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Quevarec L, Morran LT, Dufourcq-Sekatcheff E, Armant O, Adam-Guillermin C, Bonzom JM, Réale D. Host defense alteration in Caenorhabditis elegans after evolution under ionizing radiation. BMC Ecol Evol 2024; 24:95. [PMID: 38982371 PMCID: PMC11234525 DOI: 10.1186/s12862-024-02282-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 07/01/2024] [Indexed: 07/11/2024] Open
Abstract
BACKGROUND Adaptation to a stressor can lead to costs on other traits. These costs play an unavoidable role on fitness and influence the evolutionary trajectory of a population. Host defense seems highly subject to these costs, possibly because its maintenance is energetically costly but essential to the survival. When assessing the ecological risk related to pollution, it is therefore relevant to consider these costs to evaluate the evolutionary consequences of stressors on populations. However, to the best of our knowledge, the effects of evolution in irradiate environment on host defense have never been studied. Using an experimental evolution approach, we analyzed fitness across 20 transfers (about 20 generations) in Caenorhabditis elegans populations exposed to 0, 1.4, and 50.0 mGy.h- 1 of 137Cs gamma radiation. Then, populations from transfer 17 were placed in the same environmental conditions without irradiation (i.e., common garden) for about 10 generations before being exposed to the bacterial parasite Serratia marcescens and their survival was estimated to study host defense. Finally, we studied the presence of an evolutionary trade-off between fitness of irradiated populations and host defense. RESULTS We found a lower fitness in both irradiated treatments compared to the control ones, but fitness increased over time in the 50.0 mGy.h- 1, suggesting a local adaptation of the populations. Then, the survival rate of C. elegans to S. marcescens was lower for common garden populations that had previously evolved under both irradiation treatments, indicating that evolution in gamma-irradiated environment had a cost on host defense of C. elegans. Furthermore, we showed a trade-off between standardized fitness at the end of the multigenerational experiment and survival of C. elegans to S. marcescens in the control treatment, but a positive correlation between the two traits for the two irradiated treatments. These results indicate that among irradiated populations, those most sensitive to ionizing radiation are also the most susceptible to the pathogen. On the other hand, other irradiated populations appear to have evolved cross-resistance to both stress factors. CONCLUSIONS Our study shows that adaptation to an environmental stressor can be associated with an evolutionary cost when a new stressor appears, even several generations after the end of the first stressor. Among irradiated populations, we observed an evolution of resistance to ionizing radiation, which also appeared to provide an advantage against the pathogen. On the other hand, some of the irradiated populations seemed to accumulate sensitivities to stressors. This work provides a new argument to show the importance of considering evolutionary changes in ecotoxicology and for ecological risk assessment.
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Affiliation(s)
- Loïc Quevarec
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SERPEN/LECO, Cadarache, Saint Paul Lez Durance, 13115, France.
| | - Levi T Morran
- Department of Biology, Emory University, Atlanta, GA, 30322, USA
| | - Elizabeth Dufourcq-Sekatcheff
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SERPEN/LECO, Cadarache, Saint Paul Lez Durance, 13115, France
| | - Olivier Armant
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SERPEN/LECO, Cadarache, Saint Paul Lez Durance, 13115, France
| | - Christelle Adam-Guillermin
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS/LMDN, Cadarache, Saint Paul Lez Durance, 13115, France
| | - Jean-Marc Bonzom
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SERPEN/LECO, Cadarache, Saint Paul Lez Durance, 13115, France
| | - Denis Réale
- Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC, Canada
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2
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Taylor GT, McQueen A, Eastwood JR, Dupoué A, Wong BBM, Verhulst S, Peters A. No effect of testosterone or sexual ornamentation on telomere dynamics: A case study and meta-analyses. Ecol Evol 2024; 14:e11088. [PMID: 38435019 PMCID: PMC10905238 DOI: 10.1002/ece3.11088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/11/2024] [Accepted: 02/16/2024] [Indexed: 03/05/2024] Open
Abstract
Life-history theory predicts that reproductive investments are traded-off against self-maintenance. Telomeres, the protective caps on the ends of chromosomes, offer a promising avenue for assessing life-history trade-offs, as they shorten in response to stressors and are predictive of the remaining lifespan. In males, testosterone frequently mediates life-history trade-offs, in part, through its effects on sexual ornamentation, which is an important aspect of reproductive investment. However, studies of within-individual associations between telomere dynamics and sexual ornamentation are limited in number and have produced mixed results. Furthermore, most such studies have been observational, making it difficult to discern the nature of any causal relationship. To address this, we used short-acting testosterone implants in free-living male superb fairy-wrens (Malurus cyaneus) to stimulate the production of a sexual ornament: early moult into a costly blue breeding plumage. We found no evidence that elevated testosterone, and the consequent earlier moult into breeding plumage, accelerated telomere shortening. We therefore followed up with a systematic review and two meta-analyses (28 studies, 54 effect sizes) exploring the associations between telomeres and (1) testosterone and (2) sexual ornamentation. In line with our experimental findings, neither meta-analysis showed an overall correlation of testosterone or sexual ornamentation with telomere length or telomere dynamics. However, meta-regression showed that experimental, compared to observational, studies reported greater evidence of trade-offs. Our meta-analyses highlight the need for further experimental studies to better understand potential responses of telomere length or telomere dynamics to testosterone or sexual ornamentation.
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Affiliation(s)
- Gregory T. Taylor
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
| | - Alexandra McQueen
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
- Present address:
Centre for Integrative EcologyDeakin UniversityBurwoodVictoriaAustralia
| | | | - Andréaz Dupoué
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
- Present address:
CNRS Sorbonne Université, UMR 7618, iEES ParisUniversité Pierre et Marie CurieParisFrance
| | - Bob B. M. Wong
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Anne Peters
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
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3
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Encel SA, Simpson EK, Schaerf TM, Ward AJW. Immune challenge affects reproductive behaviour in the guppy ( Poecilia reticulata). ROYAL SOCIETY OPEN SCIENCE 2023; 10:230579. [PMID: 37564068 PMCID: PMC10410201 DOI: 10.1098/rsos.230579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/11/2023] [Indexed: 08/12/2023]
Abstract
Immunocompetence and reproduction are among the most important determinants of fitness. However, energetic and metabolic constraints create conflict between these two life-history traits. While many studies have explored the relationship between immune activity and reproductive fitness in birds and mammals inoculated with bacterial endotoxin, very few have focused on fish. Fish have been neglected in this area due, in part, to the claim that they are largely resistant to the immune effects of endotoxins. However, the present study suggests that they are susceptible to significant effects with respect to reproductive behaviour. Here, we examined the reproductive behaviour of male guppies following exposure to bacterial lipopolysaccharides (LPS) in comparison to that of male guppies in a control treatment. Additionally, we investigated the responses of females to these males. We show that although immune challenge does not suppress general activity in male guppies, it significantly reduces mating effort. While females showed no difference in general activity as a function of male treatments, they did exhibit reduced group cohesion in the presence of LPS-exposed males. We discuss this in the context of sickness behaviours, social avoidance of immune-challenged individuals and the effects of mounting an immune response on reproductive behaviour.
