1
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Sauer EL, Venesky MD, McMahon TA, Cohen JM, Bessler S, Brannelly LA, Brem F, Byrne AQ, Halstead N, Hyman O, Johnson PTJ, Richards-Zawacki CL, Rumschlag SL, Sears B, Rohr JR. Are novel or locally adapted pathogens more devastating and why? Resolving opposing hypotheses. Ecol Lett 2024; 27:e14431. [PMID: 38712705 DOI: 10.1111/ele.14431] [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: 06/13/2023] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 05/08/2024]
Abstract
There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, using Batrachochytrium dendrobatidis, the fungus associated with worldwide amphibian declines, we test the hypothesis that there is enough variance in "novel" (quantified by geographic and phylogenetic distance) host-pathogen outcomes to pose substantial risk of pathogen introductions despite local adaptation being common. Our continental-scale common garden experiment and global-scale meta-analysis demonstrate that local amphibian-fungal interactions result in higher pathogen prevalence, pathogen growth, and host mortality, but novel interactions led to variable consequences with especially virulent host-pathogen combinations still occurring. Thus, while most pathogen introductions are benign, enough variance exists in novel host-pathogen outcomes that moving organisms around the planet greatly increases the chance of pathogen introductions causing profound harm.
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Affiliation(s)
- Erin L Sauer
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Matthew D Venesky
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Biology, Allegheny College, Meadville, Pennsylvania, USA
| | - Taegan A McMahon
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Biology Department, Connecticut College, New London, Connecticut, USA
| | - Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
| | - Scott Bessler
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Laura A Brannelly
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USA
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Forrest Brem
- Biology Department, University of Memphis, Memphis, Tennessee, USA
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
| | - Neal Halstead
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Wildlands Conservation, Tampa, Florida, USA
| | - Oliver Hyman
- Biology Department, James Madison University, Harrisonburg, Virginia, USA
| | - Pieter T J Johnson
- Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | - Corinne L Richards-Zawacki
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Samantha L Rumschlag
- Department of Biology, Miami University, Oxford, Ohio, USA
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota, USA
| | - Brittany Sears
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
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2
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Fleischer R, Eibner GJ, Schwensow NI, Pirzer F, Paraskevopoulou S, Mayer G, Corman VM, Drosten C, Wilhelm K, Heni AC, Sommer S, Schmid DW. Immunogenetic-pathogen networks shrink in Tome's spiny rat, a generalist rodent inhabiting disturbed landscapes. Commun Biol 2024; 7:169. [PMID: 38341501 PMCID: PMC10858909 DOI: 10.1038/s42003-024-05870-x] [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: 03/10/2023] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Anthropogenic disturbance may increase the emergence of zoonoses. Especially generalists that cope with disturbance and live in close contact with humans and livestock may become reservoirs of zoonotic pathogens. Yet, whether anthropogenic disturbance modifies host-pathogen co-evolutionary relationships in generalists is unknown. We assessed pathogen diversity, neutral genome-wide diversity (SNPs) and adaptive MHC class II diversity in a rodent generalist inhabiting three lowland rainforest landscapes with varying anthropogenic disturbance, and determined which MHC alleles co-occurred more frequently with 13 gastrointestinal nematodes, blood trypanosomes, and four viruses. Pathogen-specific selection pressures varied between landscapes. Genome-wide diversity declined with the degree of disturbance, while MHC diversity was only reduced in the most disturbed landscape. Furthermore, pristine forest landscapes had more functional important MHC-pathogen associations when compared to disturbed forests. We show co-evolutionary links between host and pathogens impoverished in human-disturbed landscapes. This underscores that parasite-mediated selection might change even in generalist species following human disturbance which in turn may facilitate host switching and the emergence of zoonoses.
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Affiliation(s)
- Ramona Fleischer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Georg Joachim Eibner
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
- Institute of Virology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nina Isabell Schwensow
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Fabian Pirzer
- Institute of Virology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Gerd Mayer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Victor Max Corman
- Institute of Virology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Robert Koch Institute, Nordufer 20, Berlin, 13353, Germany
| | - Christian Drosten
- Institute of Virology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Robert Koch Institute, Nordufer 20, Berlin, 13353, Germany
- German Centre for Infection Research (DZIF), Berlin, Germany
| | - Kerstin Wilhelm
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Alexander Christoph Heni
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.
