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Revathi Venkateswaran V, Gokhale CS, Mangel M, Eliassen S. Effects of time spent in pregnancy or brooding on immunocompetence. Ecol Evol 2024; 14:e10764. [PMID: 38187919 PMCID: PMC10767163 DOI: 10.1002/ece3.10764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/05/2023] [Accepted: 11/10/2023] [Indexed: 01/09/2024] Open
Abstract
Sexes of a species may show different characteristics beyond the differences in their sexual organs and such sexual dimorphism often occurs in the level of immune response when exposed to pathogens (immunocompetence). In general, females have increased longevity relative to males, which is associated with higher immunocompetence. However, males have higher immunocompetence in some species, such as pipefishes and seahorses. Experimental evidence suggests that this could be because males, rather than females, carry fertilized eggs to birth in these species. This observation suggests that an increase in immunocompetence may be related to the level of parental investment and not to a particular sex. We use state-dependent life-history theory to study optimal investment in offspring production relative to parent immunocompetence, varying the relative time that a parent spends in brooding or pregnancy within a breeding cycle. When offspring is dependent on a parent's survival for a large part of the breeding cycle, we predict higher investments in immunity and longer life expectancies.
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Affiliation(s)
- Vandana Revathi Venkateswaran
- Research Group for Theoretical Models of Eco‐evolutionary Dynamics, Department of Evolutionary TheoryMax Planck Institute for Evolutionary BiologyPlönGermany
- Department of Plant Biology, School of Integrative BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | - Chaitanya S. Gokhale
- Research Group for Theoretical Models of Eco‐evolutionary Dynamics, Department of Evolutionary TheoryMax Planck Institute for Evolutionary BiologyPlönGermany
| | - Marc Mangel
- Institute of Marine Sciences and Department of Applied MathematicsUniversity of CaliforniaSanta CruzCaliforniaUSA
- Theoretical Ecology Group, Department of Biological SciencesUniversity of BergenBergenNorway
| | - Sigrunn Eliassen
- Theoretical Ecology Group, Department of Biological SciencesUniversity of BergenBergenNorway
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2
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Strijker BN, Iwińska K, van der Zalm B, Zub K, Boratyński JS. Is personality and its association with energetics sex-specific in yellow-necked mice Apodemus flavicollis? Ecol Evol 2023; 13:e10233. [PMID: 37408630 PMCID: PMC10318423 DOI: 10.1002/ece3.10233] [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: 01/06/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 07/07/2023] Open
Abstract
For the last two decades, behavioral physiologists aimed to explain a plausible covariation between energetics and personality, predicted by the "pace-of-life syndrome" (POLS) hypothesis. However, the results of these attempts are mixed with no definitive answer as to which of the two most acknowledged models "performance" or "allocation" predicts covariation between consistent among-individual variation in metabolism and repeatable behavior (animal personality). The general conclusion is that the association between personality and energetics is rather context-dependent. Life-history, behavior, and physiology as well as its plausible covariation can be considered a part of sexual dimorphism. However, up to now, only a few studies demonstrated a sex-specific correlation between metabolism and personality. Therefore, we tested the relationships between physiological and personality traits in a single population of yellow-necked mice Apodemus flavicollis in the context of a plausible between-sexes difference in this covariation. We hypothesized that the performance model will explain proactive behavior in males and the allocation model will apply to females. Behavioral traits were determined using the latency of risk-taking and the open field tests, whereas the basal metabolic rates (BMR) was measured using indirect calorimetry. We have found a positive correlation between body mass-adjusted BMR and repeatable proactive behavior in male mice, which can support the performance model. However, the females were rather consistent mainly in avoidance of risk-taking that did not correlate with BMR, suggesting essential differences in personality between sexes. Most likely, the lack of convincing association between energetics and personality traits at the population level is caused by a different selection acting on the life histories of males and females. This may only result in weak support for the predictions of the POLS hypothesis when assuming that only a single model explaining the link between physiology and behavior operates in males and females. Thus, there is a need to consider the differences between sexes in behavioral studies to evaluate this hypothesis.
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Affiliation(s)
- Beau N. Strijker
- Van Hall LarensteinUniversity of Applied SciencesLeeuwardenThe Netherlands
| | - Karolina Iwińska
- University of Białystok Doctoral School in Exact and Natural SciencesBiałystokPoland
- Mammal Research InstitutePolish Academy of SciencesBiałowieżaPoland
| | - Bram van der Zalm
- Van Hall LarensteinUniversity of Applied SciencesLeeuwardenThe Netherlands
| | - Karol Zub
- Mammal Research InstitutePolish Academy of SciencesBiałowieżaPoland
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3
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Nakazawa T, Kishi S. Pollinator sex matters in competition and coexistence of co-flowering plants. Sci Rep 2023; 13:4497. [PMID: 36934149 PMCID: PMC10024751 DOI: 10.1038/s41598-023-31671-z] [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: 12/07/2022] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
Male and female pollinators often exhibit sex-specific preferences for visiting different flowers. Recent studies have shown that these preferences play an important role in shaping the network structure of pollination mutualism, but little is known about how they can mediate plant-plant interactions and coexistence of competing plants. The ecological consequences of sex-specific pollination can be complex. Suppose that a plant is favoured by female pollinators. They produce male pollinators, who may prefer visiting other competing plants and intensify the negative effects of inter-plant competition. Here, we analysed a simple two plant-one pollinator model with the sex structure of the pollinator. We observed that (i) sex-specific pollination can have complex consequences for inter-plant competition and coexistence (e.g. the occurrence of non-trivial alternative stable states in which one plant excludes or coexists with the other depending on the initial conditions), (ii) male and female pollinators have distinct ecological consequences because female pollinators have a demographic impact owing to reproduction, and (iii) plants are likely to coexist when male and female pollinators prefer different plants. These results suggest that sex-specific pollination is crucial for competition and coexistence of co-flowering plants. Future, pollination research should more explicitly consider the sex-specific behaviour of pollinating animals.
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Affiliation(s)
- Takefumi Nakazawa
- Department of Life Sciences, National Cheng Kung University, Tainan City, Taiwan.
| | - Shigeki Kishi
- Research Center for Agricultural Information Technology, National Agriculture and Food Research Organization, Tsukuba, Japan
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4
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On maternity and the stronger immune response in women. Nat Commun 2022; 13:4858. [PMID: 35982048 PMCID: PMC9386672 DOI: 10.1038/s41467-022-32569-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 08/08/2022] [Indexed: 11/09/2022] Open
Abstract
Medical research reports that women often exhibit stronger immune responses than men, while pathogens tend to be more virulent in men. Current explanations cannot account for this pattern, creating an obstacle for our understanding of infectious-disease outcomes and the incidence of autoimmune diseases. We offer an alternative explanation that relies on a fundamental difference between the sexes: maternity and the opportunities it creates for transmission of pathogens from mother to child (vertical transmission). Our explanation relies on a mathematical model of the co-evolution of host immunocompetence and pathogen virulence. Here, we show that when there is sufficient vertical transmission co-evolution leads women to defend strongly against temperate pathogens and men to defend weakly against aggressive pathogens, in keeping with medical observations. From a more applied perspective, we argue that limiting vertical transmission of infections would alleviate the disproportionate incidence of autoimmune diseases in women over evolutionary time. Women generally mount a stronger immune response to infections than men do, resulting in a higher impact of autoimmune diseases. Here, the authors show that pathogen transmission from mother-to-child during pregnancy drives the co-evolution of a stout defence against harmless pathogens in women.
