.
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Affiliation(s)
- Qiang Wu
- CNRS, Station d'Ecologie Théorique et Expérimentale, UMR 5321 and Université Toulouse III-Paul Sabatier, 09200, Moulis, France.,Université Fédérale Toulouse Midi-Pyrénées, 31013, Toulouse, France
| | - Murielle Richard
- CNRS, Station d'Ecologie Théorique et Expérimentale, UMR 5321 and Université Toulouse III-Paul Sabatier, 09200, Moulis, France.
| | - Alexis Rutschmann
- CNRS, Station d'Ecologie Théorique et Expérimentale, UMR 5321 and Université Toulouse III-Paul Sabatier, 09200, Moulis, France.,Université Fédérale Toulouse Midi-Pyrénées, 31013, Toulouse, France.,School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Donald B Miles
- CNRS, Station d'Ecologie Théorique et Expérimentale, UMR 5321 and Université Toulouse III-Paul Sabatier, 09200, Moulis, France.,Department of Biological Sciences, Ohio University, 131 Life Sciences Building, Athens, OH, 45701, USA
| | - Jean Clobert
- CNRS, Station d'Ecologie Théorique et Expérimentale, UMR 5321 and Université Toulouse III-Paul Sabatier, 09200, Moulis, France
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13
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Leung TLF, Koprivnikar J. Your infections are what you eat: How host ecology shapes the helminth parasite communities of lizards. J Anim Ecol 2019; 88:416-426. [PMID: 30506672 DOI: 10.1111/1365-2656.12934] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/12/2018] [Indexed: 11/30/2022]
Abstract
Understanding how parasite communities are assembled, and the factors that influence their richness, can improve our knowledge of parasite-host interactions and help to predict the spread of infectious diseases. Previous comparative analyses have found significant influences of host ecology and life history, but focused on a few select host taxa. Host diet and habitat use play key roles in the acquisition of parasitic helminths as many are trophically transmitted, making these attributes potentially key indicators of infection risk. Given the paucity of comparative studies with non-piscine, non-avian or non-mammalian hosts, it is critical to examine the degree to which host ecology influences parasite communities in other host taxa in order to identify common drivers. We examined helminth diversity in over 350 species of lizards in relation to their body mass, ecology (diet and habitat use) and life history (clutch size, and ovo- or viviparity) using previously published data. Overall, lizard species with herbivorous diets harboured fewer types of helminths (especially larval stages), with similar results for traits that were ultimately strongly associated with diet (host mass and habitat use). Large hosts tended to be herbivores with few helminth types, whereas species utilizing arboreal habitats typically consumed some animal matter and hosted more helminths. Understanding how host ecology and life history are related to their parasite assemblages has significant implications for the risk of acquiring novel parasites. Our results indicate an overwhelming influence of host diet such that many helminths may be relatively easily acquired by hosts in new ranges, or through dietary shifts.
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Affiliation(s)
- Tommy L F Leung
- School of Environmental & Rural Sciences, University of New England, Armidale, NSW, Australia
| | - Janet Koprivnikar
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
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14
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Yap KN, Serota MW, Williams TD. The Physiology of Exercise in Free-Living Vertebrates: What Can We Learn from Current Model Systems? Integr Comp Biol 2018; 57:195-206. [PMID: 28662569 DOI: 10.1093/icb/icx016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
SYNOPSIS Many behaviors crucial for survival and reproductive success in free-living animals, including migration, foraging, and escaping from predators, involve elevated levels of physical activity. However, although there has been considerable interest in the physiological and biomechanical mechanisms that underpin individual variation in exercise performance, to date, much work on the physiology of exercise has been conducted in laboratory settings that are often quite removed from the animal's ecology. Here we review current, laboratory-based model systems for exercise (wind or swim tunnels for migration studies in birds and fishes, manipulation of exercise associated with non-migratory activity in birds, locomotion in lizards, and wheel running in rodents) to identify common physiological markers of individual variation in exercise capacity and/or costs of increased activity. Secondly, we consider how physiological responses to exercise might be influenced by (1) the nature of the activity (i.e., voluntary or involuntary, intensity, and duration), and (2) resource acquisition and food availability, in the context of routine activities in free-living animals. Finally, we consider evidence that the physiological effects of experimentally-elevated activity directly affect components of fitness such as reproduction and survival. We suggest that developing more ecologically realistic laboratory systems, incorporating resource-acquisition, functional studies across multiple physiological systems, and a life-history framework, with reproduction and survival end-points, will help reveal the mechanisms underlying the consequences of exercise, and will complement studies in free-living animals taking advantage of new developments in wildlife-tracking.
