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Dujon AM, Ujvari B, Tissot S, Meliani J, Rieu O, Stepanskyy N, Hamede R, Tokolyi J, Nedelcu A, Thomas F. The complex effects of modern oncogenic environments on the fitness, evolution and conservation of wildlife species. Evol Appl 2024; 17:e13763. [PMID: 39100750 PMCID: PMC11294924 DOI: 10.1111/eva.13763] [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: 01/28/2024] [Revised: 04/16/2024] [Accepted: 07/18/2024] [Indexed: 08/06/2024] Open
Abstract
Growing evidence indicates that human activities are causing cancer rates to rise in both human and wildlife populations. This is due to the inability of ancestral anti-cancer defences to cope with modern environmental risks. The evolutionary mismatch between modern oncogenic risks and evolved cancer defences has far-reaching effects on various biological aspects at different timeframes, demanding a comprehensive study of the biology and evolutionary ecology of the affected species. Firstly, the increased activation of anti-cancer defences leads to excessive energy expenditure, affecting other biological functions and potentially causing health issues like autoimmune diseases. Secondly, tumorigenesis itself can impact important fitness-related parameters such as competitiveness, predator evasion, resistance to parasites, and dispersal capacity. Thirdly, rising cancer risks can influence the species' life-history traits, often favoring early reproduction to offset fitness costs associated with cancer. However, this strategy has its limits, and it may not ensure the sustainability of the species if cancer risks continue to rise. Lastly, some species may evolve additional anti-cancer defences, with uncertain consequences for their biology and future evolutionary path. In summary, we argue that the effects of increased exposure to cancer-causing substances on wildlife are complex, ranging from immediate responses to long-term evolutionary changes. Understanding these processes, especially in the context of conservation biology, is urgently needed.
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Affiliation(s)
- Antoine M. Dujon
- School of Life and Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia
- CREEC/CANECEV (CREES), MIVEGEC, Unité Mixte de Recherches, IRD 224–CNRS 5290–Université de MontpellierMontpellierFrance
| | - Beata Ujvari
- School of Life and Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia
| | - Sophie Tissot
- CREEC/CANECEV (CREES), MIVEGEC, Unité Mixte de Recherches, IRD 224–CNRS 5290–Université de MontpellierMontpellierFrance
| | - Jordan Meliani
- CREEC/CANECEV (CREES), MIVEGEC, Unité Mixte de Recherches, IRD 224–CNRS 5290–Université de MontpellierMontpellierFrance
| | - Océane Rieu
- CREEC/CANECEV (CREES), MIVEGEC, Unité Mixte de Recherches, IRD 224–CNRS 5290–Université de MontpellierMontpellierFrance
| | - Nikita Stepanskyy
- CREEC/CANECEV (CREES), MIVEGEC, Unité Mixte de Recherches, IRD 224–CNRS 5290–Université de MontpellierMontpellierFrance
| | - Rodrigo Hamede
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Jácint Tokolyi
- Department of Evolutionary Zoology, MTA‐DE “Momentum” Ecology, Evolution and Developmental Biology Research GroupUniversity of DebrecenDebrecenHungary
| | - Aurora Nedelcu
- Department of BiologyUniversity of new BrunswickFrederictonNew BrunswickCanada
| | - Frédéric Thomas
- School of Life and Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia
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2
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Bolnick DI, Barrett RD, Choi E, Eckert L, Hendry AP, Kerns EV, Lind ÅJ, Milligan-McClellan K, Peichel CL, Sasser K, Thornton AR, Wolf C, Steinel NC, Weber JN. Destabilized host-parasite dynamics in newly founded populations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.24.600494. [PMID: 38979317 PMCID: PMC11230150 DOI: 10.1101/2024.06.24.600494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
When species disperse into previously unoccupied habitats, new populations encounter unfamiliar species interactions such as altered parasite loads. Theory predicts that newly founded populations should exhibit destabilized eco-evolutionary fluctuations in infection rates and immune traits. However, to understand founder effects biologists typically rely on retrospective studies of range expansions, missing early-generation infection dynamics. To remedy this, we experimentally founded whole-lake populations of threespine stickleback. Infection rates were temporally stable in native source lakes. In contrast, newly founded populations exhibit destabilized host-parasite dynamics: high starting infection rates led to increases in a heritable immune trait (peritoneal fibrosis), suppressing infection rates. The resulting temporal auto-correlation between infection and immunity suggest that newly founded populations can exhibit rapid host-parasite eco-evolutionary dynamics.