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5
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Barletta Ferreira AB, Bahia AC, Pitaluga AN, Barros E, Gama dos Santos D, Bottino-Rojas V, Kubota MS, Oliveira PLD, Pimenta PFP, Traub-Csekö YM, Sorgine MHF. Sexual Dimorphism in Immune Responses and Infection Resistance in Aedes aegypti and Other Hematophagous Insect Vectors. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.847109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sexual dimorphism in immune function is prevalent across different species, where males trade their ability to fight pathogens for a practical reproductive function while females favor an extended lifespan. In insects, these differences in immune function reflect an evolutionary life strategy, where females have a presumably more robust immune system than insect males. Here, we evaluate immune functioning in four male and female insect vectors, Aedes aegypti (Diptera, Culicidae), Anopheles aquasalis (Diptera, Culicidae), Lutzomyia longipalpis (Diptera, Psychodidae) and Rhodnius prolixus (Hemiptera, Reduviidae). We show evidence that challenges the concept of immune sexual dimorphism in three of these insect vectors. In the three Diptera species, A. aegypti, A. aquasalis and L. longipalpis that transmit arboviruses, Plasmodium spp. (Haemospororida, Plasmodiidae) and Leishmania spp. (Trypanosomatida, Trypanosomatidae), respectively, unchallenged adult males express higher levels of immune-related genes than adult females and immature developmental stages. The main components of the Toll, IMD, and Jak/STAT pathways and antimicrobial effectors are highly expressed in whole-body males. Additionally, males present lower midgut basal microbiota levels than females. In A. aegypti mosquitoes, the differences in immune gene expression and microbiota levels are established in adult mosquitoes but are not present at the recently emerged adults and pupal stage. Antibiotic treatment does not affect the consistently higher expression of immune genes in males, except defensin, which is reduced significantly after microbiota depletion and restored after re-introduction. Our data suggest that Diptera males have a basal state of activation of the immune system and that activation of a more robust response through systemic immune challenge acutely compromises their survival. The ones who survive clear the infection entirely. Females follow a different strategy where a moderate immune reaction render higher tolerance to infection and survival. In contrast, hematophagous adult males of the Hemiptera vector R. prolixus, which transmits Trypanosoma cruzi, present no differences in immune activation compared to females, suggesting that diet differences between males and females may influence immune sexual dimorphism. These findings expand our understanding of the biology of insect vectors of human pathogens, which can help to direct the development of new strategies to limit vector populations.
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Corripio-Miyar Y, Hayward A, Lemon H, Sweeny AR, Bal X, Kenyon F, Pilkington JG, Pemberton JM, Nussey DH, McNeilly TN. Functionally distinct T-helper cell phenotypes predict resistance to different types of parasites in a wild mammal. Sci Rep 2022; 12:3197. [PMID: 35210503 PMCID: PMC8873199 DOI: 10.1038/s41598-022-07149-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/04/2022] [Indexed: 12/31/2022] Open
Abstract
The adaptive immune system is critical to an effective response to infection in vertebrates, with T-helper (Th) cells pivotal in orchestrating these responses. In natural populations where co-infections are the norm, different Th responses are likely to play an important role in maintaining host health and fitness, a relationship which remains poorly understood in wild animals. In this study, we characterised variation in functionally distinct Th responses in a wild population of Soay sheep by enumerating cells expressing Th-subset specific transcription factors and quantifying Th-associated cytokines. We tested the prediction that raised Th1 and Th2 responses should predict reduced apicomplexan and helminth parasite burdens, respectively. All measures of Th-associated cytokine production increased with age, while Th17- and regulatory Th-associated cytokine production increased more rapidly with age in males than females. Independent of age, sex, and each other, IL-4 and Gata3 negatively predicted gastro-intestinal nematode faecal egg count, while IFN-γ negatively predicted coccidian faecal oocyst count. Our results provide important support from outside the laboratory that Th1 and Th2 responses predict resistance to different kinds of parasites, and illustrate how harnessing specific reagents and tools from laboratory immunology will illuminate our understanding of host-parasite interactions in the wild.
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Affiliation(s)
- Yolanda Corripio-Miyar
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, UK.
| | - Adam Hayward
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, UK
| | - Hannah Lemon
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Amy R Sweeny
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Xavier Bal
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Fiona Kenyon
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Daniel H Nussey
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, UK
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7
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Bichet C, Moiron M, Matson KD, Vedder O, Bouwhuis S. Immunosenescence in the wild? A longitudinal study in a long-lived seabird. J Anim Ecol 2021; 91:458-469. [PMID: 34850397 DOI: 10.1111/1365-2656.13642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 11/18/2021] [Indexed: 01/03/2023]
Abstract
Longitudinal studies of various vertebrate populations have demonstrated senescent declines in reproductive performance and survival probability to be almost ubiquitous. Longitudinal studies of potential underlying proximate mechanisms, however, are still scarce. Due to its critical function in the maintenance of health and viability, the immune system is among the potential (mediators of) proximate mechanisms that could underlie senescence. Here, we studied three innate immune parameters-haemagglutination titre, haemolysis titre and haptoglobin concentration-in a population of common terns (Sterna hirundo) known to undergo actuarial senescence. We repeatedly sampled birds of known sex and age across 11 years and used random regression models to (a) quantify how immune parameters vary among individuals and (b) describe within-individual age-specific changes in, and potential trade-offs between, immune parameters. Our models revealed no differences between males and females in haemagglutination titre and haptoglobin concentration, and very low among-individual variation in these parameters in general. Within individuals, haemagglutination titre increased with age, while haptoglobin concentration did not change. We found no indication for selective (dis)appearance in relation to haemagglutination titre or haptoglobin concentration, nor for the existence of a trade-off between them. Haemolysis was absent in the majority (76%) of samples. Common terns do not exhibit clear senescence in haemagglutination titre and haptoglobin concentration and show very little among-individual variation in these parameters in general. This may be explained by canalisation of the immune parameters or by the colonial breeding behaviour of our study species, but more longitudinal studies are needed to facilitate investigation of links between species' characteristics and immunosenescence in wild animals.
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Affiliation(s)
- Coraline Bichet
- Institute of Avian Research, Wilhelmshaven, Germany.,Centre d'Etudes Biologiques de Chizé, CNRS-La Rochelle Université, UMR-7372, Villiers-en-Bois, France
| | - Maria Moiron
- Institute of Avian Research, Wilhelmshaven, Germany.,CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
| | - Kevin D Matson
- Wildlife Ecology and Conservation, Environmental Sciences Group, Wageningen University, Wageningen, The Netherlands
| | - Oscar Vedder
- Institute of Avian Research, Wilhelmshaven, Germany
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8
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de Araújo Albuquerque LP, da Silva AM, de Araújo Batista FM, de Souza Sene I, Costa DL, Costa CHN. Influence of sex hormones on the immune response to leishmaniasis. Parasite Immunol 2021; 43:e12874. [PMID: 34309860 DOI: 10.1111/pim.12874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/23/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022]
Abstract
The differences in morbidity and mortality patterns and life expectancy between the sexes are well established in different infectious and parasitic conditions, such as in leishmaniases, in which biological, genetic, sexual and hormonal variations can modulate the immune response indicating greater infectivity, prevalence and clinical severity in men. In this regard, in seeking the understanding of factors related to protection and susceptibility to infection, this review aimed to discuss the influence of sex hormones on the immune response to leishmaniases. In the literature, sex hormone variations promote differences in the innate, humoral and cell-mediated immune response, leading to greater susceptibility, mortality and complications in males. Epidemiological estimates confirm these results, showing a predominance of the disease, in its different clinical forms, in men and suggesting that sexual variations influence immunomodulatory mechanisms since the prevalence of cases comprises the post-puberty and adulthood period. In this perspective, the action of sex hormones has been investigated in different clinical models, highlighting the potential of testosterone in immunosuppression, given its association with greater susceptibility and poor control of parasite load and the induction of cell apoptosis and attenuation of pro-inflammatory signalling pathways. Therefore, hormonal variations influence the immune response among males and females against leishmaniases, in which androgens may present immunosuppressive potential, while steroids present immunomodulatory characteristics.