| | - Dominik Werner Schmid
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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3
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Ali HAA, Coulson T, Clegg SM, Quilodrán CS. The effect of divergent and parallel selection on the genomic landscape of divergence. Mol Ecol 2024; 33:e17225. [PMID: 38063473 DOI: 10.1111/mec.17225] [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: 07/19/2023] [Revised: 10/25/2023] [Accepted: 11/16/2023] [Indexed: 01/25/2024]
Abstract
While the role of selection in divergence along the speciation continuum is theoretically well understood, defining specific signatures of selection in the genomic landscape of divergence is empirically challenging. Modelling approaches can provide insight into the potential role of selection on the emergence of a heterogenous genomic landscape of divergence. Here, we extend and apply an individual-based approach that simulates the phenotypic and genotypic distributions of two populations under a variety of selection regimes, genotype-phenotype maps, modes of migration, and genotype-environment interactions. We show that genomic islands of high differentiation and genomic valleys of similarity may respectively form under divergent and parallel selection between populations. For both types of between-population selection, negative and positive frequency-dependent selection within populations generated genomic islands of higher magnitude and genomic valleys of similarity, respectively. Divergence rates decreased under strong dominance with divergent selection, as well as in models including genotype-environment interactions under parallel selection. For both divergent and parallel selection models, divergence rate was higher under an intermittent migration regime between populations, in contrast to a constant level of migration across generations, despite an equal number of total migrants. We highlight that interpreting a particular evolutionary history from an observed genomic pattern must be done cautiously, as similar patterns may be obtained from different combinations of evolutionary processes. Modelling approaches such as ours provide an opportunity to narrow the potential routes that generate the genomic patterns of specific evolutionary histories.
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Affiliation(s)
- Hisham A A Ali
- Department of Biology, Edward Grey Institute of Field Ornithology, University of Oxford, Oxford, UK
| | - Tim Coulson
- Department of Biology, Edward Grey Institute of Field Ornithology, University of Oxford, Oxford, UK
| | - Sonya M Clegg
- Department of Biology, Edward Grey Institute of Field Ornithology, University of Oxford, Oxford, UK
| | - Claudio S Quilodrán
- Department of Biology, Edward Grey Institute of Field Ornithology, University of Oxford, Oxford, UK
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland
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4
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Schmid M, Rueffler C, Lehmann L, Mullon C. Resource Variation Within and Between Patches: Where Exploitation Competition, Local Adaptation, and Kin Selection Meet. Am Nat 2024; 203:E19-E34. [PMID: 38207145 DOI: 10.1086/727483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
AbstractIn patch- or habitat-structured populations, different processes can favor adaptive polymorphism at different scales. While spatial heterogeneity can generate spatially disruptive selection favoring variation between patches, local competition can lead to locally disruptive selection promoting variation within patches. So far, almost all theory has studied these two processes in isolation. Here, we use mathematical modeling to investigate how resource variation within and between habitats influences the evolution of variation in a consumer population where individuals compete in finite patches connected by dispersal. We find that locally and spatially disruptive selection typically act in concert, favoring polymorphism under a wider range of conditions than when in isolation. But when patches are small and dispersal between them is low, kin competition inhibits the emergence of polymorphism, especially when the latter is driven by local competition for resources. We further use our model to clarify what comparisons between trait and neutral genetic differentiation (Q ST / F ST comparisons) can tell about the nature of selection. Overall, our results help us understand the interaction between two major drivers of polymorphism: locally and spatially disruptive selection, and how this interaction is modulated by the unavoidable effects of kin selection under limited dispersal.
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5
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Lenz TL. HLA Genes: A Hallmark of Functional Genetic Variation and Complex Evolution. Methods Mol Biol 2024; 2809:1-18. [PMID: 38907887 DOI: 10.1007/978-1-0716-3874-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2024]
Abstract
The major histocompatibility complex (MHC) with its highly polymorphic HLA genes represents one of the most intensely studied genomic regions in the genome. MHC proteins play a key role in antigen-specific immunity and are associated with a wide range of complex diseases. Despite decades of research and many advances in the field, the characterization and interpretation of its genetic and genomic variability remain challenging. Here an overview is provided of the MHC, the nature of its exceptional variability, and the complex evolutionary processes assumed to drive this variability. Highlighted are also recent advances in the field that promise to improve our understanding of the variability in the MHC and in antigen-specific immunity more generally.
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Affiliation(s)
- Tobias L Lenz
- Research Unit for Evolutionary Immunogenomics, Department of Biology, University of Hamburg, Hamburg, Germany.
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6
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Gowane GR, Sharma P, Kumar R, Misra SS, Alex R, Vohra V, Chhotaray S, Dass G, Chopra A, Kandalkar Y, Vijay V, Choudhary A, Magotra A, Rajendran R. Cross-population genetic analysis revealed genetic variation and selection in the Ovar-DRB1 gene of Indian sheep breeds. Anim Biotechnol 2023; 34:2928-2939. [PMID: 36153754 DOI: 10.1080/10495398.2022.2125404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
In sheep, MHC variability is studied widely to explore disease association. The aim of the current study was to explore the genetic diversity of Ovar-DRB diversity across sheep breeds of India. Here, Ovar-DRB1 locus was studied across 20 sheep breeds. DRB1 was amplified (301 bp) and sequenced using a PCR-sequence-based typing approach. Results revealed a high degree of heterozygosity across breeds (mean: 73.99%). Overall mean distance for DRB1 was highest in Sangamneri (0.18) and lowest in Madgyal sheep (0.10). There was a higher rate of transition, across breeds. Further, 39 alleles were isolated in different breeds, out of which 10 were new. To allow easy access and use of the immune-polymorphic database, an online database management system was launched (http://www.mhcdbms.in/). Nucleotide content across breeds for the DRB1 region revealed the richness of GC content (59.26%). Wu-Kabat index revealed vast genetic variation across peptide binding sites (PBS) of DRB1. Residues 6, 66, 69, 52, and 81, were polymorphic showing utility for antigen presentation. All breeds were under positive selection for DRB1 locus (dN > dS). Study revealed the importance of DRB locus diversity for beta chain specifically at PBS across sheep breeds of the Indian subcontinent and presented evidence of positive selection for DRB owing to its evolutionary significance.