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Affiliation(s)
- Stella A. Encel
- School of Life and Environmental Sciences, University of Sydney, Camperdown 2006, Australia
| | - Emily K. Simpson
- School of Life and Environmental Sciences, University of Sydney, Camperdown 2006, Australia
| | - Timothy M. Schaerf
- School of Life and Environmental Sciences, University of Sydney, Camperdown 2006, Australia
| | - Ashley J. W. Ward
- School of Life and Environmental Sciences, University of Sydney, Camperdown 2006, Australia
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4
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Waffender A, Henshaw JM. Long-term persistence of exaggerated ornaments under Fisherian runaway despite costly mate search. J Evol Biol 2023; 36:45-56. [PMID: 36514848 DOI: 10.1111/jeb.14127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 10/31/2022] [Accepted: 11/14/2022] [Indexed: 12/15/2022]
Abstract
Exaggerated ornaments often evolve due to the mating preferences of the opposite sex. Genetic correlations between preferences and ornaments can lead both traits to elaborate dramatically in tandem, in a process known as 'Fisherian runaway'. However, in most previous models of Fisherian runaway, elaborate ornaments are not expected to persist when preferences are consistently costly to the choosing sex. In contrast, we show here that exaggerated male ornaments can be maintained long term even when females must pay a cost to choose their mates. Preferences per se are not costly in our model, but females can only act on their preferences by investing resources in mate search. We predict that mate search effort should decrease with the cost of sampling additional mates and increase with the number of possible ornaments that females can choose from. The potential for multiple exaggerated ornaments to coexist depends on subtleties of their cost structure: strict trade-offs (additive costs) favour sequential ornament evolution, whereas looser trade-offs (multiplicative costs) allow for coexistence. Lastly, we show that pleiotropy affecting both ornaments and preferences makes it difficult for Fisherian runaway to initiate, increasing the evolutionary time until ornamentation. Our model highlights the important but neglected role of mate search effort in sexual selection.
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Affiliation(s)
- Anna Waffender
- Institute of Biology I, University of Freiburg, Freiburg, Germany
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5
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Robustness in action: Leg loss does not affect mating success in male harvestmen. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03127-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Abstract
Defensive strategies, like other life-history traits favored by natural selection, may pose constraints on reproduction. A common anti-predator defense strategy that increases immediate survival is autotomy—the voluntary release of body parts. This type of morphological damage is considered to impose future costs for reproduction and fitness. We tested an alternative hypothesis that animals are robust (able to withstand and overcome perturbations) to this type of damage and do not experience any fitness costs in reproductive contexts. We explored the effects of experimental leg loss on the reproductive behavior of one species of Neotropical Prionostemma harvestmen. These arachnids undergo autotomy frequently, do not regenerate legs, and their courtship and mating necessitate the use of legs. We assessed the effect of losing different types of legs (locomotor or sensory) on courtship behavior and mating success in males. We found no differences in the mating success or in any measured aspect of reproductive behavior between eight-legged males and males that experienced loss of legs of any type. Additionally, we found that morphological traits related to body size did not predict mating success. Overall, our experimental findings support the null hypothesis that harvestmen are robust to the consequences of morphological damage and natural selection favors strategies that increase robustness.
Significance statement
In order to survive encounters with predators, animals have evolved many defensive strategies. Some of those behaviors, however, can come with a cost to their overall body condition. For example, some animals can voluntarily lose body parts (tails, legs, etc.) to escape. This process can then affect many aspects of an animal’s life, including reproduction. In a group of harvestmen (daddy long-legs) from Costa Rica, we tested the hypothesis that males are robust to the potential consequences of losing legs, and will not experience costs. We found that males that lost either legs used for locomotion or for sensory perception reproduced in the same way as animals with all of their legs. Consequently, we demonstrate that these arachnids are able to withstand the loss of legs with no effects on reproduction.
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6
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Powers MJ, Martz LD, Burton RS, Hill GE, Weaver RJ. Evidence for hybrid breakdown in production of red carotenoids in the marine invertebrate Tigriopus californicus. PLoS One 2021; 16:e0259371. [PMID: 34748608 PMCID: PMC8575244 DOI: 10.1371/journal.pone.0259371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 10/18/2021] [Indexed: 11/21/2022] Open
Abstract
The marine copepod, Tigriopus californicus, produces the red carotenoid pigment astaxanthin from yellow dietary precursors. This ‘bioconversion’ of yellow carotenoids to red is hypothesized to be linked to individual condition, possibly through shared metabolic pathways with mitochondrial oxidative phosphorylation. Experimental inter-population crosses of lab-reared T. californicus typically produces low-fitness hybrids is due in large part to the disruption of coadapted sets nuclear and mitochondrial genes within the parental populations. These hybrid incompatibilities can increase variability in life history traits and energy production among hybrid lines. Here, we tested if production of astaxanthin was compromised in hybrid copepods and if it was linked to mitochondrial metabolism and offspring development. We observed no clear mitonuclear dysfunction in hybrids fed a limited, carotenoid-deficient diet of nutritional yeast. However, when yellow carotenoids were restored to their diet, hybrid lines produced less astaxanthin than parental lines. We observed that lines fed a yeast diet produced less ATP and had slower offspring development compared to lines fed a more complete diet of algae, suggesting the yeast-only diet may have obscured effects of mitonuclear dysfunction. Astaxanthin production was not significantly associated with development among lines fed a yeast diet but was negatively related to development in early generation hybrids fed an algal diet. In lines fed yeast, astaxanthin was negatively related to ATP synthesis, but in lines fed algae, the relationship was reversed. Although the effects of the yeast diet may have obscured evidence of hybrid dysfunction, these results suggest that astaxanthin bioconversion may still be related to mitochondrial performance and reproductive success.
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Affiliation(s)
- Matthew J. Powers
- Department of Biological Sciences, Auburn University, Auburn, AL, United States of America
- * E-mail: (MJP); (LDM)
| | - Lucas D. Martz
- University of California, Scripps Institution of Oceanography, San Diego, CA, United States of America
- * E-mail: (MJP); (LDM)
| | - Ronald S. Burton
- University of California, Scripps Institution of Oceanography, San Diego, CA, United States of America
| | - Geoffrey E. Hill
- Department of Biological Sciences, Auburn University, Auburn, AL, United States of America
| | - Ryan J. Weaver
- Ecology, Evolution, and Organismal Biology Department, Iowa State University, Ames, IA, United States of America
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7
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LaDue CA, Schulte BA, Kiso WK, Freeman EW. Musth and sexual selection in elephants: a review of signalling properties and potential fitness consequences. BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Sexual selection mediated by multimodal signals is common among polygynous species, including seasonally breeding mammals. Indirect benefit models provide plausible explanations for how and why mate selection can occur in the absence of direct benefits. Musth — an asynchronous reproductive state in male elephants — facilitates both inter- and intrasexual selection via indirect benefits, and it is further communicated through a multimodal signal. In this review, we synthesise existing evidence that supports the hypothesis that musth is a multimodal signal subject to sexual selection and that male elephants increase their direct fitness by propagating this signal while females accrue indirect benefits. Musth is characterised by a suite of physiological and behavioural changes, serving to facilitate copulation between the sexes, and via multisensory modalities musth conveys honest information about the condition of a male. Female elephants mate preferentially with musth males, increasing their own fitness in the absence of direct benefits. In addition, musth resolves dynamic dominance hierarchies among male elephants and often eliminates the need for costly physical combat. Future work in this field should investigate potential postcopulatory selection mechanisms in elephants, including sperm competition and cryptic female choice. These topics join other fundamental questions related to sexual selection, signalling, and indirect benefits that are still unanswered in elephants.