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Affiliation(s)
| | - Amanda Miranda da Silva
- Postgraduate Program in Biotechnology, Northeast Network of Biotechnology, Federal University of Piauí, Teresina, Brazil.,Leishmaniasis Laboratory, Federal University of Piauí, Teresina, Brazil
| | | | | | - Dorcas Lamounier Costa
- Maternal and Child Department, Federal University of Piauí and Intelligence Center in Emerging and Neglected Tropical Conditions (CIATEN, Teresina, Brazil
| | - Carlos Henrique Nery Costa
- Community Medicine Department, Federal University of Piauí and Intelligence Center in Emerging and Neglected Tropical Conditions (CIATEN, Teresina, Brazil
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9
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Nystrand M, Dowling DK. Effects of immune challenge on expression of life-history and immune trait expression in sexually reproducing metazoans-a meta-analysis. BMC Biol 2020; 18:135. [PMID: 33028304 PMCID: PMC7541220 DOI: 10.1186/s12915-020-00856-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/25/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Life-history theory predicts a trade-off between investment into immune defence and other fitness-related traits. Accordingly, individuals are expected to upregulate their immune response when subjected to immune challenge. However, this is predicted to come at the expense of investment into a range of other traits that are costly to maintain, such as growth, reproduction and survival. Currently, it remains unclear whether the magnitude of such costs, and trade-offs involving immune investment and other traits, manifests consistently across species and sexes. To address this, we conducted a meta-analysis to investigate how changes in sex, ontogenetic stage and environmental factors shape phenotypic trait expression following an immune challenge. RESULTS We explored the effects of immune challenge on three types of traits across sexually reproducing metazoans: life-history, morphological and proximate immune traits (235 effect sizes, 53 studies, 37 species [21 invertebrates vs. 16 vertebrates]). We report a general negative effect of immune challenge on survival and reproduction, a positive effect on immune trait expression, but no effect on morphology or development time. The negative effects of immune challenge on reproductive traits and survival were larger in females than males. We also report a pronounced effect of the immune treatment agent used (e.g. whether the treatment involved a live pathogen or not) on the host response to immune challenge, and find an effect of mating status on the host response in invertebrates. CONCLUSION These results suggest that costs associated with immune deployment following an immune challenge are context-dependent and differ consistently in their magnitude across the sexes of diverse taxonomic lineages. We synthesise and discuss the outcomes in the context of evolutionary theory on sex differences in life-history and highlight the need for future studies to carefully consider the design of experiments aimed at disentangling the costs of immune deployment.
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Affiliation(s)
- M. Nystrand
- School of Biological Sciences, Monash University, Clayton, Victoria 3800 Australia
| | - D. K. Dowling
- School of Biological Sciences, Monash University, Clayton, Victoria 3800 Australia
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10
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van Lieshout SHJ, Badás EP, Mason MWT, Newman C, Buesching CD, Macdonald DW, Dugdale HL. Social effects on age-related and sex-specific immune cell profiles in a wild mammal. Biol Lett 2020; 16:20200234. [PMID: 32673548 PMCID: PMC7423055 DOI: 10.1098/rsbl.2020.0234] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Evidence for age-related changes in innate and adaptive immune responses is increasing in wild populations. Such changes have been linked to fitness, and knowledge of the factors driving immune response variation is important for understanding the evolution of immunity. Age-related changes in immune profiles may be owing to factors such as immune system development, sex-specific behaviour and responses to environmental conditions. Social environments may also contribute to variation in immunological responses, for example, through transmission of pathogens and stress arising from resource and mate competition. Yet, the impact of the social environment on age-related changes in immune cell profiles is currently understudied in the wild. Here, we tested the relationship between leukocyte cell composition (proportion of neutrophils and lymphocytes [innate and adaptive immunity, respectively] that were lymphocytes) and age, sex and group size in a wild population of European badgers (Meles meles). We found that the proportion of lymphocytes in early life was greater in males in smaller groups compared to larger groups, but with a faster age-related decline in smaller groups. By contrast, the proportion of lymphocytes in females was not significantly related to age or group size. Our results provide evidence of sex-specific age-related changes in immune cell profiles in a wild mammal, which are influenced by the social environment.
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Affiliation(s)
- Sil H J van Lieshout
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Elisa P Badás
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Michael W T Mason
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Abingdon, Oxfordshire OX13 5QL, UK
| | - Christina D Buesching
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Abingdon, Oxfordshire OX13 5QL, UK
| | - David W Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Abingdon, Oxfordshire OX13 5QL, UK
| | - Hannah L Dugdale
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
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11
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Ehrlich RL, Zuk M. The role of sex and temperature in melanin-based immune function. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sex differences in immunity have been observed across a wide range of species. Still, it remains unclear how sex-specific interactions with the environment are linked to sex differences in immunity. We studied the plasticity of immunological sex differences by focusing on melanin-based traits in the Pacific field cricket (Teleogryllus oceanicus (Le Guillou, 1841)). Insects rely on the pigment melanin for both immune function and coloration of the cuticle; therefore, changes in melanin production for one of these traits may indirectly affect the other. Male crickets use melanized wing structures to chirp. These cuticular structures are missing in females and a songless male morph. Given that the thermal environment influences cuticle melanization, we investigated the interactive effects of sex and developmental temperature on melanin-based immunity. Both immunity and wing cuticle melanism were reduced in individuals that developed under warmer temperatures. Rearing temperature also mediated the extent to which the sexes differed in immune traits. Males had darker cuticles, whereas females expressed greater immune activity, suggesting that sex-specific investment in melanin corresponds with sex differences in immunity. However, the lack of immunological differences between the two male morphs does not support the hypothesis that investment in cuticle melanism affects investment in immunity.
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Affiliation(s)
- Rebecca L. Ehrlich
- Department of Ecology, Evolution, and Behavior, University of Minnesota-Twin Cities, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
- Department of Ecology, Evolution, and Behavior, University of Minnesota-Twin Cities, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
| | - Marlene Zuk
- Department of Ecology, Evolution, and Behavior, University of Minnesota-Twin Cities, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
- Department of Ecology, Evolution, and Behavior, University of Minnesota-Twin Cities, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
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12
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Yeh JJ, Lin CL, Hsu CY, Shae ZY, Kao CH. Association between neurodegenerative diseases and pneumonia: a retrospective population-based study. Curr Med Res Opin 2019; 35:1033-1039. [PMID: 30479164 DOI: 10.1080/03007995.2018.1552408] [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] [Indexed: 10/27/2022]
Abstract
PURPOSE The association between pneumonia and neurodegenerative diseases (NDs) has never been reported in detail. We address this relationship with reference to the general population. METHODS Using Taiwan's National Health Insurance Research Database to identify a pneumonia cohort (including the typical and atypical), we established an ND cohort of 19,062 patients and a non-ND cohort of 76,227 people. In both cohorts, the risk of pneumonia was measured using multivariable Cox proportional hazards models. RESULTS The adjusted hazard ratio (aHR) (95% confidence interval [CI]) for the pneumonia cohort was 2.10 (1.96-2.24), regardless of age, sex, comorbidities or drug use in the ND cohort. The aHR (95% CI) for adults aged 20-49 years was 2.08 (1.58-2.75), men 2.20 (2.01-2.40). However, older subjects were at greatest risk of pneumonia, (3.41 [2.99-3.88]) if the 20-49 years age group is used as the reference. For the ND and non-ND cohorts, those with comorbidities (with the exception of hyperlipidemia) had higher risk; aHR (95% CI) 2.35 (2.30-2.52). The aHR (95% CI) for those without comorbidities is 3.28 (2.52-4.26). No significant difference was observed in incidence of pneumonia between those who were and were not using statin medications; the aHR (95% CI) was 1.03 (0.93-1.14). CONCLUSION The ND cohort had a higher risk of pneumonia, regardless of age, sex, comorbidities or statin use. The risk of pneumonia was higher in elderly and male patients in the ND cohort.