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Affiliation(s)
- Daniel I. Bolnick
- Department of Ecology and Evolutionary Biology, University of Connecticut Storrs CT, USA
| | | | - Emma Choi
- Department of Ecology and Evolutionary Biology, University of Connecticut Storrs CT, USA
| | - Lucas Eckert
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Andrew P. Hendry
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Emily V. Kerns
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Åsa J. Lind
- Department of Biology, McGill University, Montreal, Quebec, Canada
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | | | - Catherine L. Peichel
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Kristofer Sasser
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Alice R Thornton
- Center for Pathogen Research and Training, University of Massachusetts, Lowell, MA, USA
| | - Cole Wolf
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Natalie C. Steinel
- Center for Pathogen Research and Training, University of Massachusetts, Lowell, MA, USA
- Department of Biology, University of Massachusetts, Lowell, USA
| | - Jesse N. Weber
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
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3
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Liao A, Cavigliasso F, Savary L, Kawecki TJ. Effects of an entomopathogenic fungus on the reproductive potential of Drosophila males. Ecol Evol 2024; 14:e11242. [PMID: 38590549 PMCID: PMC10999951 DOI: 10.1002/ece3.11242] [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: 11/17/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
While mortality is often the primary focus of pathogen virulence, non-lethal consequences, particularly for male reproductive fitness, are less understood; however, they are essential for understanding how sexual selection contributes to promoting resistance. We investigated how the fungal pathogen Metarhizium brunneum affects mating ability, fertility, and seminal fluid protein (SFP) expression of male Drosophila melanogaster paired with highly receptive virgin females in non-competitive settings. Depending on sex and dose, there was a 3-6-day incubation period after infection, followed by an abrupt onset of mortality. Meanwhile, the immune response was strongly induced already 38 h after infection and continued to increase as infection progressed. Latency to mate somewhat increased during the incubation period compared to sham-treated males, but even on Day 5 post infection >90% of infected males mated within 2 h. During the incubation period, M. brunneum infection reduced male reproductive potential (the number of offspring sired without mate limitation) by 11%, with no clear increase over time. Approaching the end of the incubation period, infected males had lower ability to convert number of mating opportunities into number of offspring. After repeated mating, infected males had lower SFP expression than sham controls, more so in males that mated with few mates 24 h earlier. Overall, despite strong activation of the immune response, males' mating ability and fertility remained surprisingly little affected by the fungal infection, even shortly before the onset of mortality. This suggests that the selection for resistance acts mainly through mortality, and the scope for fertility selection to enhance resistance in non-competing settings is rather limited.
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Affiliation(s)
- Aijuan Liao
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Fanny Cavigliasso
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Loriane Savary
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Tadeusz J. Kawecki
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
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4
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Rodgers ML, Bolnick DI. Opening a can of worms: a test of the co-infection facilitation hypothesis. Oecologia 2024; 204:317-325. [PMID: 37386196 PMCID: PMC10756930 DOI: 10.1007/s00442-023-05409-7] [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: 03/17/2022] [Accepted: 06/12/2023] [Indexed: 07/01/2023]
Abstract
Parasitic infections are a global occurrence and impact the health of many species. Coinfections, where two or more species of parasite are present in a host, are a common phenomenon across species. Coinfecting parasites can interact directly or indirectly via their manipulation of (and susceptibility to) the immune system of their shared host. Helminths, such as the cestode Schistocephalus solidus, are well known to suppress immunity of their host (threespine stickleback, Gasterosteus aculeatus), potentially facilitating other parasite species. Yet, hosts can evolve a more robust immune response (as seen in some stickleback populations), potentially turning facilitation into inhibition. Using wild-caught stickleback from 20 populations with non-zero S. solidus prevalence, we tested an a priori hypothesis that S. solidus infection facilitates infection by other parasites. Consistent with this hypothesis, individuals with S. solidus infections have 18.6% higher richness of other parasites compared to S. solidus-uninfected individuals from the same lakes. This facilitation-like trend is stronger in lakes where S. solidus is particularly successful but is reversed in lakes with sparse and smaller cestodes (indicative of stronger host immunity). These results suggest that a geographic mosaic of host-parasite co-evolution might lead to a mosaic of between-parasite facilitation/inhibition effects.