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Affiliation(s)
- Chase A. LaDue
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
| | - Bruce A. Schulte
- Department of Biology, Western Kentucky University, Bowling Green, KY, USA
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8
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How healthy is your mate? Sex-specific consequences of parasite infections in the moth Helicoverpa armigera. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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9
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Maghsoudi A, Vaziri E, Feizabadi M, Mehri M. Fifty years of sheep red blood cells to monitor humoral immunity in poultry: a scientometric evaluation. Poult Sci 2020; 99:4758-4768. [PMID: 32988510 PMCID: PMC7598330 DOI: 10.1016/j.psj.2020.06.058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 05/12/2020] [Accepted: 06/19/2020] [Indexed: 11/27/2022] Open
Abstract
Sheep red blood cells (SRBC) are commonly employed by scientists to address humoral immune responses in poultry. While SRBC are closely related to the study of humoral immunity in poultry, the initial purpose of much research did not focus on the mechanisms involved. Here, we provide a qualitative approach and utilize scientometric techniques, including trend analyses, scientific collaborations and mapping, and word co-occurrence evaluations, to summarize the role of SRBC in the poultry studies. First, a search strategy on Web of Science (WoS) was conducted to find publications that included SRBC in the poultry studies. Publications were partitioned into 4 categories: nutrition, genetics, microbiology, and physiology. For scientometric evaluation, scientific maps and networks were produced to clarify the occurrence of SRBC in the poultry studies. Data used included 702 publications over a period of 50 y (1968-2018) that were retrieved from the WoS database. About 95% of the publications were published in English language. Indigenous, experimental, and commercial chickens, quail, and medicinal plants field/topics were the main subjects of publications. In recent years, authors have used SRBC to study humoral immune response as a secondary aim of their research, especially when poultry production/performance was studied. This was especially the case in recent decades for studies in poultry nutrition. Analysis of keywords co-occurrence showed that the phrase SRBC mostly occurred with chickens, immune response, and especially with broilers. Moreover, the “medicinal plants” are becoming important especially for research on broilers and the reduced use of antibiotics in feed. Consequently, in addition to studying the medicinal plants, finding antibiotic replacements, and/or growth performance in the birds, humoral immunity is suggested to be investigated using SRBC. Moreover, interdisciplinary studies with the cooperation of scientists from agriculture, veterinary, immunology, biochemistry and molecular biology, and toxicology will develop in the future.
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Affiliation(s)
- Ali Maghsoudi
- Department of Animal Science, Faculty of Agriculture, University of Zabol, Zabol, Iran; Department of Bioinformatics, University of Zabol, Zabol, Iran; Center of Agricultural Biotechnology, University of Zabol, Zabol, Iran.
| | - Esmaeil Vaziri
- Department of Information Science and Knowledge Studies, Faculty of Humanities, University of Zabol, Zabol, Iran
| | - Mansoureh Feizabadi
- Department of Information Science and Knowledge Studies, School of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Mehran Mehri
- Department of Animal Science, Faculty of Agriculture, University of Zabol, Zabol, Iran
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10
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Orton RW, Kinsey CT, McBrayer LD. Mite load predicts the quality of sexual color and locomotor performance in a sexually dichromatic lizard. Ecol Evol 2020; 10:3152-3163. [PMID: 32273977 PMCID: PMC7141043 DOI: 10.1002/ece3.5689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 01/05/2023] Open
Abstract
Since Darwin, the maintenance of bright sexual colors has recurrently been linked to mate preference. However, the mechanisms underpinning such preferences for bright colors would not be resolved for another century. Likely, the idea of selection for colors that could decrease the chances of survival (e.g., flashy colors that can inadvertently attract predators) was perceived as counterintuitive. It is now widely accepted that these extreme colors often communicate to mates the ability to survive despite a "handicap" and act as honest signals of individual quality when they are correlated with the quality of other traits that are directly linked to individual fitness. Sexual colors in males are frequently perceived as indicators of infection resistance, in particular. Still, there remains considerable discord among studies attempting to parse the relationships between the variables associating sexual color and infection resistance, such as habitat type and body size. This discord may arise from complex interactions between these variables. Here, we ask if sexual color in male Florida scrub lizards (Sceloporus woodi) is an honest signal of resistance to chigger mite infection. To this end, we use linear modeling to explore relationships between mite load, different components of sexual color, ecological performance, body size, and habitat type. Our data show that that the brightness of sexual color in scrub lizards is negatively associated with the interaction between mite load and body size, and scrub lizards suffer decreased endurance capacity with increases in mite load. Our data also indicate that mite load, performance, and sexual color in male scrub lizards can vary between habitat types. Collectively, these results suggest that sexual color in scrub lizards is an honest indicator of individual quality and further underscore the importance of considering multiple factors when testing hypotheses related to the maintenance of sexual color.
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Affiliation(s)
- Richard W. Orton
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTXUSA
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11
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Lelono A, Robledo-Ruiz DA, Berghof TVL, Parmentier HK, Riedstra B, Groothuis TG. Does paternal immunocompetence affect offspring vulnerability to maternal androgens? A study in domestic chickens. Biol Open 2019; 8:bio.045096. [PMID: 31748241 PMCID: PMC6899007 DOI: 10.1242/bio.045096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Exposure of yolk androgens can positively stimulate chick growth and competitive ability, but may negatively affect immunity. It has been hypothesized that only chicks from immunologically superior fathers can bear the cost of prenatal exposure to high androgen levels. To test this hypothesis, we paired roosters from two selection lines, one up- and one down-selected for natural antibodies (NAbs), with hens from a control line. We measured yolk testosterone and androstenedione levels, and we injected the treatment group of eggs of each female with testosterone suspended in sesame oil and the control group with sesame oil only. We then measured hatching success and growth, and characterized the humoral and cellular immune responses using three different challenges: a phyto-hemagglutinin, a lipopolysaccharide and a sheep red blood cell challenge. We found that the hatching success, body mass, initial levels of natural antibodies and the chicks’ immunological responses to the three different challenges and development were affected neither by paternal immunocompetence nor by treatment. These results do not support the hypothesis that chicks from low-NAb line fathers are more sensitive to testosterone exposure during embryonic development than chicks from high-NAb line fathers. Summary: Our study shows that there were no effects of paternal natural antibody line, increased embryonic testosterone exposure or the interaction of both on immunocompetence of chicks.
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Affiliation(s)
- Asmoro Lelono
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands .,Department of Biology, Faculty of Mathematics and Natural Sciences, University of Jember, 68121 Jember, East Java, The Republic of Indonesia
| | - Diana A Robledo-Ruiz
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Tom V L Berghof
- Department of Animal Sciences, Wageningen University & Research Animal Breeding and Genomics, P.O. Box 338, 6700 AH Wageningen, The Netherlands
| | - Henk K Parmentier
- Department of Animal Sciences, Wageningen University & Research Adaptation Physiology, P.O. Box 338, 6700 AH Wageningen, The Netherlands
| | - Bernd Riedstra
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Ton G Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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12
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Carleial R, McDonald GC, Pizzari T. Dynamic phenotypic correlates of social status and mating effort in male and female red junglefowl, Gallus gallus. J Evol Biol 2019; 33:22-40. [PMID: 31529557 PMCID: PMC6972591 DOI: 10.1111/jeb.13541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 11/30/2022]
Abstract
Despite widespread evidence that mating and intrasexual competition are costly, relatively little is known about how these costs dynamically change male and female phenotypes. Here, we test multiple hypotheses addressing this question in replicate flocks of red junglefowl (Gallus gallus). First, we test the interrelationships between social status, comb size (a fleshy ornament) and body mass at the onset of a mating trial. While comb size covaried positively with body mass across individuals of both sexes, comb size was positively related to social status in females but not in males. Second, we test for changes within individuals in body mass and comb size throughout the mating trial. Both body mass and comb size declined at the end of a trial in both sexes, suggesting that mating effort and exposure to the opposite sex are generally costly. Males lost more body mass if they (a) were socially subordinate, (b) were chased by other males or (c) mated frequently, indicating that subordinate status and mating are independently costly. Conversely, females lost more body mass if they were exposed to a higher frequency of coerced matings, suggesting costs associated with male sexual harassment and female resistance, although costs of mating per se could not be completely ruled out. Neither competitive nor mating interactions predicted comb size change in either sex. Collectively, these results support the notion that sex‐specific costs associated with social status and mating effort result in differential, sex‐specific dynamics of phenotypic change.