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Affiliation(s)
- Kang Nian Yap
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
| | - Mitchell W Serota
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British V5A 1S6, Canada, Columbia
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15
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Lailvaux SP, Husak JF. Predicting Life-History Trade-Offs with Whole-Organism Performance. Integr Comp Biol 2018; 57:325-332. [PMID: 28859417 DOI: 10.1093/icb/icx073] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
SYNOPSIS Whole-organism performance traits are key intermediaries between the organism and the environment. Because performance traits are energetically costly to both build and maintain, performance will compete with other life-history traits over a limited pool of acquired energetic resources at any given time, potentially leading to trade-offs in performance expression. Although these trade-offs can have important implications for organismal fitness we currently lack a conceptual framework for predicting both where trade-offs might be expected, and which traits may be especially prone to trade-offs with other fitness-related life-history traits. We propose such a framework based on an estimate of the energetic requirements of locomotion in vertebrates, the ecological cost of transport. By analyzing existing data on mammalian energetic budgets and life-history, we found that species with higher costs of locomotion also tended to be those with "slow" life histories that invest relatively less in current reproduction than "fast" life-history species. We discuss the potential implications of ectothermy for masking such relationships, and how this framework might be expanded upon in the future.
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Affiliation(s)
- Simon P Lailvaux
- Department of Biological Sciences, The University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148, USA
| | - Jerry F Husak
- Department of Biology, University of St. Thomas, 2115 Summit Avenue, St Paul, MN 55105, USA
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16
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Mészáros B, Herczeg G, Bajer K, Török J, Molnár O. Effects of energy and thermoregulation time on physiological state and sexual signal in a lizard. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 327:570-578. [PMID: 29377549 DOI: 10.1002/jez.2143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/26/2017] [Accepted: 01/06/2018] [Indexed: 12/12/2022]
Abstract
Theory of sexual selection states that males often develop showy signals, which reduce their survival but increase their reproductive success. During mate choice, these conspicuous signals can be honest indicators of individual quality conveying information about the signaler's physiological state. Sexually selected signals are influenced by many environmental factors; however, whether signals and physiological state are affected together is rarely studied. The ultraviolet-blue throat color of male Lacerta viridis is an intra- and intersexually selected signal connected to blood parasite infection and influenced by environmental factors. The aim of this study was to experimentally investigate how ecologically relevant environmental factors affect color signal intensity and key physiological traits parallel. During the mating season, we exposed 40 adult male lizards infected with blood parasites to food and basking time treatments in a full factorial design. We measured color, amount of reactive oxygen metabolites (ROMs), hematocrit, immunocompetence, and blood parasite intensity before and after treatments. High basking time resulted in elevated immunocompetence coupled with increased ROMs. The high food treatment increased nuptial color brightness, but also increased ROMs and decreased immunocompetence. In summary, our study provides experimental evidence about environmentally induced parallel changes in an honest sexual signal and several quality-indicator physiological traits. We showed that available energy and time for high metabolism have independent and sometimes opposite effects on individual state.
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Affiliation(s)
- Boglárka Mészáros
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Herczeg
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary
| | - Katalin Bajer
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary.,Laboratório de Biogeografia e Macroecologia, Universidade Federal do Rio Grande do Norte Centro de Biociências, Departamento de Botânica, Ecologia e Zoologia, Campus Universitário, Lagoa Nova, Natal-RN, Brazil
| | - János Török
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary
| | - Orsolya Molnár
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary.,Laboratório de Biogeografia e Macroecologia, Universidade Federal do Rio Grande do Norte Centro de Biociências, Departamento de Botânica, Ecologia e Zoologia, Campus Universitário, Lagoa Nova, Natal-RN, Brazil
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17
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Palacios MG, Bronikowski AM. Immune variation during pregnancy suggests immune component-specific costs of reproduction in a viviparous snake with disparate life-history strategies. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2017; 327:513-522. [PMID: 29356424 DOI: 10.1002/jez.2137] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/02/2017] [Accepted: 12/02/2017] [Indexed: 11/08/2022]
Abstract
Growing evidence suggests the existence of trade-offs between immune function and reproduction in diverse taxa. Among vertebrates, however, there is still a taxonomic bias toward studies in endotherms, particularly birds. We tested the hypothesis that reproduction entails immune-related costs in the viviparous garter snake, Thamnophis elegans, from populations that exhibit two life-history strategies, termed ecotypes, with contrasting paces of life. Between the two ecotypes, we predicted lower immune function in gravid than non-gravid females of both strategies, but with relatively larger immunity costs in the ecotype that generally invests more in current reproduction. Across individuals, we predicted greater immune costs for females investing more in the present specific reproductive event (i.e., higher fecundity) irrespective of their ecotype. We assessed leukocyte profiles and measured bactericidal capacity of plasma (innate immunity) and T- and B-lymphocyte proliferation (adaptive immunity) in gravid and non-gravid females in their natural habitats. We also collected data on reproductive output from these same gravid females brought into captivity. Gravid females of both ecotypes showed lower T-lymphocyte proliferation responses to concanavalin A than non-gravid females, but no differential costs were observed between ecotypes. The remaining immune variables did not vary between gravid and non-gravid females. Among gravid females within each ecotype, those with larger reproductive output showed lower total leukocyte counts, suggesting a fecundity-dependent trade-off. Our study contributes to the comparative ecoimmunology of vertebrates by highlighting the immune component-specificity of trade-offs between reproduction and immune function and showing that costs can be fecundity-dependent in some, but not all cases.