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Affiliation(s)
- G R Gowane
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Priya Sharma
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Rajiv Kumar
- Animal Genetics & Breeding Division, ICAR-Central Sheep & Wool Research Institute, Avikanagar, India
| | - S S Misra
- Animal Genetics & Breeding Division, ICAR-Central Sheep & Wool Research Institute, Avikanagar, India
| | - Rani Alex
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - V Vohra
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - S Chhotaray
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Gopal Dass
- Animal Genetics & Breeding Division, ICAR-Central Institute for Research on Goats, Makhdoom, India
| | - Ashish Chopra
- Animal Genetics & Breeding Division, ICAR-Arid Region Campus, Central Sheep & Wool Research Institute Bikaner, Avikanagar, India
| | - Yogesh Kandalkar
- Deccani Sheep Breeding Unit, NWPSI at Mahatma Phule Krishi Vidyapith, Rahuri, India
| | - V Vijay
- Sonadi Seep Breeding Unit, NWPSI at Navaniya Maharana Pratap University of Agriculture and Technology, Udaipur, India
| | | | - Ankit Magotra
- Animal Genetics & Breeding Division, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India
| | - R Rajendran
- Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Theni, India
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7
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Christie MR, McNickle GG. Negative frequency dependent selection unites ecology and evolution. Ecol Evol 2023; 13:e10327. [PMID: 37484931 PMCID: PMC10361363 DOI: 10.1002/ece3.10327] [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: 06/02/2023] [Accepted: 07/07/2023] [Indexed: 07/25/2023] Open
Abstract
From genes to communities, understanding how diversity is maintained remains a fundamental question in biology. One challenging to identify, yet potentially ubiquitous, mechanism for the maintenance of diversity is negative frequency dependent selection (NFDS), which occurs when entities (e.g., genotypes, life history strategies, species) experience a per capita reduction in fitness with increases in relative abundance. Because NFDS allows rare entities to increase in frequency while preventing abundant entities from excluding others, we posit that negative frequency dependent selection plays a central role in the maintenance of diversity. In this review, we relate NFDS to coexistence, identify mechanisms of NFDS (e.g., mutualism, predation, parasitism), review strategies for identifying NFDS, and distinguish NFDS from other mechanisms of coexistence (e.g., storage effects, fluctuating selection). We also emphasize that NFDS is a key place where ecology and evolution intersect. Specifically, there are many examples of frequency dependent processes in ecology, but fewer cases that link this process to selection. Similarly, there are many examples of selection in evolution, but fewer cases that link changes in trait values to negative frequency dependence. Bridging these two well-developed fields of ecology and evolution will allow for mechanistic insights into the maintenance of diversity at multiple levels.
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Affiliation(s)
- Mark R. Christie
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
- Department of Forestry and Natural ResourcesPurdue UniversityWest LafayetteIndianaUSA
| | - Gordon G. McNickle
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
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8
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Bolnick DI, Arruda S, Polania C, Simonse L, Padhiar A, Roth A, Rodgers ML. The dominance of coinfecting parasites' indirect effects on host traits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.12.528182. [PMID: 36798170 PMCID: PMC9934634 DOI: 10.1101/2023.02.12.528182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Indirect genetic effects (IGEs) exist when there is heritable variation in one species' ability to alter a second species' traits. For example, parasites can evolve disparate strategies to manipulate host immune response, whether by evading detection or suppressing immunity. A complication arises during coinfection, when two or more parasite genotypes may try to impose distinct IGEs on the same host trait: which parasite's IGE will be dominant? Here, we apply the notion of dominance to IGEs during coinfection. Using a mathematical model we show that the dominance of IGEs can alter the evolutionary dynamics of parasites. We consider a resident parasite population receiving rare immigrants with a different immune manipulation trait. These immigrants' relative fitness depends on resident prevalence (e.g., the probability immigrants are alone in a host, or coinfecting with a native), and the dominance of the immigrant's IGE on host immunity. Next, we show experimentally that the cestode Schistocephalus solidus exerts an IGE on a host immune trait: parasite antigens from different populations produced different intensities of fibrosis. We then evaluated IGE dominance, finding evidence for overdominance (coinjected antigens induced an even stronger host immune response) which would be detrimental to immigrants when resident prevalence is high. This combination of experimental and modeling results shows that parasites do exhibit IGEs on host traits, and that the dominance of these IGEs during coinfection can substantially alter parasite evolution.