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Affiliation(s)
- Rômulo Carleial
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK
| | - Grant C McDonald
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK.,Department of Ecology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Tommaso Pizzari
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK
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13
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Prokop P. Male preferences for nuptial gifts and gift weight loss amongst the nursery web spider, Pisaura mirabilis. J ETHOL 2019. [DOI: 10.1007/s10164-019-00612-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Pizzari T, McDonald GC. Sexual selection in socially-structured, polyandrous populations: Some insights from the fowl. ADVANCES IN THE STUDY OF BEHAVIOR 2019. [DOI: 10.1016/bs.asb.2019.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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15
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Penley MJ, Greenberg AB, Khalid A, Namburar SR, Morran LT. No measurable fitness cost to experimentally evolved host defence in the Caenorhabditis elegans-Serratia marcescens
host-parasite system. J Evol Biol 2018; 31:1976-1981. [DOI: 10.1111/jeb.13372] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/27/2018] [Accepted: 08/24/2018] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Arooj Khalid
- Department of Biology; Emory University; Atlanta GA USA
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16
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Loggie JW, Garner SR, Partridge CG, Dixon B, Knapp R, Neff BD. A test of the effects of androgens on immunity: No relationship between 11-ketotestosterone and immune performance in bluegill (Lepomis macrochirus). Gen Comp Endocrinol 2018; 261:1-8. [PMID: 29355535 DOI: 10.1016/j.ygcen.2018.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 01/13/2018] [Accepted: 01/13/2018] [Indexed: 11/24/2022]
Abstract
The immunosuppressive effects of androgens are a key component of the immunocompetence handicap hypothesis (ICHH). Here, we use bluegill sunfish (Lepomis macrochirus) to test two predictions arising from this hypothesis: (1) natural circulating concentrations of the androgen 11-ketotestosterone (11-KT) will be negatively related with measures of immunity, and (2) immune stimulation will lower circulating 11-KT concentration. We found no evidence for a relationship between natural circulating 11-KT concentration and measures of immunity (lymphocyte and granulocyte counts, respiratory burst, cytokine mRNA levels), and an immune stimulation with Vibrio vaccine did not affect circulating 11-KT concentration. We also performed a meta-analysis of immune stimulation studies to help interpret our results, and report evidence suggesting that immune stimulation has weaker effects on androgen levels in fishes compared to other vertebrates. These results suggest that the ICHH may not apply to all vertebrates, although it remains premature to state what factors account for the weaker evidence in fishes that androgens are immunosuppressive.
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Affiliation(s)
- John W Loggie
- Department of Biology, The University of Western Ontario, 1151 Richmond St., London, ON N6A 5B7, Canada
| | - Shawn R Garner
- Department of Biology, The University of Western Ontario, 1151 Richmond St., London, ON N6A 5B7, Canada
| | - Charlyn G Partridge
- Annis Water Resources Institute, Grand Valley State University, 740 W. Shoreline Dr., Muskegon, MI 49441, USA
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1, Canada
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
| | - Bryan D Neff
- Department of Biology, The University of Western Ontario, 1151 Richmond St., London, ON N6A 5B7, Canada.
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17
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Weaver RJ, Koch RE, Hill GE. What maintains signal honesty in animal colour displays used in mate choice? Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0343. [PMID: 28533460 DOI: 10.1098/rstb.2016.0343] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2017] [Indexed: 12/15/2022] Open
Abstract
Many of the colour displays of animals are proposed to have evolved in response to female mate choice for honest signals of quality, but such honest signalling requires mechanisms to prevent cheating. The most widely accepted and cited mechanisms for ensuring signal honesty are based on the costly signalling hypothesis, which posits that costs associated with ornamentation prevent low-quality males from being highly ornamented. Alternatively, by the index hypothesis, honesty can be achieved via cost-free mechanisms if ornament production is causally linked to core physiological pathways. In this essay, we review how a costly signalling framework has shaped empirical research in mate choice for colourful male ornaments and emphasize that alternative interpretations are plausible under an index signalling framework. We discuss the challenges in both empirically testing and distinguishing between the two hypotheses, noting that they need not be mutually exclusive. Finally, we advocate for a comprehensive approach to studies of colour signals that includes the explicit consideration of cost-free mechanisms for honesty.This article is part of the themed issue 'Animal coloration: production, perception, function and application'.
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Affiliation(s)
- Ryan J Weaver
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Rebecca E Koch
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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18
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Lewnard JA, Townsend JP. Climatic and evolutionary drivers of phase shifts in the plague epidemics of colonial India. Proc Natl Acad Sci U S A 2016; 113:14601-14608. [PMID: 27791071 PMCID: PMC5187705 DOI: 10.1073/pnas.1604985113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Immune heterogeneity in wild host populations indicates that disease-mediated selection is common in nature. However, the underlying dynamic feedbacks involving the ecology of disease transmission, evolutionary processes, and their interaction with environmental drivers have proven challenging to characterize. Plague presents an optimal system for interrogating such couplings: Yersinia pestis transmission exerts intense selective pressure driving the local persistence of disease resistance among its wildlife hosts in endemic areas. Investigations undertaken in colonial India after the introduction of plague in 1896 suggest that, only a decade after plague arrived, a heritable, plague-resistant phenotype had become prevalent among commensal rats of cities undergoing severe plague epidemics. To understand the possible evolutionary basis of these observations, we developed a mathematical model coupling environmentally forced plague dynamics with evolutionary selection of rats, capitalizing on extensive archival data from Indian Plague Commission investigations. Incorporating increased plague resistance among rats as a consequence of intense natural selection permits the model to reproduce observed changes in seasonal epidemic patterns in several cities and capture experimentally observed associations between climate and flea population dynamics in India. Our model results substantiate Victorian era claims of host evolution based on experimental observations of plague resistance and reveal the buffering effect of such evolution against environmental drivers of transmission. Our analysis shows that historical datasets can yield powerful insights into the transmission dynamics of reemerging disease agents with which we have limited contemporary experience to guide quantitative modeling and inference.