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Affiliation(s)
- Maria L Rodgers
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA.
- Department of Biological Sciences, North Carolina State University, Morehead City, NC, 28557, USA.
| | - Daniel I Bolnick
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA
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5
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Matthews DG, Maciejewski MF, Wong GA, Lauder GV, Bolnick DI. Locomotor effects of a fibrosis-based immune response in stickleback fish. J Exp Biol 2023; 226:jeb246684. [PMID: 37947155 DOI: 10.1242/jeb.246684] [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: 08/30/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023]
Abstract
The vertebrate immune system provides an impressively effective defense against parasites and pathogens. However, these benefits must be balanced against a range of costly side-effects including energy loss and risks of auto-immunity. These costs might include biomechanical impairment of movement, but little is known about the intersection between immunity and biomechanics. Here, we show that a fibrosis immune response to Schistocephalus solidus infection in freshwater threespine stickleback (Gasterosteus aculeatus) has collateral effects on their locomotion. Although fibrosis is effective at reducing infection, some populations of stickleback actively suppress this immune response, possibly because the costs of fibrosis outweigh the benefits. We quantified the locomotor effects of the fibrosis immune response in the absence of parasites to investigate whether there are incidental costs of fibrosis that could help explain why some fish forego this effective defense. To do this, we induced fibrosis in stickleback and then tested their C-start escape performance. Additionally, we measured the severity of fibrosis, body stiffness and body curvature during the escape response. We were able to estimate performance costs of fibrosis by including these variables as intermediates in a structural equation model. This model revealed that among control fish without fibrosis, there is a performance cost associated with increased body stiffness. However, fish with fibrosis did not experience this cost but rather displayed increased performance with higher fibrosis severity. This result demonstrates that the adaptive landscape of immune responses can be complex with the potential for wide-reaching and unexpected fitness consequences.
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Affiliation(s)
- David G Matthews
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| | - Meghan F Maciejewski
- Department of Evolution, Ecology, and Behavior, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Greta A Wong
- Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| | - George V Lauder
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| | - Daniel I Bolnick
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
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6
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Matthews DG, Maciejewski MF, Wong GA, Lauder GV, Bolnick DI. Locomotor effects of a fibrosis-based immune response in stickleback fish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.24.546342. [PMID: 37425734 PMCID: PMC10326981 DOI: 10.1101/2023.06.24.546342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The vertebrate immune system provides an impressively effective defense against parasites and pathogens. However, these benefits must be balanced against a range of costly side-effects including energy loss and risks of auto-immunity. These costs might include biomechanical impairment of movement, but little is known about the intersection between immunity and biomechanics. Here, we show that a fibrosis immune response in threespine stickleback (Gasterosteus aculeatus) has collateral effects on their locomotion. When freshwater stickleback are infected with the tapeworm parasite Schistocephalus solidus, they face an array of fitness consequences ranging from impaired body condition and fertility to an increased risk of mortality. To fight the infection, some stickleback will initiate a fibrosis immune response in which they produce excess collagenous tissue in their coelom. Although fibrosis is effective at reducing infection, some populations of stickleback actively suppress this immune response, possibly because the costs of fibrosis outweigh the benefits. Here we quantify the locomotor effects of the fibrosis immune response in the absence of parasites to investigate whether there are collateral costs of fibrosis that could help explain why some fish forego this effective defense. To do this, we induce fibrosis in stickleback and then test their C-start escape performance. Additionally, we measure the severity of fibrosis, body stiffness, and body curvature during the escape response. We were able to estimate performance costs of fibrosis by including these variables as intermediates in a structural equation model. This model reveals that among control fish without fibrosis, there is a performance cost associated with increased body stiffness. However, fish with fibrosis did not experience this cost but rather displayed increased performance with higher fibrosis severity. This result demonstrates that the adaptive landscape of immune responses can be complex with the potential for wide reaching and unexpected fitness consequences.