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Affiliation(s)
- Daniel I. Bolnick
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Sophia Arruda
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Christian Polania
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Lauren Simonse
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Arshad Padhiar
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Andrea Roth
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
| | - Maria L. Rodgers
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs CT 06269, USA
- Present address: Department of Biological Sciences, North Carolina State University, Morehead City NC 28557, USA
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9
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Gompert Z, Flaxman SM, Feder JL, Chevin LM, Nosil P. Laplace's demon in biology: Models of evolutionary prediction. Evolution 2022; 76:2794-2810. [PMID: 36193839 DOI: 10.1111/evo.14628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 08/23/2022] [Accepted: 08/30/2022] [Indexed: 01/22/2023]
Abstract
Our ability to predict natural phenomena can be limited by incomplete information. This issue is exemplified by "Laplace's demon," an imaginary creature proposed in the 18th century, who knew everything about everything, and thus could predict the full nature of the universe forward or backward in time. Quantum mechanics, among other things, has cast doubt on the possibility of Laplace's demon in the full sense, but the idea still serves as a useful metaphor for thinking about the extent to which prediction is limited by incomplete information on deterministic processes versus random factors. Here, we use simple analytical models and computer simulations to illustrate how data limits can be captured in a Bayesian framework, and how they influence our ability to predict evolution. We show how uncertainty in measurements of natural selection, or low predictability of external environmental factors affecting selection, can greatly reduce predictive power, often swamping the influence of intrinsic randomness caused by genetic drift. Thus, more accurate knowledge concerning the causes and action of natural selection is key to improving prediction. Fortunately, our analyses and simulations show quantitatively that reasonable improvements in data quantity and quality can meaningfully increase predictability.
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Affiliation(s)
| | | | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Luis-Miguel Chevin
- CEFE, Univ Montpellier, Montpellier, France.,CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Patrik Nosil
- CEFE, Univ Montpellier, Montpellier, France.,CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
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10
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Jenck CS, Lehto WR, Hunnicutt KE, Murphy SM, Quinn TW, Larson EL, Tinghitella RM. Genetic divergence among threespine stickleback that differ in nuptial coloration. J Evol Biol 2022; 35:934-947. [PMID: 35716364 DOI: 10.1111/jeb.14035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/11/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022]
Abstract
Sexual signals are shaped by their intended and unintended receivers as well as the signalling environment. This interplay between sexual and natural selection can lead to divergence in signals in heterogeneous environments. Yet, the extent to which gene flow is restricted when signalling phenotypes vary across environments and over what spatial scales remains an outstanding question. In this study, we quantify gene flow between two colour morphs, red and black, of freshwater threespine stickleback fish (Gasterosteus aculeatus). We capitalize on the very recent divergence of signalling phenotypes in this system to characterize within-species and among-morph genetic variation and to test for levels of gene flow between colour morphs in Oregon and Washington. Despite limited evidence for assortative mating between allopatric red and black populations, we found that black populations are genetically distinct from nearby red populations and that the black morph appears to have evolved independently at least twice in Oregon and Washington. Surprisingly, we uncovered a group of stickleback in one small coastal stream, Connor Creek, which is genetically and morphologically distinct from the red and black colour morphs and from marine stickleback. Historically, both colour morphs have coexisted in this location and sometimes hybridized, raising new questions about the origins and history of these fish, which were first described as anadromous-black hybrids >50 years ago. Understanding how genetic variation is currently partitioned within and among populations and colour morphs in this system should prompt future studies to assess the relative roles of habitat, ecological and pre- and post-reproductive barriers in the genetic divergence and phenotypic patterns we observe in nature.
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Affiliation(s)
- Clara S Jenck
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Whitley R Lehto
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Kelsie E Hunnicutt
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Shannon M Murphy
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Thomas W Quinn
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Erica L Larson
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Robin M Tinghitella
- Department of Biological Sciences, University of Denver, Denver, Colorado, USA
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11
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Migalska M, Przesmycka K, Alsarraf M, Bajer A, Behnke-Borowczyk J, Grzybek M, Behnke JM, Radwan J. Long term patterns of association between MHC and helminth burdens in the bank vole support Red Queen dynamics. Mol Ecol 2022; 31:3400-3415. [PMID: 35510766 PMCID: PMC9325469 DOI: 10.1111/mec.16486] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 11/28/2022]
Abstract
Major histocompatibility complex (MHC) genes encode proteins crucial for adaptive immunity of vertebrates. Negative frequency-dependent selection (NFDS), resulting from adaptation of parasites to common MHC types, has been hypothesized to maintain high, functionally relevant polymorphism of MHC, but demonstration of this relationship has remained elusive. In particular, differentiation of NFDS from fluctuating selection, resulting from changes in parasite communities in time and space (FS), has proved difficult in short-term studies. Here, we used temporal data, accumulated through long-term monitoring of helminths infecting bank voles (Myodes glareolus), to test specific predictions of NFDS on MHC class II. Data were collected in three, moderately genetically differentiated subpopulations in Poland, which were characterized by some stable spatiotemporal helminth communities but also events indicating introduction of new species and loss of others. We found a complex association between individual MHC diversity and species richness, where intermediate numbers of DRB supertypes correlated with lowest species richness, but the opposite was true for DQB supertypes - arguing against universal selection for immunogenetic optimality. We also showed that particular MHC supertypes explain a portion of the variance in prevalence and abundance of helminths, but this effect was subpopulation-specific, which is consistent with both NFDS and FS. Finally, in line with NFDS, we found that certain helminths that have recently colonized or spread in a given subpopulation, more frequently or intensely infected voles with MHC supertypes that have been common in the recent past. Overall, our results highlight complex spatial and temporal patterns of MHC-parasite associations, the latter being consistent with Red Queen coevolutionary dynamics.