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Affiliation(s)
- Maria G Palacios
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa
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18
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Tylan C, Langkilde T. Local and systemic immune responses to different types of phytohemagglutinin in the green anole: Lessons for field ecoimmunologists. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2017; 327:322-332. [PMID: 29356446 DOI: 10.1002/jez.2108] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/13/2017] [Accepted: 08/21/2017] [Indexed: 01/15/2023]
Abstract
The phytohemagglutinin (PHA) skin test is commonly used by ecologists to assess cell-mediated immune function of wild animals. It can be performed quickly and easily in the field, involving injection of PHA and measurement of the resultant swelling. There are multiple formulations of PHA used in ecological studies, with potentially differing outcomes that could produce inconsistent results. We tested two common types of PHA in the green anole (Anolis carolinensis) to identify local and systemic immune responses underlying the resultant swelling at 6, 18, 24, and 48 hr post injection. There were differences in both local (injection site) and systemic (blood) leukocyte responses to PHA-L versus PHA-P. PHA-P injection produced a greater overall increase in local heterophil count at the injection site compared with PHA-L, and this response was greatest at 6 and 24 hr post injection. Systemically, heterophil percentage was higher in the blood of PHA-P- versus PHA-L-injected anoles at 24 hr post injection; the time point at which heterophil percentage peaked in PHA-P-injected anoles. These results indicate that although both PHA types are effective tests of immune function in green anoles, the PHA-P swelling response invokes a much stronger heterophilic response. PHA-L is a more specific test of lymphocyte function, particularly at 24 hr post injection, making it preferable for ecoimmunology studies.
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Affiliation(s)
- Catherine Tylan
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Tracy Langkilde
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.,Intercollege Graduate Degree Program in Ecology, The Center for Brain, Behavior and Cognition, The Pennsylvania State University, University Park, Pennsylvania, USA
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19
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Effects of Colour Morph and Temperature on Immunity in Males and Females of the Common Wall Lizard. Evol Biol 2017. [DOI: 10.1007/s11692-017-9422-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Landry Yuan F, Pickett EJ, Bonebrake TC. Cooler performance breadth in a viviparous skink relative to its oviparous congener. J Therm Biol 2016; 61:106-114. [DOI: 10.1016/j.jtherbio.2016.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 10/21/2022]
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21
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Sagonas K, Rota IA, Tsitsilonis OE, Pafilis P, Valakos ED. Infection risk dictates immunological divergence among populations in a Mediterranean lizard. J Evol Biol 2016; 29:1680-8. [PMID: 27208549 DOI: 10.1111/jeb.12903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/15/2016] [Accepted: 05/17/2016] [Indexed: 11/28/2022]
Abstract
The ability of vertebrates to evolve different defence strategies in response to varying parasitism regimes remains poorly understood. Hosts may adopt two different strategies to defend themselves against parasites: tolerance (hosts alleviate the negative fitness consequences of parasite infection) and resistance (hosts strengthen their immune response as parasite burden increases). Both strategies are effective, but fitness has been reported to decline faster in less-tolerant individuals. Here, we assessed the number of splenocytes and the cell-mediated response (proxies for resistance) and body condition (a proxy for tolerance) in four populations of a Greek endemic lizard (Podarcis gaigeae), each exposed to different infection risks (defined as the cumulative effect of parasite burden and duration of exposure). We anticipated that populations with heavy parasite burden would enhance the efficacy of their immune response (resistance) compared to lizards deriving from parasite-poor habitats. We also predicted that populations with longer exposure to parasites would be adopted and be more tolerant. Each factor (duration of exposure and parasite burden) had a distinct effect on the immune response, and thus, our results were rather complicated. Lizards with heavy parasite burden and aperiodic exposure demonstrated resistance, whereas lizards with heavy parasite burden and chronic exposure were more tolerant. Populations with low parasite burden and minimal exposure were more resistant. Our results suggest that the development of some immunological strategies may be differentiated under different infection risks, even within the same species.