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Affiliation(s)
- David G. Matthews
- Organismic and Evolutionary Biology, Harvard University, Cambridge, 02138, MA, USA
- Museum of Comparative Zoology, Harvard University, Cambridge, 02138, MA, USA
| | - Meghan F. Maciejewski
- Department of Evolution, Ecology, and Behavior, University of Illinois at Urbana-Champaign, Champaign, 61820, IL, USA
- Department of Ecology Evolutionary Biology, University of Connecticut, Storrs, 06269, CT, USA
| | - Greta A. Wong
- Museum of Comparative Zoology, Harvard University, Cambridge, 02138, MA, USA
| | - George V. Lauder
- Organismic and Evolutionary Biology, Harvard University, Cambridge, 02138, MA, USA
- Museum of Comparative Zoology, Harvard University, Cambridge, 02138, MA, USA
| | - Daniel I. Bolnick
- Department of Ecology Evolutionary Biology, University of Connecticut, Storrs, 06269, CT, USA
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7
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Weber JN, Steinel NC, Peng F, Shim KC, Lohman BK, Fuess LE, Subramanian S, Lisle SPD, Bolnick DI. Evolutionary gain and loss of a pathological immune response to parasitism. Science 2022; 377:1206-1211. [PMID: 36074841 PMCID: PMC9869647 DOI: 10.1126/science.abo3411] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Parasites impose fitness costs on their hosts. Biologists often assume that natural selection favors infection-resistant hosts. Yet, when the immune response itself is costly, theory suggests that selection may sometimes favor loss of resistance, which may result in alternative stable states where some populations are resistant and others are tolerant. Intraspecific variation in immune costs is rarely surveyed in a manner that tests evolutionary patterns, and there are few examples of adaptive loss of resistance. Here, we show that when marine threespine stickleback colonized freshwater lakes, they gained resistance to the freshwater-associated cestode Schistocephalus solidus. Extensive peritoneal fibrosis and inflammation are a commonly observed phenotype that contributes to suppression of cestode growth and viability but also imposes a substantial cost on fecundity. Combining genetic mapping and population genomics, we find that opposing selection generates immune system differences between tolerant and resistant populations, consistent with divergent optimization.
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Affiliation(s)
- Jesse N Weber
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Natalie C Steinel
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Foen Peng
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Kum Chuan Shim
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Brian K Lohman
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Lauren E Fuess
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Swapna Subramanian
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Stephen P De Lisle
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Daniel I Bolnick
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA.,Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
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8
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Hund AK, Fuess LE, Kenney ML, Maciejewski MF, Marini JM, Shim KC, Bolnick DI. Population-level variation in parasite resistance due to differences in immune initiation and rate of response. Evol Lett 2022; 6:162-177. [PMID: 35386836 PMCID: PMC8966477 DOI: 10.1002/evl3.274] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 01/20/2023] Open
Abstract
Closely related populations often differ in resistance to a given parasite, as measured by infection success or failure. Yet, the immunological mechanisms of these evolved differences are rarely specified. Does resistance evolve via changes to the host's ability to recognize that an infection exists, actuate an effective immune response, or attenuate that response? We tested whether each of these phases of the host response contributed to threespine sticklebacks' recently evolved resistance to their tapeworm Schistocephalus solidus. Although marine stickleback and some susceptible lake fish permit fast-growing tapeworms, other lake populations are resistant and suppress tapeworm growth via a fibrosis response. We subjected lab-raised fish from three populations (susceptible marine "ancestors," a susceptible lake population, and a resistant lake population) to a novel immune challenge using an injection of (1) a saline control, (2) alum, a generalized pro-inflammatory adjuvant that causes fibrosis, (3) a tapeworm protein extract, or (4) a combination of alum and tapeworm protein. With enough time, all three populations generated a robust fibrosis response to the alum treatments. Yet, only the resistant population exhibited a fibrosis response to the tapeworm protein alone. Thus, these populations differed in their ability to respond to the tapeworm protein but shared an intact fibrosis pathway. The resistant population also initiated fibrosis faster in response to alum, and was able to attenuate fibrosis, unlike the susceptible populations' slow but longer lasting response to alum. As fibrosis has pathological side effects that reduce fecundity, the faster recovery by the resistant population may reflect an adaptation to mitigate the costs of immunity. Broadly, our results confirm that parasite detection and immune initiation, activation speed, and immune attenuation simultaneously contribute to the evolution of parasite resistance and adaptations to infection in natural populations.