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Affiliation(s)
- Magdalena Migalska
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland
| | - Karolina Przesmycka
- Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Mohammed Alsarraf
- Department of Eco-epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Anna Bajer
- Department of Eco-epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Jolanta Behnke-Borowczyk
- Department of Forest Entomology and Pathology, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 71c, 60-625, Poznań, Poland
| | - Maciej Grzybek
- Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Powstania Styczniowego 9B, 81-429, Gdynia, Poland
| | - Jerzy M Behnke
- School of Life Science, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Jacek Radwan
- Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
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12
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Fleischer R, Schmid DW, Uddin W, Brändel SD, Rasche A, Corman VM, Drosten C, Tschapka M, Sommer S. Interaction between MHC diversity and constitution, gut microbiota and Astrovirus infections in a neotropical bat. Mol Ecol 2022; 31:3342-3359. [PMID: 35510794 DOI: 10.1111/mec.16491] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/28/2022]
Abstract
Astroviruses (AstVs) infect numerous mammalian species including reservoirs such as bats. Peptides encoded by the genes of the highly polymorphic Major Histocompatibility Complex (MHC) form the first line of host defence against pathogens. Aside from direct involvement in mounting adaptive immune responses, MHC class II genes are hypothesized to regulate gut commensal diversity and shape the production of immune-modulatory substances by microbes, indirectly affecting host susceptibility. Despite initial empirical evidence for the link between host MHC and the microbiota, associations among these factors remain largely unknown. To fill this gap, we examined MHC allelic diversity and constitution, the gut bacterial community and abundance pattern of a wild population of the neotropical bat (Artibeus jamaicensis) challenged by AstV infections. First, we show an age-dependent relationship between the host MHC class II diversity and constitution and the gut microbiota in AstV uninfected bats. Crucially, these associations changed in AstV infected bats. Additionally, we identify changes in abundance of specific bacterial taxa linked to the presence of certain MHC supertypes and AstV infection. We suggest changes in the microbiota to be either a result of AstV infection or the MHC-mediated modulation of microbial communities. The latter could subsequently affect microbe-mediated immunity and resistance against AstV infection. Our results underscore that the reciprocal nature of host immune genetics, gut microbial diversity and pathogen infection requires attention, which is particularly important given its repercussions for disease susceptibility and severity in wild animal populations with a history of zoonotic spillover and frequent human contact.
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Affiliation(s)
- Ramona Fleischer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Dominik Werner Schmid
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Wasim Uddin
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Stefan Dominik Brändel
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.,Smithsonian Tropical Research Institute, Ancon, Panama
| | - Andrea Rasche
- Smithsonian Tropical Research Institute, Ancon, Panama.,Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany
| | - Victor M Corman
- Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany.,German Centre for Infection Research (DZIF), associated partner Charité, Chariteplatz 1, 10117, Berlin, Germany
| | - Christian Drosten
- Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany.,German Centre for Infection Research (DZIF), associated partner Charité, Chariteplatz 1, 10117, Berlin, Germany
| | - Marco Tschapka
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.,Smithsonian Tropical Research Institute, Ancon, Panama
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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13
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Blain SA, Chavarie L, Kinney MH, Schluter D. A test of frequency‐dependent selection in the evolution of a generalist phenotype. Ecol Evol 2022; 12:e8831. [PMID: 35432932 PMCID: PMC9006234 DOI: 10.1002/ece3.8831] [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: 09/28/2021] [Revised: 01/30/2022] [Accepted: 02/04/2022] [Indexed: 11/14/2022] Open
Abstract
A solitary population of consumers frequently evolves to the middle of a resource gradient and an intermediate mean phenotype compared to a sympatric pair of competing species that diverge to either side via character displacement. The forces governing the distribution of phenotypes in these allopatric populations, however, are little investigated. Theory predicts that the intermediate mean phenotype of the generalist should be maintained by negative frequency‐dependent selection, whereby alternate extreme phenotypes are favored because they experience reduced competition for resources when rare. However, the theory makes assumptions that are not always met, and alternative explanations for an intermediate phenotype are possible. We provide a test of this prediction in a mesocosm experiment using threespine stickleback that are ecologically and phenotypically intermediate between the more specialized stickleback species that occur in pairs. We manipulated the frequency distribution of phenotypes in two treatments and then measured effects on a focal intermediate population. We found a slight frequency‐dependent effect on survival in the predicted direction but not on individual growth rates. This result suggests that frequency‐dependent selection might be a relatively weak force across the range of phenotypes within an intermediate population and we suggest several general reasons why this might be so. We propose that allopatric populations might often be maintained at an intermediate phenotype instead by stabilizing or fluctuating directional selection.