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Affiliation(s)
- Joseph A Lewnard
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520
| | - Jeffrey P Townsend
- Department of Biostatistics, Yale School of Public Health, New Haven, CT 06510;
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520
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19
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Gethings O, Sage R, Morgan E, Leather S. Body condition is negatively associated with infection with Syngamus trachea in the ring-necked pheasant (Phasianus colchicus). Vet Parasitol 2016; 228:1-5. [DOI: 10.1016/j.vetpar.2016.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/29/2016] [Accepted: 08/04/2016] [Indexed: 11/17/2022]
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20
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Koch RE, Josefson CC, Hill GE. Mitochondrial function, ornamentation, and immunocompetence. Biol Rev Camb Philos Soc 2016; 92:1459-1474. [DOI: 10.1111/brv.12291] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 06/11/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Rebecca E. Koch
- Department of Biological Sciences; Auburn University; Auburn AL 36849 U.S.A
| | - Chloe C. Josefson
- Department of Biological Sciences; Auburn University; Auburn AL 36849 U.S.A
| | - Geoffrey E. Hill
- Department of Biological Sciences; Auburn University; Auburn AL 36849 U.S.A
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21
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Viblanc VA, Dobson FS, Stier A, Schull Q, Saraux C, Gineste B, Pardonnet S, Kauffmann M, Robin JP, Bize P. Mutually honest? Physiological ‘qualities’ signalled by colour ornaments in monomorphic king penguins. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12729] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Vincent A. Viblanc
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
- Centre d'Ecologie Fonctionnelle et Evolutive; Equipe Ecologie Comportementale; UMR 5175 CNRS; 1919 route de Mende Montpellier 34293 France
| | - F. Stephen Dobson
- Centre d'Ecologie Fonctionnelle et Evolutive; Equipe Ecologie Comportementale; UMR 5175 CNRS; 1919 route de Mende Montpellier 34293 France
- Department of Biological Sciences; Auburn University; 311 Funchess Hall Auburn AL 36849 USA
| | - Antoine Stier
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Quentin Schull
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Claire Saraux
- IFREMER; UMR MARBEC; Avenue Jean Monnet BP 171 Sète Cedex 34203 France
| | - Benoit Gineste
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Sylvia Pardonnet
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Marion Kauffmann
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Jean-Patrice Robin
- Université de Strasbourg; IPHC; 23 rue Becquerel Strasbourg 67087 France
- CNRS; UMR 7178; Strasbourg 67087 France
| | - Pierre Bize
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
- Institute of Biological and Environmental Sciences; University of Aberdeen; Scotland UK
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McDonald JL, Smith GC, McDonald RA, Delahay RJ, Hodgson D. Mortality trajectory analysis reveals the drivers of sex-specific epidemiology in natural wildlife-disease interactions. Proc Biol Sci 2015; 281:rspb.2014.0526. [PMID: 25056621 PMCID: PMC4123697 DOI: 10.1098/rspb.2014.0526] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
In animal populations, males are commonly more susceptible to disease-induced mortality than females. However, three competing mechanisms can cause this sex bias: weak males may simultaneously be more prone to exposure to infection and mortality; being ‘male’ may be an imperfect proxy for the underlying driver of disease-induced mortality; or males may experience increased severity of disease-induced effects compared with females. Here, we infer the drivers of sex-specific epidemiology by decomposing fixed mortality rates into mortality trajectories and comparing their parameters. We applied Bayesian survival trajectory analysis to a 22-year longitudinal study of a population of badgers (Meles meles) naturally infected with bovine tuberculosis (bTB). At the point of infection, infected male and female badgers had equal mortality risk, refuting the hypothesis that acquisition of infection occurs in males with coincidentally high mortality. Males and females exhibited similar levels of heterogeneity in mortality risk, refuting the hypothesis that maleness is only a proxy for disease susceptibility. Instead, sex differences were caused by a more rapid increase in male mortality rates following infection. Males are indeed more susceptible to bTB, probably due to immunological differences between the sexes. We recommend this mortality trajectory approach for the study of infection in animal populations.
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Affiliation(s)
- Jennifer L McDonald
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9EZ, UK
| | - Graham C Smith
- National Wildlife Management Centre, Animal Health and Veterinary Laboratories Agency, Sand Hutton, York YO41 1LZ, UK
| | - Robbie A McDonald
- Environment and Sustainability Institute, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall TR10 9EZ, UK
| | - Richard J Delahay
- National Wildlife Management Centre, Animal Health and Veterinary Laboratories Agency, Sand Hutton, York YO41 1LZ, UK
| | - Dave Hodgson
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9EZ, UK
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23
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Khan I, Prakash A, Agashe D. Immunosenescence and the ability to survive bacterial infection in the red flour beetle Tribolium castaneum. J Anim Ecol 2015; 85:291-301. [DOI: 10.1111/1365-2656.12433] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/14/2015] [Indexed: 12/01/2022]
Affiliation(s)
- Imroze Khan
- National Centre for Biological Sciences; Tata Institute of Fundamental Research; Bangalore India
| | - Arun Prakash
- National Centre for Biological Sciences; Tata Institute of Fundamental Research; Bangalore India
| | - Deepa Agashe
- National Centre for Biological Sciences; Tata Institute of Fundamental Research; Bangalore India
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24
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Smyth KN, Drea CM. Patterns of parasitism in the cooperatively breeding meerkat: a cost of dominance for females. Behav Ecol 2015. [DOI: 10.1093/beheco/arv132] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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25
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Muriel J, Salmón P, Nunez-Buiza A, de Salas F, Pérez-Rodríguez L, Puerta M, Gil D. Context-dependent effects of yolk androgens on nestling growth and immune function in a multibrooded passerine. J Evol Biol 2015; 28:1476-88. [PMID: 26079258 DOI: 10.1111/jeb.12668] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/08/2015] [Indexed: 01/08/2023]
Abstract
Female birds may adjust their offspring phenotype to the specific requirements of the environment by differential allocation of physiologically active substances into yolks, such as androgens. Yolk androgens have been shown to accelerate embryonic development, growth rate and competitive ability of nestlings, but they can also entail immunological costs. The balance between costs and benefits of androgen allocation is expected to depend on nestling environment. We tested this hypothesis in a multibrooded passerine, the spotless starling, Sturnus unicolor. We experimentally manipulated yolk androgen levels using a between-brood design and evaluated its effects on nestling development, survival and immune function. Both in first and replacement broods, the embryonic development period was shorter for androgen-treated chicks than controls, but there were no differences in second broods. In replacement broods, androgen-treated chicks were heavier and larger than those hatched from control eggs, but this effect was not observed in the other breeding attempts. Androgen exposure reduced survival with respect to controls only in second broods. Regarding immune function, we detected nonsignificant trends for androgen treatment to activate two important components of innate and adaptive immunity (IL-6 and Ig-A levels, respectively). Similarly, androgen-treated chicks showed greater lymphocyte proliferation than controls in the first brood and an opposite trend in the second brood. Our results indicate that yolk androgen effects on nestling development and immunity depend on the environmental conditions of each breeding attempt. Variation in maternal androgen allocation to eggs could be explained as the result of context-dependent optimal strategies to maximize offspring fitness.
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Affiliation(s)
- J Muriel
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| | - P Salmón
- Department of Biology, Evolutionary Ecology Unit, Lund University, Lund, Sweden
| | - A Nunez-Buiza
- Departamento de Fisiología Animal II, Facultad de Ciencias Biológicas, Universidad Complutense, Madrid, Spain
| | - F de Salas
- Departamento de Fisiología Animal II, Facultad de Ciencias Biológicas, Universidad Complutense, Madrid, Spain
| | - L Pérez-Rodríguez
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain.,Departamento de Ecología Evolutiva, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| | - M Puerta
- Departamento de Fisiología Animal II, Facultad de Ciencias Biológicas, Universidad Complutense, Madrid, Spain
| | - D Gil
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
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26
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Ortega J, Pellitteri-Rosa D, López P, Martín J. Dorsal pattern polymorphism in female Iberian wall lizards: differences in morphology, dorsal coloration, immune response, and reproductive investment. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12599] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jesús Ortega
- Departamento de Ecología Evolutiva; C.S.I.C.; Museo Nacional de Ciencias Naturales; José Gutiérrez Abascal 2 E-28006 Madrid Spain
| | - Daniele Pellitteri-Rosa
- Dipartimento di Scienze della Terra e dell'Ambiente; DSTA; Università di Pavia; Via Ferrata 9 27100 Pavia Italy
| | - Pilar López
- Departamento de Ecología Evolutiva; C.S.I.C.; Museo Nacional de Ciencias Naturales; José Gutiérrez Abascal 2 E-28006 Madrid Spain
| | - José Martín
- Departamento de Ecología Evolutiva; C.S.I.C.; Museo Nacional de Ciencias Naturales; José Gutiérrez Abascal 2 E-28006 Madrid Spain
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27
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Meaden S, Paszkiewicz K, Koskella B. The cost of phage resistance in a plant pathogenic bacterium is context-dependent. Evolution 2015; 69:1321-8. [PMID: 25809535 PMCID: PMC4979666 DOI: 10.1111/evo.12652] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 03/17/2015] [Indexed: 12/24/2022]
Abstract
Parasites are ubiquitous features of living systems and many parasites severely reduce the fecundity or longevity of their hosts. This parasite-imposed selection on host populations should strongly favor the evolution of host resistance, but hosts typically face a trade-off between investment in reproductive fitness and investment in defense against parasites. The magnitude of such a trade-off is likely to be context-dependent, and accordingly costs that are key in shaping evolution in nature may not be easily observable in an artificial environment. We set out to assess the costs of phage resistance for a plant pathogenic bacterium in its natural plant host versus in a nutrient-rich, artificial medium. We demonstrate that mutants of Pseudomonas syringae that have evolved resistance via a single mutational step pay a substantial cost for this resistance when grown on their tomato plant hosts, but do not realize any measurable growth rate costs in nutrient-rich media. This work demonstrates that resistance to phage can significantly alter bacterial growth within plant hosts, and therefore that phage-mediated selection in nature is likely to be an important component of bacterial pathogenicity.