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Affiliation(s)
- Jun-Jun Yeh
- a Ditmanson Medical Foundation Chia-Yi Christian Hospital , Chiayi , Taiwan
- b Chia Nan University of Pharmacy and Science , Tainan, Taiwan
- c Meiho University , Pingtung , Taiwan
- d China Medical University , Taichung , Taiwan
| | - Cheng-Li Lin
- e Management Office for Health Data, China Medical University Hospital , Taichung , Taiwan
- f College of Medicine , China Medical University , Taichung , Taiwan
| | - Chung Y Hsu
- g Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University , Taichung , Taiwan
| | - Zon-Yin Shae
- h Department of Computer Science and Information Engineering , Asia University Taichung , Taiwan
| | - Chia-Hung Kao
- g Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University , Taichung , Taiwan
- i Department of Nuclear Medicine and PET Center , China Medical University Hospital , Taichung, Taiwan
- j Department of Bioinformatics and Medical Engineering , Asia University , Taichung , Taiwan
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Kelly CD, Stoehr AM, Nunn C, Smyth KN, Prokop ZM. Sexual dimorphism in immunity across animals: a meta-analysis. Ecol Lett 2018; 21:1885-1894. [PMID: 30288910 DOI: 10.1111/ele.13164] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/16/2018] [Accepted: 09/03/2018] [Indexed: 01/03/2023]
Abstract
In animals, sex differences in immunity are proposed to shape variation in infection prevalence and intensity among individuals in a population, with females typically expected to exhibit superior immunity due to life-history trade-offs. We performed a systematic meta-analysis to investigate the magnitude and direction of sex differences in immunity and to identify factors that shape sex-biased immunocompetence. In addition to considering taxonomic and methodological effects as moderators, we assessed age-related effects, which are predicted to occur if sex differences in immunity are due to sex-specific resource allocation trade-offs with reproduction. In a meta-analysis of 584 effects from 124 studies, we found that females exhibit a significantly stronger immune response than do males, but the effect size is relatively small, and became non-significant after controlling for phylogeny. Female-biased immunity was more pronounced in adult than immature animals. More recently published studies did not report significantly smaller effect sizes. Among taxonomic and methodological subsets of the data, some of the largest effect sizes were in insects, further supporting previous suggestions that testosterone is not the only potential driver of sex differences in immunity. Our findings challenge the notion of pervasive biases towards female-biased immunity and the role of testosterone in driving these differences.
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Affiliation(s)
- Clint D Kelly
- Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, succursale Centre-Ville, Montreal, QC, H3C 3P8, Canada
| | - Andrew M Stoehr
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, USA
| | - Charles Nunn
- Department of Evolutionary Anthropology, Duke University, Science Drive, Durham, NC, 27708, USA.,Duke Global Health Institute, Duke University, Trent Drive, Durham, NC, 27710, USA
| | - Kendra N Smyth
- Department of Evolutionary Anthropology, Duke University, Science Drive, Durham, NC, 27708, USA.,University Program in Ecology, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Zofia M Prokop
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland
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14
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Sex differences in life history, behavior, and physiology along a slow-fast continuum: a meta-analysis. Behav Ecol Sociobiol 2018; 72:132. [PMID: 30100667 PMCID: PMC6060830 DOI: 10.1007/s00265-018-2534-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/19/2018] [Accepted: 06/22/2018] [Indexed: 01/04/2023]
Abstract
The pace-of-life syndrome (POLS) hypothesis predicts that behavior and physiology covary with life history. Evidence for such covariation is contradictory, possibly because systematic sources of variation (e.g. sex) have been neglected. Sexes often experience different selection pressures leading to sex-specific allocation between reproduction and self-maintenance, facilitating divergence in life-history. Sex-specific differences in means and possibly variances may therefore play a key role in the POLS framework. We investigate whether sexes differ in means and variances along the fast-slow pace-of-life continuum for life history and physiological and behavioral traits. In addition, we test whether social and environmental characteristics such as breeding strategy, mating system, and study environment explain heterogeneity between the sexes. Using meta-analytic methods, we found that populations with a polygynous mating system or for studies conducted on wild populations, males had a faster pace-of-life for developmental life-history traits (e.g., growth rate), behavior, and physiology. In contrast, adult life-history traits (e.g., lifespan) were shifted towards faster pace-of-life in females, deviating from the other trait categories. Phenotypic variances were similar between the sexes across trait categories and were not affected by mating system or study environment. Breeding strategy did not influence sex differences in variances or means. We discuss our results in the light of sex-specific selection that might drive sex-specific differences in pace-of-life and ultimately POLS.
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Merlo JL, Cutrera AP, Kittlein MJ, Zenuto RR. Individual condition and inflammatory response to PHA in the subterranean rodent Ctenomys talarum (Talas tuco-tuco): A multivariate approach. Mamm Biol 2018. [DOI: 10.1016/j.mambio.2018.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Immonen E, Hämäläinen A, Schuett W, Tarka M. Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms. Behav Ecol Sociobiol 2018; 72:60. [PMID: 29576676 PMCID: PMC5856903 DOI: 10.1007/s00265-018-2462-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 11/13/2017] [Accepted: 02/07/2018] [Indexed: 11/16/2022]
Abstract
Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration.
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Affiliation(s)
- Elina Immonen
- Department of Ecology and Genetics, Evolutionary Biology Centre (EBC), Uppsala University, Norbyvägen 18 D, SE-75 236 Uppsala, Sweden
| | - Anni Hämäläinen
- Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9 Canada
| | - Wiebke Schuett
- Zoological Institute, University of Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Maja Tarka
- Center for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5, 7491 Trondheim, Norway
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17
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18
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Rapkin J, Jensen K, Archer CR, House CM, Sakaluk SK, Castillo ED, Hunt J. The Geometry of Nutrient Space-Based Life-History Trade-Offs: Sex-Specific Effects of Macronutrient Intake on the Trade-Off between Encapsulation Ability and Reproductive Effort in Decorated Crickets. Am Nat 2018; 191:452-474. [PMID: 29570407 DOI: 10.1086/696147] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Life-history theory assumes that traits compete for limited resources, resulting in trade-offs. The most commonly manipulated resource in empirical studies is the quantity or quality of diet. Recent studies using the geometric framework for nutrition, however, suggest that trade-offs are often regulated by the intake of specific nutrients, but a formal approach to identify and quantify the strength of such trade-offs is lacking. We posit that trade-offs occur whenever life-history traits are maximized in different regions of nutrient space, as evidenced by nonoverlapping 95% confidence regions of the global maximum for each trait and large angles (θ) between linear nutritional vectors and Euclidean distances (d) between global maxima. We then examined the effects of protein and carbohydrate intake on the trade-off between reproduction and aspects of immune function in male and female Gryllodes sigillatus. Female encapsulation ability and egg production increased with the intake of both nutrients, whereas male encapsulation ability increased with protein intake but calling effort increased with carbohydrate intake. The trade-offs between traits was therefore larger in males than in females, as demonstrated by significant negative correlations between the traits in males, nonoverlapping 95% confidence regions, and larger estimates of θ and d. Under dietary choice, the sexes had similar regulated intakes, but neither optimally regulated nutrient intake for maximal trait expression. We highlight the fact that greater consideration of specific nutrient intake is needed when examining nutrient space-based trade-offs.