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Affiliation(s)
- Stephanie A. Blain
- Department of Zoology and Biodiversity Research Center University of British Columbia Vancouver British Columbia Canada
| | - Louise Chavarie
- Department of Zoology and Biodiversity Research Center University of British Columbia Vancouver British Columbia Canada
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
| | - Mackenzie H. Kinney
- Department of Zoology and Biodiversity Research Center University of British Columbia Vancouver British Columbia Canada
| | - Dolph Schluter
- Department of Zoology and Biodiversity Research Center University of British Columbia Vancouver British Columbia Canada
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14
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Huang W, Dicks KL, Hadfield JD, Johnston SE, Ballingall KT, Pemberton JM. Contemporary selection on MHC genes in a free-living ruminant population. Ecol Lett 2022; 25:828-838. [PMID: 35050541 PMCID: PMC9306867 DOI: 10.1111/ele.13957] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/21/2021] [Accepted: 12/08/2021] [Indexed: 11/27/2022]
Abstract
Genes within the major histocompatibility complex (MHC) are the most variable identified in vertebrates. Pathogen-mediated selection is believed to be the main force maintaining MHC diversity. However, relatively few studies have demonstrated contemporary selection on MHC genes. Here, we examine associations between MHC variation and several fitness measurements including total fitness and five fitness components, in 3400 wild Soay sheep (Ovis aries) monitored between 1989 and 2012. In terms of total fitness, measured as lifetime breeding success of all individuals born, we found haplotypes named C and D were associated with decreased and increased male total fitness respectively. In terms of fitness components, juvenile survival was associated with haplotype divergence while individual haplotypes (C, D and F) were associated with adult fitness components. Consistent with the increased male total fitness, the rarest haplotype D has increased in frequency throughout the study period more than expected under neutral expectations. Our results demonstrate contemporary natural selection is acting on MHC class II genes in Soay sheep and the mode of selection on specific fitness components can be different mode from selection on total fitness.
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Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Kara L Dicks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,Royal Zoological Society of Scotland, Edinburgh, UK
| | - Jarrod D Hadfield
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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15
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Chevin L, Gompert Z, Nosil P. Frequency dependence and the predictability of evolution in a changing environment. Evol Lett 2021; 6:21-33. [PMID: 35127135 PMCID: PMC8802243 DOI: 10.1002/evl3.266] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/28/2021] [Accepted: 11/22/2021] [Indexed: 11/09/2022] Open
Abstract
Frequency‐dependent (FD) selection, whereby fitness and selection depend on the genetic or phenotypic composition of the population, arises in numerous ecological contexts (competition, mate choice, crypsis, mimicry, etc.) and can strongly impact evolutionary dynamics. In particular, negative frequency‐dependent selection (NFDS) is well known for its ability to potentially maintain stable polymorphisms, but it has also been invoked as a source of persistent, predictable frequency fluctuations. However, the conditions under which such fluctuations persist are not entirely clear. In particular, previous work rarely considered that FD is unlikely to be the sole driver of evolutionary dynamics when it occurs, because most environments are not static but instead change dynamically over time. Here, we investigate how FD interacts with a temporally fluctuating environment to shape the dynamics of population genetic change. We show that a simple metric introduced by Lewontin, the slope of frequency change against frequency near equilibrium, works as a key criterion for distinguishing microevolutionary outcomes, even in a changing environment. When this slope D is between 0 and –2 (consistent with the empirical examples we review), substantial fluctuations would not persist on their own in a large population occupying a constant environment, but they can still be maintained indefinitely as quasi‐cycles fueled by environmental noise or genetic drift. However, such moderate NFDS buffers and temporally shifts evolutionary responses to periodic environments (e.g., seasonality). Stronger FD, with slope D < –2, can produce self‐sustained cycles that may overwhelm responses to a changing environment, or even chaos that fundamentally limits predictability. This diversity of expected outcomes, together with the empirical evidence for both FD and environment‐dependent selection, suggests that the interplay of internal dynamics with external forcing should be investigated more systematically to reach a better understanding and prediction of evolution.