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Affiliation(s)
- Sean Meaden
- College of Life and Environmental Sciences, University of Exeter, Penryn Campus, TR10 9FE, United Kingdom.
| | - Konrad Paszkiewicz
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Britt Koskella
- College of Life and Environmental Sciences, University of Exeter, Penryn Campus, TR10 9FE, United Kingdom
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28
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Tu Y, Siegel PB. Asymmetries in chickens from lines selected and relaxed for high or low antibody titers to sheep red blood cells. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2015; 28:323-7. [PMID: 25656213 PMCID: PMC4341075 DOI: 10.5713/ajas.14.0410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/14/2014] [Accepted: 09/04/2014] [Indexed: 11/27/2022]
Abstract
Wattle length, width, and area were measured to classify bilateral asymmetries in four lines of chickens. The lines were the S26 generation of White Leghorns selected for high (HAS) or low (LAS) response to sheep red blood cells and sublines in which selection had been relaxed for three generations (high antibody relaxed [HAR] and low antibody relaxed [LAR]). Antibody titers (AB) were greater for HAS than for HAR with both greater than for LAS and LAR which while different for males did not differ for females. The low antibody lines were heavier and reached sexual maturity at younger age than the high antibody lines. In general, wattle length, width, and area were greater in the low than high antibody lines. In 24 comparisons for bilaterality 18 exhibited fluctuating asymmetry and 6 exhibited directional asymmetry with 5 of the 6 being for wattle length. There was not a clear pattern for changes in degree of asymmetry when selection was relaxed for 3 generations. For females, the relative asymmetry (RA) of wattle area was larger (p≤0.05) for HAR than for LAR and not different from the selected lines and relaxed lines. There were no differences among lines for RA of wattle length and width of females and wattle length, width, and area of males.
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Affiliation(s)
- Yunjie Tu
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - P B Siegel
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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29
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Alvarez TA, Gray PB. Effects of Acute Change in Health Status on Human Female Sexuality. ACTA ACUST UNITED AC 2015. [DOI: 10.4303/jem/235850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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30
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Simons MJP, Maia R, Leenknegt B, Verhulst S. Carotenoid-dependent signals and the evolution of plasma carotenoid levels in birds. Am Nat 2014; 184:741-51. [PMID: 25438174 DOI: 10.1086/678402] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Sexual selection has resulted in a wide array of ornaments used in mate choice, and such indicator traits signal quality honestly when they bear costs, precluding cheating. Carotenoid-dependent coloration has attracted considerable attention in this context, because investing carotenoids in coloration has to be traded off against its physiological functions; carotenoids are antioxidants and increase immunocompetence. This trade-off is hypothesized to underlie the honesty of carotenoid-dependent coloration, signaling the "handicap" of allocating carotenoids away from somatic maintenance toward sexual display. Utilizing recent advances in modeling adaptive evolution, we used a comparative approach to investigate the evolution of plasma carotenoid levels using a species-level phylogeny of 178 bird species. We find that the evolutionary optimum for carotenoid levels is higher in lineages that evolved carotenoid-dependent coloration, with strong attraction toward this optimum. Hence, carotenoids do not appear to be limiting, given that higher carotenoid levels readily evolve in response to the evolution of carotenoid-dependent coloration. These findings challenge the assumption that carotenoids are a scarce resource and thus also challenge the hypothesis that physiological resource value of carotenoids underlies honesty of carotenoid-dependent traits. Therefore, the comparative evidence suggests that other factors, such as the acquisition and incorporation of carotenoids, are involved in maintaining signal honesty.
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Affiliation(s)
- Mirre J P Simons
- Behavioural Biology, Centre for Life Sciences, University of Groningen, PO Box 11103, 9700CC, Groningen, The Netherlands
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31
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A test of the effect of testosterone on a sexually selected carotenoid trait in a cardueline finch. Ecol Res 2014. [DOI: 10.1007/s11284-014-1201-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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32
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Tomlinson AJ, Chambers MA, Wilson GJ, McDonald RA, Delahay RJ. Sex-related heterogeneity in the life-history correlates of Mycobacterium bovis infection in European badgers (Meles meles). Transbound Emerg Dis 2014; 60 Suppl 1:37-45. [PMID: 24171847 DOI: 10.1111/tbed.12097] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 11/28/2022]
Abstract
Heterogeneity in the progression of disease amongst individual wild animals may impact on both pathogen and host dynamics at the population level, through differential effects on transmission, mortality and reproductive output. The role of the European badger (Meles meles) as a reservoir host for Mycobacterium bovis infection in the UK and Ireland has been the focus of intense research for many years. Here, we investigate life-history correlates of infection in a high-density undisturbed badger population naturally infected with M. bovis. We found no evidence of a significant impact of M. bovis infection on female reproductive activity or success, with evidence of reproduction continuing successfully for several years in the face of M. bovis excretion. We also found evidence to support the hypothesis that female badgers are more resilient to established M. bovis infection than male badgers, with longer survival times following the detection of bacterial excretion. We discuss the importance of infectious breeding females in the persistence of M. bovis in badger populations, and how our findings in male badgers are consistent with testosterone-induced immunosuppression. In addition, we found significant weight loss in badgers with evidence of disseminated infection, based on the culture of M. bovis from body systems other than the respiratory tract. For females, there was a gradual loss of weight as infection progressed, whereas males only experienced substantial weight loss when infection had progressed to the point of dissemination. We discuss how these differences may be explained in terms of resource allocation and physiological trade-offs.
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Brock PM, Murdock CC, Martin LB. The history of ecoimmunology and its integration with disease ecology. Integr Comp Biol 2014; 54:353-62. [PMID: 24838746 DOI: 10.1093/icb/icu046] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ecoimmunology is an example of how fruitful integrative approaches to biology can be. Since its emergence, ecoimmunology has sparked constructive debate on a wide range of topics, from the molecular mechanics of immune responses to the role of immunity in shaping the evolution of life histories. To complement the symposium Methods and Mechanisms in Ecoimmunology and commemorate the inception of the Division of Ecoimmunology and Disease Ecology within the Society for Integrative and Comparative Biology, we appraise the origins of ecoimmunology, with a focus on its continuing and valuable integration with disease ecology. Arguably, the greatest contribution of ecoimmunology to wider biology has been the establishment of immunity as an integral part of organismal biology, one that may be regulated to maximize fitness in the context of costs, constraints, and complex interactions. We discuss historical impediments and ongoing progress in ecoimmunology, in particular the thorny issue of what ecoimmunologists should, should not, or cannot measure, and what novel contributions ecoimmunologists have made to the understanding of host-parasite interactions. Finally, we highlight some areas to which ecoimmunology is likely to contribute in the near future.