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Stromsland K, Zimmerman LM. Relationships between parasitic infection and natural antibodies, age, and sex in a long-lived vertebrate. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2017; 327:407-412. [PMID: 29356439 DOI: 10.1002/jez.2111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 01/18/2023]
Abstract
Reptilian immune systems are believed to rely more heavily on the innate response than the adaptive response. Past research on reptilian immune systems has indicated that natural antibodies (NAbs) play an important role in fighting antigens as the first responder and initiating the innate immune response. However, there is a gap in research on NAbs in reptiles as there is little data on how they may influence parasite prevalence in reptiles. Furthermore, no studies have examined NAbs at mucosal sites, which represent an important point of entry for parasites. We investigated NAbs in male and female red-eared slider turtles (Trachemys scripta) in order to begin to fill this gap in our understanding. Plasma and mucosal samples were collected from T. scripta to determine total immunoglobulin levels in relation to intestinal parasite load, which was determined from fecal samples. We also determined antibody levels to various antigens to examine if NAbs are present in mucosal samples and how levels compare to plasma NAbs. In female turtles, parasite intensity decreased with increasing host age and mucosal antibody levels. We also found that the levels of antibodies that bind to a novel antigen and an antigen they are likely to have encountered were significantly related in both plasma and mucosal samples, indicating a NAb response. This study contributes to our understanding of how reptiles may rely on a broad innate response that allows them to resist potential pathogens while potentially avoiding some negative consequences of immunosenescence.
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Ancell H, Pires-daSilva A. Sex-specific lifespan and its evolution in nematodes. Semin Cell Dev Biol 2017; 70:122-129. [PMID: 28554570 DOI: 10.1016/j.semcdb.2017.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/03/2017] [Accepted: 05/18/2017] [Indexed: 12/22/2022]
Abstract
Differences between sexes of the same species in lifespan and aging rate are widespread. While the proximal and evolutionary causes of aging are well researched, the factors that contribute to sex differences in these traits have been less studied. The striking diversity of nematodes provides ample opportunity to study variation in sex-specific lifespan patterns associated with shifts in life history and mating strategy. Although the plasticity of these sex differences will make it challenging to generalize from invertebrate to vertebrate systems, studies in nematodes have enabled empirical evaluation of predictions regarding the evolution of lifespan. These studies have highlighted how natural and sexual selection can generate divergent patterns of lifespan if the sexes are subject to different rates or sources of mortality, or if trade-offs between complex traits and longevity are resolved differently in each sex. Here, we integrate evidence derived mainly from nematodes that addresses the molecular and evolutionary basis of sex-specific aging and lifespan. Ultimately, we hope to generate a clearer picture of current knowledge in this area, and also highlight the limitations of our understanding.
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Affiliation(s)
- Henry Ancell
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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21
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Zimmerman LM, Carter AW, Bowden RM, Vogel LA. Immunocompetence in a long‐lived ectothermic vertebrate is temperature dependent but shows no decline in older adults. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12867] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Laura M. Zimmerman
- School of Biological Sciences Illinois State University Campus Box 4120, Normal IL 61790‐4120 USA
- Department of Biology Millikin University 1184 W. Main St., Decatur IL 62522 USA
| | - Amanda Wilson Carter
- School of Biological Sciences Illinois State University Campus Box 4120, Normal IL 61790‐4120 USA
| | - Rachel M. Bowden
- School of Biological Sciences Illinois State University Campus Box 4120, Normal IL 61790‐4120 USA
| | - Laura A. Vogel
- School of Biological Sciences Illinois State University Campus Box 4120, Normal IL 61790‐4120 USA
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22
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Segner H, Verburg-van Kemenade BML, Chadzinska M. The immunomodulatory role of the hypothalamus-pituitary-gonad axis: Proximate mechanism for reproduction-immune trade offs? DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 66:43-60. [PMID: 27404794 DOI: 10.1016/j.dci.2016.07.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 06/06/2023]
Abstract
The present review discusses the communication between the hypothalamic-pituitary-gonad (HPG) axis and the immune system of vertebrates, attempting to situate the HPG-immune interaction into the context of life history trade-offs between reproductive and immune functions. More specifically, (i) we review molecular and cellular interactions between hormones of the HPG axis, and, as far as known, the involved mechanisms on immune functions, (ii) we evaluate whether the HPG-immune crosstalk serves as proximate mechanism mediating reproductive-immune trade-offs, and (iii) we ask whether the nature of the HPG-immune interaction is conserved throughout vertebrate evolution, despite the changes in immune functions, reproductive modes, and life histories. In all vertebrate classes studied so far, HPG hormones have immunomodulatory functions, and indications exist that they contribute to reproduction-immunity resource trade-offs, although the very limited information available for most non-mammalian vertebrates makes it difficult to judge how comparable or different the interactions are. There is good evidence that the HPG-immune crosstalk is part of the proximate mechanisms underlying the reproductive-immune trade-offs of vertebrates, but it is only one factor in a complex network of factors and processes. The fact that the HPG-immune interaction is flexible and can adapt to the functional and physiological requirements of specific life histories. Moreover, the assumption of a relatively fixed pattern of HPG influence on immune functions, with, for example, androgens always leading to immunosuppression and estrogens always being immunoprotective, is probably oversimplified, but the HPG-immune interaction can vary depending on the physiological and envoironmental context. Finally, the HPG-immune interaction is not only driven by resource trade-offs, but additional factors such as, for instance, the evolution of viviparity shape this neuroendocrine-immune relationship.
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Affiliation(s)
- Helmut Segner
- Centre for Fish and Wildlife Health, Dept of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, P.O. Box, CH-3001, Bern, Switzerland.
| | - B M Lidy Verburg-van Kemenade
- Cell Biology and Immunology Group, Dept. of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH, Wageningen, The Netherlands
| | - Magdalena Chadzinska
- Department of Evolutionary Immunology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
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23
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Kelly CD. Effect of nutritional stress and sex on melanotic encapsulation rate in the sexually size dimorphic Cook Strait giant weta (Deinacrida rugosa). CAN J ZOOL 2016. [DOI: 10.1139/cjz-2016-0108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nutritional condition and sex are known to influence efficacy and investment in immune function. A poor diet is costly to immune function because it limits the resources (e.g., protein) available to effector systems (e.g., melanotic encapsulation), whereas males and females are expected to differ in how they allocate resources to fitness-related traits. Males are expected to invest less in immunity, and more in mating, than females, but this pattern could be reversed if fitness is more condition-dependent in males than in females. I tested the effects of nutritional condition and sex on melanotic encapsulation rate in the Cook Strait giant weta (Deinacrida rugosa Buller, 1871), an orthopteran insect exhibiting strong female-biased sexual size dimorphism that is, at least in part, the result of strong sexual selection for small male size. I found that male D. rugosa have a stronger encapsulation response than females, while nutritional condition has only a small positive effect on this particular effector system in both sexes. Whether the observed sex difference in encapsulation ability is due to a physiological constraint in females or whether males allocate more resources to this effector system because their fitness is more condition-dependent than female’s remains to be determined.