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Affiliation(s)
| | | | - Patrik Nosil
- CEFE, Univ Montpellier, CNRS, EPHE, IRD Montpellier 34090 France
- Department of Biology Utah State University Logan Utah 84322 USA
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16
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Huang W, Dicks KL, Ballingall KT, Johnston SE, Sparks AM, Watt K, Pilkington JG, Pemberton JM. Associations between MHC class II variation and phenotypic traits in a free-living sheep population. Mol Ecol 2021; 31:902-915. [PMID: 34748666 DOI: 10.1111/mec.16265] [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: 04/15/2021] [Revised: 10/22/2021] [Accepted: 11/03/2021] [Indexed: 01/03/2023]
Abstract
Pathogen-mediated selection (PMS) is thought to maintain the high level of allelic diversity observed in the major histocompatibility complex (MHC) class II genes. A comprehensive way to demonstrate contemporary selection is to examine associations between MHC variation and individual fitness. As individual fitness is hard to measure, many studies examine associations between MHC variation and phenotypic traits, including direct or indirect measures of adaptive immunity thought to contribute to fitness. Here, we tested associations between MHC class II variation and five phenotypic traits measured in free-living sheep captured in August: weight, strongyle faecal egg count, and plasma IgA, IgE and IgG immunoglobulin titres against the gastrointestinal nematode parasite Teladorsagia circumcincta. We found no association between MHC class II variation and weight or strongyle faecal egg count. We did, however, find associations between MHC class II variation and immunoglobulin levels which varied with isotype, age and sex. Our results suggest associations between MHC and phenotypic traits are more likely to be found for traits more closely associated with pathogen defence than integrative traits such as bodyweight and highlight the association between MHC variation and antibodies in wild populations.
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Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Kara L Dicks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Alexandra M Sparks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,School of Biology, University of Leeds, Leeds, UK
| | - Kathryn Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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17
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Middlebrook EA, Stark DL, Cornwall DH, Kubinak JL, Potts WK. Deep Sequencing of MHC-Adapted Viral Lines Reveals Complex Recombinational Exchanges With Endogenous Retroviruses Leading to High-Frequency Variants. Front Genet 2021; 12:716623. [PMID: 34512727 PMCID: PMC8430262 DOI: 10.3389/fgene.2021.716623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/05/2021] [Indexed: 12/03/2022] Open
Abstract
Experimental evolution (serial passage) of Friend virus complex (FVC) in mice demonstrates phenotypic adaptation to specific host major histocompatibility complex (MHC) genotypes. These evolved viral lines show increased fitness and virulence in their host-genotype-of-passage, but display fitness and virulence tradeoffs when infecting unfamiliar host MHC genotypes. Here, we deep sequence these viral lines in an attempt to discover the genetic basis of FVC adaptation. The principal prediction for genotype-specific adaptation is that unique mutations would rise to high frequency in viral lines adapted to each host MHC genotype. This prediction was not supported by our sequencing data as most observed high-frequency variants were present in each of our independently evolved viral lines. However, using a multi-variate approach to measure divergence between viral populations, we show that populations of replicate evolved viral lines from the same MHC congenic mouse strain were more similar to one another than to lines derived from different MHC congenic mouse strains, suggesting that MHC genotype does predictably act on viral evolution in our model. Sequence analysis also revealed rampant recombination with endogenous murine leukemia virus sequences (EnMuLVs) that are encoded within the BALB/c mouse genome. The highest frequency variants in all six lines contained a 12 bp insertion from a recombinant EnMuLV source, suggesting such recombinants were either being favored by selection or were contained in a recombinational hotspot. Interestingly, they did not reach fixation, as if they are low fitness. The amount of background mutations linked to FVC/EnMuLV variable sites indicated that FVC/EnMuLV recombinants had not reached mutation selection equilibrium and thus, that EnMuLV sequences are likely continuously introgressing into the replicating viral population. These discoveries raise the question: is the expression of EnMuLV sequences in mouse splenocytes that permit recombination with exogenous FVC a pathogen or host adaptation?
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Affiliation(s)
- Earl A. Middlebrook
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
- Biosecurity and Public Health, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Derek L. Stark
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
| | - Douglas H. Cornwall
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
- Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - Jason L. Kubinak
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, United States
| | - Wayne K. Potts
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
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18
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Phillips KP, Cable J, Mohammed RS, Chmielewski S, Przesmycka KJ, van Oosterhout C, Radwan J. Functional immunogenetic variation, rather than local adaptation, predicts ectoparasite infection intensity in a model fish species. Mol Ecol 2021; 30:5588-5604. [PMID: 34415650 PMCID: PMC9292977 DOI: 10.1111/mec.16135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/07/2021] [Accepted: 08/11/2021] [Indexed: 11/28/2022]
Abstract
Natural host populations differ in their susceptibility to infection by parasites, and these intrapopulation differences are still an incompletely understood component of host‐parasite dynamics. In this study, we used controlled infection experiments with wild‐caught guppies (Poecilia reticulata) and their ectoparasite Gyrodactylus turnbulli to investigate the roles of local adaptation and host genetic composition (immunogenetic and neutral) in explaining differences in susceptibility to infection. We found differences between our four study host populations that were consistent between two parasite source populations, with no indication of local adaptation by either host or parasite at two tested spatial scales. Greater values of host population genetic variability metrics broadly aligned with lower population mean infection intensity, with the best alignments associated with major histocompatibility complex (MHC) “supertypes”. Controlling for intrapopulation differences and potential inbreeding variance, we found a significant negative relationship between individual‐level functional MHC variability and infection: fish carrying more MHC supertypes experienced infections of lower severity, with limited evidence for supertype‐specific effects. We conclude that population‐level differences in host infection susceptibility probably reflect variation in parasite selective pressure and/or host evolutionary potential, underpinned by functional immunogenetic variation.