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Affiliation(s)
- Patrick M Brock
- *Department of Infectious Disease Epidemiology, Imperial College London, London, UK; Center for Infectious Disease Dynamics, Penn State University, PA, USA; Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Courtney C Murdock
- *Department of Infectious Disease Epidemiology, Imperial College London, London, UK; Center for Infectious Disease Dynamics, Penn State University, PA, USA; Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Lynn B Martin
- *Department of Infectious Disease Epidemiology, Imperial College London, London, UK; Center for Infectious Disease Dynamics, Penn State University, PA, USA; Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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34
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Hangartner S, Sbilordo SH, Michalczyk Ł, Gage MJ, Martin OY. Are there genetic trade-offs between immune and reproductive investments in Tribolium castaneum? INFECTION GENETICS AND EVOLUTION 2013; 19:45-50. [DOI: 10.1016/j.meegid.2013.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 05/21/2013] [Accepted: 06/09/2013] [Indexed: 11/16/2022]
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Martínez-Padilla J, Redpath SM, Zeineddine M, Mougeot F. Insights into population ecology from long-term studies of red grouseLagopus lagopus scoticus. J Anim Ecol 2013; 83:85-98. [DOI: 10.1111/1365-2656.12098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 04/30/2013] [Indexed: 01/17/2023]
Affiliation(s)
- Jesus Martínez-Padilla
- Museo Nacional de Ciencias Naturales; Department of Evolutionary Biology; José Guitérrez Abascal 2 28006 Madrid Spain
| | - Steve M. Redpath
- ACES; Department of Biological Sciences; University of Aberdeen; Zoology Building Tillydrone Av. Aberdeen AB24 2TZ UK
| | - Mohammed Zeineddine
- ACES; Department of Biological Sciences; University of Aberdeen; Zoology Building Tillydrone Av. Aberdeen AB24 2TZ UK
| | - François Mougeot
- EEZA-CSIC; La Cañada de San Urbano; 04120 Almeria Spain
- IREC (CSIC-UCLM-JCCM); Ronda de Toledo s/n 13005 Ciuada Real Spain
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36
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Järvistö PE, Laaksonen T, Calhim S. Forehead Patch Size Predicts the Outcome of Male-Male Competition in the Pied Flycatcher. Ethology 2013. [DOI: 10.1111/eth.12107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Toni Laaksonen
- Department of Biology; University of Turku; Turku; Finland
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37
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Trappett A, Condon CH, White C, Matthews P, Wilson RS. Extravagant ornaments of male threadfin rainbowfish (Iriatherina werneri) are not costly for swimming. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12097] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew Trappett
- School of Biological Sciences; The University of Queensland; St Lucia; QLD; 4072; Australia
| | - Catriona H. Condon
- School of Biological Sciences; The University of Queensland; St Lucia; QLD; 4072; Australia
| | - Craig White
- School of Biological Sciences; The University of Queensland; St Lucia; QLD; 4072; Australia
| | - Phil Matthews
- School of Biological Sciences; The University of Queensland; St Lucia; QLD; 4072; Australia
| | - Robbie S. Wilson
- School of Biological Sciences; The University of Queensland; St Lucia; QLD; 4072; Australia
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38
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Increased exposure to yolk testosterone has feminizing effects in chickens, Gallus gallus domesticus. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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39
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Kuo CC, Yao CJ, Lin TE, Liu HC, Hsu YC, Hsieh MK, Huang WS. Tail loss compromises immunity in the many-lined skink, Eutropis multifasciata. Naturwissenschaften 2013; 100:379-84. [PMID: 23503765 DOI: 10.1007/s00114-013-1032-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 11/28/2022]
Abstract
Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies.
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Affiliation(s)
- Chi-Chien Kuo
- Department of Zoology, National Museum of Natural Science, Taichung, Taiwan
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40
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Downs CJ, Brown JL, Wone B, Donovan ER, Hunter K, Hayes JP. Selection for increased mass-independent maximal metabolic rate suppresses innate but not adaptive immune function. Proc Biol Sci 2013; 280:20122636. [PMID: 23303541 DOI: 10.1098/rspb.2012.2636] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Both appropriate metabolic rates and sufficient immune function are essential for survival. Consequently, eco-immunologists have hypothesized that animals may experience trade-offs between metabolic rates and immune function. Previous work has focused on how basal metabolic rate (BMR) may trade-off with immune function, but maximal metabolic rate (MMR), the upper limit to aerobic activity, might also trade-off with immune function. We used mice artificially selected for high mass-independent MMR to test for trade-offs with immune function. We assessed (i) innate immune function by quantifying cytokine production in response to injection with lipopolysaccharide and (ii) adaptive immune function by measuring antibody production in response to injection with keyhole limpet haemocyanin. Selection for high mass-independent MMR suppressed innate immune function, but not adaptive immune function. However, analyses at the individual level also indicate a negative correlation between MMR and adaptive immune function. By contrast BMR did not affect immune function. Evolutionarily, natural selection may favour increasing MMR to enhance aerobic performance and endurance, but the benefits of high MMR may be offset by impaired immune function. This result could be important in understanding the selective factors acting on the evolution of metabolic rates.
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Affiliation(s)
- Cynthia J Downs
- Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV 89557, USA.
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41
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McCullough EL, Weingarden PR, Emlen DJ. Costs of elaborate weapons in a rhinoceros beetle: how difficult is it to fly with a big horn? Behav Ecol 2012. [DOI: 10.1093/beheco/ars069] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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42
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Koskella B, Lin DM, Buckling A, Thompson JN. The costs of evolving resistance in heterogeneous parasite environments. Proc Biol Sci 2011; 279:1896-903. [PMID: 22171085 DOI: 10.1098/rspb.2011.2259] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The evolution of host resistance to parasites, shaped by associated fitness costs, is crucial for epidemiology and maintenance of genetic diversity. Selection imposed by multiple parasites could be a particularly strong constraint, as hosts either accumulate costs of multiple specific resistances or evolve a more costly general resistance mechanism. We used experimental evolution to test how parasite heterogeneity influences the evolution of host resistance. We show that bacterial host populations evolved specific resistance to local bacteriophage parasites, regardless of whether they were in single or multiple-phage environments, and that hosts evolving with multiple phages were no more resistant to novel phages than those evolving with single phages. However, hosts from multiple-phage environments paid a higher cost, in terms of population growth in the absence of phage, for their evolved specific resistances than those from single-phage environments. Given that in nature host populations face selection pressures from multiple parasite strains and species, our results suggest that costs may be even more critical in shaping the evolution of resistance than previously thought. Furthermore, our results highlight that a better understanding of resistance costs under combined control strategies could lead to a more 'evolution-resistant' treatment of disease.
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Affiliation(s)
- Britt Koskella
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA.