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Affiliation(s)
- Clint D. Kelly
- Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888 succursale Centre-Ville, Montréal, QC H3C 3P8, Canada
- Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888 succursale Centre-Ville, Montréal, QC H3C 3P8, Canada
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24
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Inagaki T, Matsuura K. Colony-dependent sex differences in protozoan communities of the lower termite Reticulitermes speratus (Isoptera: Rhinotermitidae). Ecol Res 2016. [DOI: 10.1007/s11284-016-1387-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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25
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26
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Young HS, Dirzo R, Helgen KM, McCauley DJ, Nunn CL, Snyder P, Veblen KE, Zhao S, Ezenwa VO. Large wildlife removal drives immune defence increases in rodents. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12542] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hillary S. Young
- University of California Santa Barbara Santa Barbara California 93106 USA
- Division of Mammals National Museum of Natural History Smithsonian Institution Washington District of Columbia 20013 USA
- Mpala Research Centre Box 555 Nanyuki Kenya
| | - Rodolfo Dirzo
- Department of Biology Stanford University Stanford California 94305 USA
| | - Kristofer M. Helgen
- Division of Mammals National Museum of Natural History Smithsonian Institution Washington District of Columbia 20013 USA
| | - Douglas J. McCauley
- University of California Santa Barbara Santa Barbara California 93106 USA
- Mpala Research Centre Box 555 Nanyuki Kenya
| | - Charles L. Nunn
- Department of Evolutionary Anthropology Duke University Durham North Carolina 27708 USA
- Duke Global Health Institute Duke University Durham North Carolina 27708 USA
| | - Paul Snyder
- Odum School of Ecology and Department of Infectious Diseases College of Veterinary Medicine University of Georgia Athens Georgia 30602 USA
- Department of Integrative Biology Oregon State University Corvallis Oregon 97331 USA
| | - Kari E. Veblen
- Mpala Research Centre Box 555 Nanyuki Kenya
- Department of Wildland Resources and Ecology Center Utah State University Logan Utah 84322 USA
| | - Serena Zhao
- Division of Mammals National Museum of Natural History Smithsonian Institution Washington District of Columbia 20013 USA
- Mpala Research Centre Box 555 Nanyuki Kenya
| | - Vanessa O. Ezenwa
- Mpala Research Centre Box 555 Nanyuki Kenya
- Odum School of Ecology and Department of Infectious Diseases College of Veterinary Medicine University of Georgia Athens Georgia 30602 USA
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27
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The effect of parasites on sex differences in selection. Heredity (Edinb) 2015; 114:367-72. [PMID: 25649503 DOI: 10.1038/hdy.2014.110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 10/26/2014] [Accepted: 10/27/2014] [Indexed: 11/08/2022] Open
Abstract
The life history strategies of males and females are often divergent, creating the potential for sex differences in selection. Deleterious mutations may be subject to stronger selection in males, owing to sexual selection, which can improve the mean fitness of females and reduce mutation load in sexual populations. However, sex differences in selection might also maintain sexually antagonistic genetic variation, creating a sexual conflict load. The overall impact of separate sexes on fitness is unclear, but the net effect is likely to be positive when there is a large sex difference in selection against deleterious mutations. Parasites can also have sex-specific effects on fitness, and there is evidence that parasites can intensify the fitness consequences of deleterious mutations. Using lines that accumulated mutations for over 60 generations, we studied the effect of the pathogenic bacterium Pseudomonas aeruginosa on sex differences in selection in the fruit fly Drosophila melanogaster. Pseudomonas infection increased the sex difference in selection, but may also have weakened the intersexual correlation for fitness. Our results suggest that parasites may increase the benefits of sexual selection.
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28
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Maia JP, Harris DJ, Carranza S, Gómez-Díaz E. A comparison of multiple methods for estimating parasitemia of hemogregarine hemoparasites (apicomplexa: adeleorina) and its application for studying infection in natural populations. PLoS One 2014; 9:e95010. [PMID: 24743340 PMCID: PMC3990604 DOI: 10.1371/journal.pone.0095010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 03/21/2014] [Indexed: 11/19/2022] Open
Abstract
Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in sympatric natural populations.
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Affiliation(s)
- João P. Maia
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Vila do Conde, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
- * E-mail: (JPM); (EGD)
| | - D. James Harris
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Vila do Conde, Portugal
| | - Salvador Carranza
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Elena Gómez-Díaz
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
- * E-mail: (JPM); (EGD)
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29
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Gerlinskaya LA, Zav’yalov EL, Chechulin AI, Moshkin MP. Maturation of cestodes depending on the territorial status and food supply of their host, the water vole (Arvicola terrestris). BIOL BULL+ 2013. [DOI: 10.1134/s1062359013070030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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30
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Harts AMF, Kokko H. Understanding promiscuity: when is seeking additional mates better than guarding an already found one? Evolution 2013; 67:2838-48. [PMID: 24094337 DOI: 10.1111/evo.12163] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/06/2013] [Indexed: 11/28/2022]
Abstract
Paternity protection and the acquisition of multiple mates select for different traits. The consensus from theoretical work is that mate-guarding intensifies with an increasing male bias in the adult sex ratio (ASR). A male bias can thus lead to male monogamy if guarding takes up the entire male time budget. Given that either female- or male-biased ASRs are possible, why is promiscuity clearly much more common than male monogamy? We address this question with two models, differing in whether males can assess temporal cues of female fertility. Our results confirm the importance of the ASR: guarding durations increase with decreasing female availability and increasing number of male competitors. However, several factors prevent the mating system from switching to male monogamy as soon as the ASR becomes male biased. Inefficient guarding, incomplete last male sperm precedence, any mechanism that allows sperm to fertilize eggs after the male's departure, and (in some cases) the unfeasibility of precopulatory guarding all help explain cases where promiscuity exists on its own or alongside temporally limited mate-guarding. Shortening the window of fertilization shifts guarding time budgets from the postcopulatory to the precopulatory stage.
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Affiliation(s)
- Anna M F Harts
- Division of Ecology, Evolution and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia.
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31
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Guerra-Silveira F, Abad-Franch F. Sex bias in infectious disease epidemiology: patterns and processes. PLoS One 2013; 8:e62390. [PMID: 23638062 PMCID: PMC3634762 DOI: 10.1371/journal.pone.0062390] [Citation(s) in RCA: 190] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 03/25/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Infectious disease incidence is often male-biased. Two main hypotheses have been proposed to explain this observation. The physiological hypothesis (PH) emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (BH) stresses gender-related differences in exposure. Surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans. METHODS AND FINDINGS For ten major pathogens, we tested PH and BH predictions about incidence and exposure-prevalence patterns. Compulsory-notification records (Brazil, 2006-2009) were used to estimate age-stratified ♂:♀ incidence rate ratios for the general population and across selected sociological contrasts. Exposure-prevalence odds ratios were derived from 82 published surveys. We estimated summary effect-size measures using random-effects models; our analyses encompass ∼0.5 million cases of disease or exposure. We found that, after puberty, disease incidence is male-biased in cutaneous and visceral leishmaniasis, schistosomiasis, pulmonary tuberculosis, leptospirosis, meningococcal meningitis, and hepatitis A. Severe dengue is female-biased, and no clear pattern is evident for typhoid fever. In leprosy, milder tuberculoid forms are female-biased, whereas more severe lepromatous forms are male-biased. For most diseases, male bias emerges also during infancy, when behavior is unbiased but sex steroid levels transiently rise. Behavioral factors likely modulate male-female differences in some diseases (the leishmaniases, tuberculosis, leptospirosis, or schistosomiasis) and age classes; however, average exposure-prevalence is significantly sex-biased only for Schistosoma and Leptospira. CONCLUSIONS Our results closely match some key PH predictions and contradict some crucial BH predictions, suggesting that gender-specific behavior plays an overall secondary role in generating sex bias. Physiological differences, including the crosstalk between sex hormones and immune effectors, thus emerge as the main candidate drivers of gender differences in infectious disease susceptibility.