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Affiliation(s)
- K Sagonas
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece.
| | - I A Rota
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - O E Tsitsilonis
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - P Pafilis
- Department of Zoology and Marine Biology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - E D Valakos
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
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22
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Sullivan K, Fairn E, Adamo SA. Sickness behaviour in the cricket Gryllus texensis: Comparison with animals across phyla. Behav Processes 2016; 128:134-43. [PMID: 27189926 DOI: 10.1016/j.beproc.2016.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/08/2016] [Accepted: 05/13/2016] [Indexed: 01/23/2023]
Abstract
Immune activation alters behaviour (i.e. sickness behaviour) in animals across phyla and is thought to aid recovery from infection. Hypotheses regarding the adaptive function of different sickness behaviours (e.g. decreased movement and appetite) include the energy conservation and predator avoidance hypotheses. These hypotheses were originally developed for mammals (e.g. Hart, 1988), however similar sickness behaviours are also observed in insects (e.g., crickets). We predicted that immune-challenged crickets (Gryllus texensis) would reduce feeding, grooming, and locomotion as well as increase shelter use, consistent with the energy conservation and predator avoidance hypotheses. We found evidence of illness-induced anorexia in adult and juvenile crickets, consistent with previous research (Adamo et al., 2010), but contrary to expectations, we found an increase in grooming, and no evidence that crickets decreased locomotion or increased shelter use in response to immune challenge. Therefore, our results do not support the energy conservation or predator avoidance hypotheses. The difference in sickness behaviour between insects and mammals is probably due, in part, to the lack of physiological fever in insects. We hypothesize that the lack of physiological fever reduces the need for energy conservation, decreasing the benefits of some sickness behaviours such as increased shelter use. These results, taken together with others in the literature, suggest that ectotherms and endotherms may differ significantly in the selective forces leading to the evolution of most sickness behaviours.
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Affiliation(s)
- Ken Sullivan
- Dept. Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Evan Fairn
- Dept. Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Shelley A Adamo
- Dept. Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada.
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23
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Husak JF, Ferguson HA, Lovern MB. Trade‐offs among locomotor performance, reproduction and immunity in lizards. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12653] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Jerry F. Husak
- Department of Biology University of St. Thomas St. Paul Minnesota 55105 USA
| | - Haley A. Ferguson
- Department of Biology University of St. Thomas St. Paul Minnesota 55105 USA
| | - Matthew B. Lovern
- Department of Integrative Biology Oklahoma State University Stillwater Oklahoma 74078 USA
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24
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Cox CL, Peaden RT, Cox RM. The metabolic cost of mounting an immune response in male brown anoles (Anolis sagrei). ACTA ACUST UNITED AC 2015; 323:689-695. [DOI: 10.1002/jez.1960] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 07/14/2015] [Accepted: 07/16/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Christian L. Cox
- Department of Biology; Georgia Southern University; Statesboro Georgia
- Department of Biology; University of Virginia; Charlottesville Virginia
| | - Robert T. Peaden
- Department of Biology; University of Virginia; Charlottesville Virginia
| | - Robert M. Cox
- Department of Biology; University of Virginia; Charlottesville Virginia
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25
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Mugabo M, Perret S, Decencière B, Meylan S, Le Galliard JF. Density-dependent immunity and parasitism risk in experimental populations of lizards naturally infested by ixodid ticks. Ecology 2015; 96:450-60. [PMID: 26240866 DOI: 10.1890/14-0524.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
When effective immune defenses against parasites are costly and resources limited, individuals are expected to alter their investment in immunity in response to the risk of infection. As an ecological factor that can affect both food abundance and parasite exposure, host density can play an important role in host immunity and host-parasite interactions. High levels of intraspecific competition for food and social stress at high host density may diminish immune defenses and increase host susceptibility to parasites. At the same time, for contagious and environmentally transmitted parasites, parasite exposure often increases with host density, whereas in mobile parasites that actively search for hosts, parasite exposure can decrease with host density due to the "encounter-dilution effect." To unravel these multiple and potentially opposing effects of host density on immunity, we manipulated density of the common lizard Zootoca vivipara and measured local inflammation in response to PHA injection and levels of infestation by the tick Ixodes ricinus, a mobile ectoparasite for which we expected an encounter-dilution effect to occur. Local inflammation strongly decreased with lizard density in adults, but not in yearlings. Tick infestation (abundance and prevalence) was negatively correlated with lizard density in both age classes. Using path analyses, we found independent, direct negative density feedbacks on immunity and parasite exposure in adults, supporting the hypothesis of energy constraints and/or physiological stress acting on immunity at high density. In contrast, for yearlings, the best path model showed that density diluted exposure to parasites, which themselves down-regulated immune defenses in lizards. These results highlight the importance of investigating the pathways among host density, host immunity, and parasite infestation, while accounting for relevant individual traits such as age.