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43
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Muck C, Goymann W. Throat patch size and darkness covaries with testosterone in females of a sex-role reversed species. Behav Ecol 2011. [DOI: 10.1093/beheco/arr133] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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45
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Casagrande S, Groothuis TGG. The interplay between gonadal steroids and immune defence in affecting a carotenoid-dependent trait. Behav Ecol Sociobiol 2011; 65:2007-2019. [PMID: 21957328 PMCID: PMC3172405 DOI: 10.1007/s00265-011-1210-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/30/2011] [Accepted: 05/31/2011] [Indexed: 02/03/2023]
Abstract
The hypothesis that sexual ornaments are honest signals of quality because their expression is dependent on hormones with immune-depressive effects has received ambiguous support. The hypothesis might be correct for those signals that are carotenoid-dependent because the required carotenoid deposition in the signal, stimulated by testosterone, might lower the carotenoid-dependent immune defence of the organism. Two pathways underlying this androgen-dependent honest signaling have been suggested. Firstly, androgens that are needed for ornament expression may suppress immune defence, a cost that only high-quality animals can afford. Alternatively, immune activation may downregulate the production of androgens in low-quality individuals. Which of these alternatives is correct, and to what extent these effects are mediated by the different metabolites of androgens, remain open questions. To provide answers to these questions, we manipulated the levels of testosterone (T), 5α-dihydrotestosterone (DHT), and 17-β-estradiol (E2) in diamond doves Geopelia cuneata, a species in which both sexes exhibit a carotenoid-dependent, androgen-regulated red–orange periorbital ring of bare skin. On the first day of the experiment (day 0), we inserted steroid-releasing implants into groups of birds and on day 14, we subjected half of the birds to an immunological challenge by immunizing them with sheep red blood cells (SRBC). In females, but not in males, androgen but not estradiol treatments reduced antibody production to SRBC. In addition, the immunological challenge reduced redness and size of the trait as well as androgens levels in both sexes and in all treatments. This indicates that an immunological challenge can lower circulating T at the cost of the trait expression. These findings are in accordance with both pathways postulated in the immunocompetence-handicap hypothesis, but do not entirely support the idea that the immunosuppressive effect of androgens yields honest signaling since both T and DHT were not immunosuppressive in males, for which sexual signaling is supposed to be especially important.
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Affiliation(s)
- Stefania Casagrande
- Behavioural Biology, Centre for Behaviour and Neuroscience, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
- Department of Evolutionary and Functional Biology, University of Parma, 43100 Parma, Italy
| | - Ton G. G. Groothuis
- Behavioural Biology, Centre for Behaviour and Neuroscience, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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46
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WRIGHT D, RUBIN CJ, MARTINEZ BARRIO A, SCHÜTZ K, KERJE S, BRÄNDSTRÖM H, KINDMARK A, JENSEN P, ANDERSSON L. The genetic architecture of domestication in the chicken: effects of pleiotropy and linkage. Mol Ecol 2010; 19:5140-56. [DOI: 10.1111/j.1365-294x.2010.04882.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Schroderus E, Jokinen I, Koivula M, Koskela E, Mappes T, Mills S, Oksanen T, Poikonen T. Intra‐ and Intersexual Trade‐Offs between Testosterone and Immune System: Implications for Sexual and Sexually Antagonistic Selection. Am Nat 2010; 176:E90-7. [DOI: 10.1086/656264] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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48
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Greiner S, Stefanski V, Dehnhard M, Voigt CC. Plasma testosterone levels decrease after activation of skin immune system in a free-ranging mammal. Gen Comp Endocrinol 2010; 168:466-73. [PMID: 20600041 DOI: 10.1016/j.ygcen.2010.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 06/16/2010] [Accepted: 06/19/2010] [Indexed: 11/26/2022]
Abstract
The immunocompetence handicap hypothesis (ICHH) postulates a trade-off between the display of androgen-related, sexually selected traits and investment in immune functions, often summarized as immunosuppression by testosterone (TE). We investigated the relationship between delayed type hypersensitivity (DTH) skin responses and the endocrine system in a free-ranging mammal and asked: (i) are high plasma TE levels related to a weak DTH response or (ii) does an activation of the cellular immune system cause a decrease in plasma TE secretion? and (iii) does baseline cortisol (CORT) and the capacity to release CORT in response to stress influence the DTH response? We studied these questions in the bat Carollia perspicillata and conducted an immune challenge (IC), a DTH skin test with the antigen 1,4-dinitrofluorobenzene (DNFB), as a measure for antigen-specific cell-mediated immunity. We found a high individual variance in DTH response irrespective of sex. In addition, pre-IC plasma TE did not affect the extent of DTH responses, but instead the IC lowered post-IC TE titres in both sexes. Also, pre-IC baseline CORT titres did not influence the DTH responses significantly, but the extent of an induced CORT response was negatively related to the DTH reaction. Our study does not support the presumption of an immunosuppressive effect of TE, but suggests that an activation of the immune system reduces plasma TE. This is still in line with the ICHH as originally formulated, because only immunocompetent animals are able to cope with pathogens effectively and maintain high TE levels at the same time.
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Affiliation(s)
- Sabine Greiner
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str 17, 10315 Berlin, Germany.
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49
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Bill color, not badge size, indicates testosterone-related information in house sparrows. Behav Ecol Sociobiol 2010; 64:1461-1471. [PMID: 20730125 PMCID: PMC2920409 DOI: 10.1007/s00265-010-0961-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 03/04/2010] [Accepted: 04/14/2010] [Indexed: 11/17/2022]
Abstract
The honesty of ornamental signals of quality is often argued to be enforced via costs associated with testosterone. It is still poorly understood, however, how seasonal variation of testosterone within individuals is related to the timing and extent of ornament development. Here, we studied inter- and intra-individual variability of plasma testosterone levels in a population of 150 captive male house sparrows (Passer domesticus) through the course of a full year. We further analyzed the relationship between plasma testosterone levels and two sexually dimorphic ornaments: badge size and bill coloration. Also, because of a known negative relation between molt and circulating testosterone levels, we analyzed the relationship between ornamentation and molt status during the fall. We found that testosterone levels increased towards the breeding season and decreased before the onset of annual molt. However, within individuals, relative testosterone titers demonstrated low repeatability between seasons. Plasma testosterone levels were not correlated with badge size in any season but were correlated strongly with bill coloration during all periods, except the breeding season when variation in bill color was low. Finally, we found that bill coloration strongly correlated with molt status during fall. Our results indicate that bill coloration, not badge size, is the best ornamental indicator of a “running average” of male testosterone in house sparrows and therefore the best potential indicator of qualities and/or behavioral strategies associated with testosterone.
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50
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Huyghe K, Van Oystaeyen A, Pasmans F, Tadić Z, Vanhooydonck B, Van Damme R. Seasonal changes in parasite load and a cellular immune response in a colour polymorphic lizard. Oecologia 2010; 163:867-74. [PMID: 20454978 DOI: 10.1007/s00442-010-1646-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 04/15/2010] [Indexed: 11/29/2022]
Abstract
Permanent colour polymorphisms may be maintained by complex interactions between physiological traits (e.g. immunity) and environmental pressures. In this study we investigate morph specific variation in parasite load and cellular immune response (induced by a Phytohaemagglutinin, PHA injection) in a colour polymorphic population of the Dalmatian wall lizard (Podarcis melisellensis), where adult males have bright white, yellow or orange throats and ventral sides. Orange males have larger heads and can bite harder than the others. To examine seasonal effects, analyses were performed at an early and late stage in the reproductive season (May and September). Infection with mites and ticks did not differ among morphs, but was more severe at the end of the reproductive season. Fewer orange individuals were infected with haemogregarines at the end of the season, but white males were always more infected (higher number of haemogregarines in their blood) than other morphs. White and yellow males showed an increased PHA response towards the end of the season, but PHA response decreased in the orange morph. Finally, across all morphs, a relationship was found between ectoparasite load and PHA response. Our study provides indications of alternative life-history strategies among colour morphs and evidence for an up-regulation of the immune function at the end of the reproductive season.
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Affiliation(s)
- Katleen Huyghe
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales-CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain.
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