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Affiliation(s)
- Felipe Guerra-Silveira
- Instituto Leônidas e Maria Deane – Fiocruz Amazônia, Manaus, Amazonas, Brazil
- School of Medicine, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
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Kerstes NA, Bérénos C, Martin OY. Coevolving parasites and population size shape the evolution of mating behaviour. BMC Evol Biol 2013; 13:29. [PMID: 23379749 PMCID: PMC3570307 DOI: 10.1186/1471-2148-13-29] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 01/30/2013] [Indexed: 11/27/2022] Open
Abstract
Background Coevolution with parasites and population size are both expected to influence the evolution of mating rates. To gain insights into the interaction between these dual selective factors, we used populations from a coevolution experiment with the red flour beetle, Tribolium castaneum, and its microsporidian parasite, Nosema whitei. We maintained each experimental population at two different population sizes. We assayed the mating behaviour of both males and females from coevolved and paired non-coevolved control populations after 24 generations of coevolution with parasites. Results Males from large, coevolved populations (i.e. ancestors were exposed to parasites) showed a reduced eagerness to mate compared to males from large, non-coevolved populations. But in small populations, coevolution did not lead to decreased male mating rates. Coevolved females from both large and small populations appeared to be more willing to accept mating than non-coevolved females. Conclusions This study provides unique, experimental insights into the combined roles of coevolving parasites and population size on the evolution of mating rate. Furthermore, we find that males and females respond differently to the same environmental conditions. Our results show that parasites can be key determinants of the sexual behaviour of their hosts.
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Affiliation(s)
- Niels Ag Kerstes
- ETH Zürich, Institute of Integrative Biology, Experimental Ecology, Zürich, Switzerland.
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Masri L, Schulte RD, Timmermeyer N, Thanisch S, Crummenerl LL, Jansen G, Michiels NK, Schulenburg H. Sex differences in host defence interfere with parasite-mediated selection for outcrossing during host-parasite coevolution. Ecol Lett 2013; 16:461-8. [PMID: 23301667 PMCID: PMC3655609 DOI: 10.1111/ele.12068] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/13/2012] [Accepted: 12/09/2012] [Indexed: 01/17/2023]
Abstract
The Red Queen hypothesis proposes that coevolving parasites select for outcrossing in the host. Outcrossing relies on males, which often show lower immune investment due to, for example, sexual selection. Here, we demonstrate that such sex differences in immunity interfere with parasite-mediated selection for outcrossing. Two independent coevolution experiments with Caenorhabditis elegans and its microparasite Bacillus thuringiensis produced decreased yet stable frequencies of outcrossing male hosts. A subsequent systematic analysis verified that male C. elegans suffered from a direct selective disadvantage under parasite pressure (i.e. lower resistance, decreased sexual activity, increased escape behaviour), which can reduce outcrossing and thus male frequencies. At the same time, males offered an indirect selective benefit, because male-mediated outcrossing increased offspring resistance, thus favouring male persistence in the evolving populations. As sex differences in immunity are widespread, such interference of opposing selective constraints is likely of central importance during host adaptation to a coevolving parasite.
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Affiliation(s)
- Leila Masri
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-University of Kiel, Kiel, Germany
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Lenz TL, Eizaguirre C, Rotter B, Kalbe M, Milinski M. Exploring local immunological adaptation of two stickleback ecotypes by experimental infection and transcriptome-wide digital gene expression analysis. Mol Ecol 2012; 22:774-86. [PMID: 22971109 PMCID: PMC3579235 DOI: 10.1111/j.1365-294x.2012.05756.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 07/10/2012] [Accepted: 07/15/2012] [Indexed: 11/28/2022]
Abstract
Understanding the extent of local adaptation in natural populations and the mechanisms that allow individuals to adapt to their native environment is a major avenue in molecular ecology research. Evidence for the frequent occurrence of diverging ecotypes in species that inhabit multiple ecological habitats is accumulating, but experimental approaches to understanding the biological pathways as well as the underlying genetic mechanisms are still rare. Parasites are invoked as one of the major selective forces driving evolution and are themselves dependent on the ecological conditions in a given habitat. Immunological adaptation to local parasite communities is therefore expected to be a key component of local adaptation in natural populations. Here, we use next-generation sequencing technology to compare the transcriptome-wide response of experimentally infected three-spined sticklebacks from a lake and a river population, which are known to evolve under selection by distinct parasite communities. By comparing overall gene expression levels as well as the activation of functional pathways in response to parasite exposure, we identified potential differences between the two stickleback populations at several levels. Our results suggest locally adapted patterns of gene regulation in response to parasite exposure, which may reflect different local optima in the trade-off between the benefits and the disadvantages of mounting an immune response because of quantitative differences of the local parasite communities.
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Affiliation(s)
- Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany.
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Baillie SM, Gudex-Cross D, Barraclough RK, Blanchard W, Brunton DH. Patterns in avian malaria at founder and source populations of an endemic New Zealand passerine. Parasitol Res 2012; 111:2077-89. [PMID: 22875394 DOI: 10.1007/s00436-012-3055-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 07/16/2012] [Indexed: 11/25/2022]
Abstract
Significant progress in our understanding of disease transmission in the wild can be made by examining variation in host-parasite-vector interactions after founder events of the host. This study is the first to document patterns in avian malaria, Plasmodium spp., infecting an endemic New Zealand passerine, Anthornis melanura, at multiple-host subpopulations simultaneously. We assess the Beaudoin hypothesis of bimodal seasonality and use AIC model selection to determine host factors associated with disease prevalence. We had the rare opportunity to test the enemy release hypothesis (ERH) after a recent colonisation event of the bellbird host. Four Plasmodium species were found to infect bellbirds. Temporal patterns of three exotic parasite lineages, including GRW06 Plasmodium (Huffia) elongatum, SYAT05 Plasmodium (Novyella) vaughani and a Plasmodium (Haemamoeba) relictum, were sporadic with low prevalence year round. The fourth species was an endemic parasite, an unresolved Plasmodium (Novyella) sp. here called ANME01, which exhibited a strong winter peak at the source subpopulations possibly indicating greater immune stressors at the densely populated source site. At the colonies, we observed bimodal seasonality in the prevalence of ANME01 with autumn and spring peaks. These infection peaks were male-biased, and the amplitude of sex bias was more pronounced at the newer colony perhaps due to increased seasonal competition resulting from territory instability. We observed a decrease in parasite species diversity and increase in body condition from source to founder sites, but statistical differences in the direct relationship between body condition and malaria prevalence between source and colony were weak and significant only during winter. Though our data did not strongly support the ERH, we highlight the benefits of 'conspecific release' associated with decreased population density and food competition. Our findings contribute to the identification of ecological and environmental drivers of variability in malaria transmission, which is valuable for predicting the consequences of both natural range expansions, as well as host re-introductions resulting from intensive conservation practices.
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Affiliation(s)
- Shauna M Baillie
- Institute of Natural Sciences, Massey University, Private Bag 102-904 North Shore Mail Centre, Auckland 0745, New Zealand.