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Affiliation(s)
- Amanda K. Hund
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesota55123
| | - Lauren E. Fuess
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticut06269
- Current Address: Department of BiologyTexas State UniversitySan MarcosTexas78666
| | - Mariah L. Kenney
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticut06269
| | - Meghan F. Maciejewski
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticut06269
| | - Joseph M. Marini
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticut06269
| | - Kum Chuan Shim
- Department of Ecology, Evolution, and BehaviorUniversity of Texas at AustinAustinTexas78712
| | - Daniel I. Bolnick
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticut06269
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9
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Fernandez Begne P. Digest: No conflict of interest between the sexes for optimal immune response in threespine stickleback . Evolution 2021; 75:2618-2619. [PMID: 34423439 DOI: 10.1111/evo.14332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/17/2021] [Indexed: 11/30/2022]
Abstract
Will sex-specificparasite exposure lead to sexually antagonistic immune trait fitness optima? Despite female stickleback encountering parasites at a higher rate, De Lisle and Bolnick found no evidence of sexual conflict related to their primary immune trait. Both male and female fish suffered high costs of infection and immune response on reproduction. If costs of both immunity and infection are high and concordant, the sexual conflict will not arise despite different parasite exposure rates.
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10
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Vrtílek M, Bolnick DI. Macroevolutionary foundations of a recently evolved innate immune defense. Evolution 2021; 75:2600-2612. [PMID: 34347301 PMCID: PMC8488947 DOI: 10.1111/evo.14316] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/06/2021] [Accepted: 07/20/2021] [Indexed: 01/13/2023]
Abstract
Antagonistic interactions between hosts and parasites may drive the evolution of novel host defenses, or new parasite strategies. Host immunity is therefore one of the fastest evolving traits. But where do the novel immune traits come from? Here, we test for phylogenetic conservation in a rapidly evolving immune trait—peritoneal fibrosis. Peritoneal fibrosis is a costly defense against a specialist tapeworm, Schistocephalus solidus (Cestoda), expressed in some freshwater populations of threespine stickleback fish (Gasterosteus aculeatus, Perciformes). We asked whether stickleback fibrosis is a derived species‐specific trait or an ancestral immune response that was widely distributed across ray‐finned fish (Actinopterygii) only to be employed by threespine stickleback against the specialist parasite. We combined literature review on peritoneal fibrosis with a comparative experiment using either parasite‐specific, or nonspecific, immune challenge in deliberately selected species across fish tree of life. We show that ray‐finned fish are broadly, but not universally, able to induce peritoneal fibrosis when challenged with a generic stimulus (Alum adjuvant). The experimental species were, however, largely indifferent to the tapeworm antigen homogenate. Peritoneal fibrosis, thus, appears to be a common and deeply conserved fish immune response that was co‐opted by stickleback to adapt to a new selective challenge.
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Affiliation(s)
- Milan Vrtílek
- Institute of Vertebrate Biology, The Czech Academy of Sciences, Brno, 603 65, Czech Republic
| | - Daniel I Bolnick
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, 06269
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