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26
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Dupoué A, Stahlschmidt ZR, Michaud B, Lourdais O. Physiological state influences evaporative water loss and microclimate preference in the snake Vipera aspis. Physiol Behav 2015; 144:82-9. [DOI: 10.1016/j.physbeh.2015.02.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 02/09/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
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Lailvaux SP, Husak JF. The life history of whole-organism performance. QUARTERLY REVIEW OF BIOLOGY 2015; 89:285-318. [PMID: 25510077 DOI: 10.1086/678567] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
For almost 40 years, studies of whole-organism performance have formed a cornerstone of evolutionary physiology. Although its utility as a heuristic guide is beyond question, and we have learned much about morphological evolution from its application, the ecomorphological paradigm has frequently been applied to performance evolution in ways that range from unsatisfactory to inappropriate. More importantly, the standard ecomorphological paradigm does not account for tradeoffs among performance and other traits, nor between performance traits that are mediated by resource allocation. A revised paradigm that includes such tradeoffs, and the possible ways that performance and fitness-enhancing traits might affect each other, could potentially revivify the study of phenotypic evolution and make important inroads into understanding the relationships between morphology and performance and between performance and Darwinian fitness. We describe such a paradigm, and discuss the various ways that performance and key life-history traits might interact with and affect each other. We emphasize both the proximate mechanisms potentially linking such traits, and the likely ultimate factors driving those linkages, as well as the evolutionary implications for the overall, multivariate phenotype. Finally, we highlight several research directions that will shed light on the evolution and ecology of whole-organism performance and related life-history traits.
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28
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Zamora-Camacho FJ, Reguera S, Rubiño-Hispán MV, Moreno-Rueda G. Eliciting an immune response reduces sprint speed in a lizard. Behav Ecol 2014. [DOI: 10.1093/beheco/aru170] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Van Dyke JU, Brandley MC, Thompson MB. The evolution of viviparity: molecular and genomic data from squamate reptiles advance understanding of live birth in amniotes. Reproduction 2014; 147:R15-26. [DOI: 10.1530/rep-13-0309] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Squamate reptiles (lizards and snakes) are an ideal model system for testing hypotheses regarding the evolution of viviparity (live birth) in amniote vertebrates. Viviparity has evolved over 100 times in squamates, resulting in major changes in reproductive physiology. At a minimum, all viviparous squamates exhibit placentae formed by the appositions of maternal and embryonic tissues, which are homologous in origin with the tissues that form the placenta in therian mammals. These placentae facilitate adhesion of the conceptus to the uterus as well as exchange of oxygen, carbon dioxide, water, sodium, and calcium. However, most viviparous squamates continue to rely on yolk for nearly all of their organic nutrition. In contrast, some species, which rely on the placenta for at least a portion of organic nutrition, exhibit complex placental specializations associated with the transport of amino acids and fatty acids. Some viviparous squamates also exhibit reduced immunocompetence during pregnancy, which could be the result of immunosuppression to protect developing embryos. Recent molecular studies using both candidate-gene and next-generation sequencing approaches have suggested that at least some of the genes and gene families underlying these phenomena play similar roles in the uterus and placenta of viviparous mammals and squamates. Therefore, studies of the evolution of viviparity in squamates should inform hypotheses of the evolution of viviparity in all amniotes, including mammals.
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