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Manjerovic MB, Waterman JM. Immunological sex differences in socially promiscuous African ground squirrels. PLoS One 2012; 7:e38524. [PMID: 22715391 PMCID: PMC3371048 DOI: 10.1371/journal.pone.0038524] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 05/08/2012] [Indexed: 11/19/2022] Open
Abstract
Differences in how males and females respond to foreign antigens are common across taxa. Such sexual differences in the immune system are predicted to be greater in species with high promiscuity and sociality as these factors increase the likelihood of disease transmission. Intense sperm competition is thought to further this sexual dichotomy as increased investment in spermatogenesis likely incurs additional immunological costs. Xerus inauris, a ground squirrel found throughout southern Africa, is extremely social and promiscuous with one of the highest male reproductive investments among rodents. These life-history attributes suggest males and females should demonstrate a large dichotomy in immunity. Contrary to our prediction, we found no difference in spleen mass between the sexes. However, we did find significant biases in leukocyte types and red blood cell counts, possibly reflecting responses to parasite types. Among males, we predicted greater investments in spermatogenesis would result in reduced immunological investments. We found a negative association between testes and spleen size and a positive relationship between testes and number of lice suggesting trade-offs in reproductive investment possibly due to the costs associated with spermatogenesis and immunity. We suggest when measuring sexual differences in immunity it is important to consider the effects of reproductive pressures, parasite types, and life history costs.
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Affiliation(s)
- Mary Beth Manjerovic
- Illinois Natural History Survey/Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
| | - Jane M. Waterman
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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Freitak D, Knorr E, Vogel H, Vilcinskas A. Gender- and stressor-specific microRNA expression in Tribolium castaneum. Biol Lett 2012; 8:860-3. [PMID: 22628099 PMCID: PMC3440968 DOI: 10.1098/rsbl.2012.0273] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs mediating post-transcriptional regulation of gene expression in eukaryotes. Addressing their role in regulation of physiological adaptations to environmental stress in insects, we selected the red flour beetle Tribolium castaneum as a model. Beetles were fed with the bacterial entomopathogen Pseudomonas entomophila (to mimic natural infection), injected with peptidoglycan (experimental setting of strong immune responses) or subjected to either mild heat shock or starvation. Differential expression of selected immunity- and stress-related genes was quantified using real-time PCR, and expression and induction of 455 mature arthropod miRNAs were determined using proprietary microarrays. We found that Tribolium exhibits both gender- and stressor-specific adjustment of immune gene and miRNA expression. Strikingly, we discovered that the number of stressor-induced miRNAs in females is remarkably higher than in males. This observation could support the hypothesis called Bateman's principle in immunity that predicts gender-specific immune responses because females gain fitness through increased longevity, whereas males gain fitness by increasing mating rates. Our results suggest that Tribolium males and females display differential regulatory elements, both pre- and post-transcriptional, likely resulting from different investment strategies in life-history traits.
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Affiliation(s)
- Dalial Freitak
- Institute for Phytopathology and Applied Entomology, Justus Liebig University of Giessen, Heinrich Buff Ring 26-32, 35392 Giessen, Germany
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Selmi C, Brunetta E, Raimondo MG, Meroni PL. The X chromosome and the sex ratio of autoimmunity. Autoimmun Rev 2011; 11:A531-7. [PMID: 22155196 DOI: 10.1016/j.autrev.2011.11.024] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The number of human conditions that are currently considered to be autoimmune diseases (AID) has been steadily growing over the past decades and it is now estimated that over 10 million people are affected in the United States. One of the major shared features among AID is the predominance in the female sex which in some cases changes with the age at disease diagnosis. Numerous hypotheses have been formulated based on intuitive scientific backgrounds to justify this sex imbalance, i.e. sex hormones and reproductive factors, fetal microchimerism, other sex-related environmental factors, a skewing of the X-chromosome inactivation patterns, and major defects in sex chromosomes. Nevertheless, none of these hypotheses has thus far gathered enough convincing evidence and in most cases data are conflicting, as well illustrated by the reports on fetal microchimerism in systemic sclerosis or primary biliary cirrhosis. The present article will critically discuss the main hypotheses (loss of mosaicism, reactivation, and haploinsufficiency) that have been proposed based on findings in female patients with specific AID along with two additional mechanisms (X-chromosome vulnerability and X-linked polyamine genes) that have been observed in AID models. Further, recent data have significantly shifted the paradigm of X chromosome inactivation by demonstrating that a large number of genes can variably escape silencing on one or both chromosomes. As a result we may hypothesize that more than one mechanism may contribute to the female susceptibility to tolerance breakdown while the possibility that unknown factors may indeed protect men from AID should not be overlooked.
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Affiliation(s)
- Carlo Selmi
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis, CA, USA.
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Bonduriansky R. Sexual Selection and Conflict as Engines of Ecological Diversification. Am Nat 2011; 178:729-45. [DOI: 10.1086/662665] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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The economy of inflammation: when is less more? Trends Parasitol 2011; 27:382-7. [DOI: 10.1016/j.pt.2011.05.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 05/12/2011] [Accepted: 05/12/2011] [Indexed: 12/23/2022]
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Steiger S, Gershman SN, Pettinger AM, Eggert AK, Sakaluk SK. Sex differences in immunity and rapid upregulation of immune defence during parental care in the burying beetle, Nicrophorus orbicollis. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01895.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Mackie P, Sim F. “Resistance is useless!” … or should that be “Resistance is futile”? Public Health 2011; 125:327-8. [DOI: 10.1016/j.puhe.2011.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Cutrera AP, Zenuto RR, Lacey EA. MHC variation, multiple simultaneous infections and physiological condition in the subterranean rodent Ctenomys talarum. INFECTION GENETICS AND EVOLUTION 2011; 11:1023-36. [PMID: 21497205 DOI: 10.1016/j.meegid.2011.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 02/28/2011] [Accepted: 03/24/2011] [Indexed: 01/15/2023]
Abstract
Parasites and pathogens can play a significant role in shaping the genetic diversity of host populations, particularly at genes associated with host immune response. To explore this relationship in a natural population of vertebrates, we characterized Major Histocompatibility Complex (MHC) variation in the subterranean rodent Ctenomys talarum (the talas tuco-tuco) as a function of parasite load and ability to mount an adaptive immune response against a novel antigen. Specifically, we quantified genotypic diversity at the MHC class II DRB locus in relation to (1) natural variation in infection by multiple genera of parasites (potential agents of selection on MHC genes) and (2) antibody production in response to injection with sheep red blood cells (a measure of immunocompetence). Data were analyzed using co-inertia multivariate statistics, with epidemiological proxies for individual condition (hematocrit, leukocyte profile, body weight) and risk of parasite exposure (season of capture, sex). A significant excess of DRB heterozygotes was evident in the study population. Co-inertia analyses revealed significant associations between specific DRB alleles and both parasite load and intensity of humoral immune response against sheep red blood cells. The presence of specific DRB aminoacid sequences appeared to be more strongly associated with parasite load and response to a novel antigen than was heterozygosity at the DRB locus. These data suggest a role for parasite-driven balancing selection in maintaining MHC variation in natural populations of C. talarum. At the same time, these findings underscore the importance of using diverse parameters to study interactions among physiological conditions, immunocompetence, and MHC diversity in free-living animals that are confronted with multiple simultaneous immune challenges.
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Affiliation(s)
- Ana Paula Cutrera
- Laboratorio de Ecofisiología, Departamento de Biología, Universidad Nacional de Mar del Plata, CONICET, CC 1245, Mar del Plata, Argentina.
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Life history and mating systems select for male biased parasitism mediated through natural selection and ecological feedbacks. J Theor Biol 2011; 269:131-7. [DOI: 10.1016/j.jtbi.2010.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 09/08/2010] [Accepted: 10/04/2010] [Indexed: 01/22/2023]
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The X chromosome in immune functions: when a chromosome makes the difference. Nat Rev Immunol 2010; 10:594-604. [DOI: 10.1038/nri2815] [Citation(s) in RCA: 440] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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