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Affiliation(s)
- Karl P Phillips
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.,School of Biological Earth & Environmental Sciences, University College Cork, Cork, Ireland.,Marine Institute, Newport, Co. Mayo, Ireland
| | - Joanne Cable
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Ryan S Mohammed
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.,Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Sebastian Chmielewski
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Karolina J Przesmycka
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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19
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Bourgeois Y, Fields P, Bento G, Ebert D. Balancing selection for pathogen resistance reveals an intercontinental signature of Red Queen coevolution. Mol Biol Evol 2021; 38:4918-4933. [PMID: 34289047 PMCID: PMC8557431 DOI: 10.1093/molbev/msab217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The link between long-term host–parasite coevolution and genetic diversity is key to understanding genetic epidemiology and the evolution of resistance. The model of Red Queen host–parasite coevolution posits that high genetic diversity is maintained when rare host resistance variants have a selective advantage, which is believed to be the mechanistic basis for the extraordinarily high levels of diversity at disease-related genes such as the major histocompatibility complex in jawed vertebrates and R-genes in plants. The parasites that drive long-term coevolution are, however, often elusive. Here we present evidence for long-term balancing selection at the phenotypic (variation in resistance) and genomic (resistance locus) level in a particular host–parasite system: the planktonic crustacean Daphnia magna and the bacterium Pasteuria ramosa. The host shows widespread polymorphisms for pathogen resistance regardless of geographic distance, even though there is a clear genome-wide pattern of isolation by distance at other sites. In the genomic region of a previously identified resistance supergene, we observed consistent molecular signals of balancing selection, including higher genetic diversity, older coalescence times, and lower differentiation between populations, which set this region apart from the rest of the genome. We propose that specific long-term coevolution by negative-frequency-dependent selection drives this elevated diversity at the host's resistance loci on an intercontinental scale and provide an example of a direct link between the host’s resistance to a virulent pathogen and the large-scale diversity of its underlying genes.
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Affiliation(s)
- Yann Bourgeois
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Peter Fields
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Gilberto Bento
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Dieter Ebert
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
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20
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Baert JM, Stienen EWM, Verbruggen F, Van de Weghe N, Lens L, Müller W. Context‐dependent specialisation drives temporal dynamics in intra‐ and inter‐individual variation in foraging behaviour within a generalist bird population. OIKOS 2021. [DOI: 10.1111/oik.08067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jan M. Baert
- Dept of Biology, Behavioural Ecology and Ecophysiology Group, Univ. of Antwerp Antwerp Belgium
- Dept of Biology, Terrestrial Ecology Unit, Ghent Univ. Ghent Belgium
| | | | | | | | - Luc Lens
- Dept of Biology, Terrestrial Ecology Unit, Ghent Univ. Ghent Belgium
| | - Wendt Müller
- Dept of Biology, Behavioural Ecology and Ecophysiology Group, Univ. of Antwerp Antwerp Belgium
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21
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Exploring ecological specialization in pipefish using genomic, morphometric and ecological evidence. DIVERS DISTRIB 2021. [DOI: 10.1111/ddi.13286] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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22
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Martin CH, Gould KJ. Surprising spatiotemporal stability of a multi-peak fitness landscape revealed by independent field experiments measuring hybrid fitness. Evol Lett 2020; 4:530-544. [PMID: 33312688 PMCID: PMC7719547 DOI: 10.1002/evl3.195] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 12/14/2022] Open
Abstract
The effect of the environment on fitness in natural populations is a fundamental question in evolutionary biology. However, experimental manipulations of both environment and phenotype at the same time are rare. Thus, the relative importance of the competitive environment versus intrinsic organismal performance in shaping the location, height, and fluidity of fitness peaks and valleys remains largely unknown. Here, we experimentally tested the effect of competitor frequency on the complex fitness landscape driving adaptive radiation of a generalist and two trophic specialist pupfishes, a scale-eater and molluscivore, endemic to hypersaline lakes on San Salvador Island (SSI), Bahamas. We manipulated phenotypes, by generating 3407 F4/F5 lab-reared hybrids, and competitive environment, by altering the frequency of rare transgressive hybrids between field enclosures in two independent lake populations. We then tracked hybrid survival and growth rates across these four field enclosures for 3-11 months. In contrast to competitive speciation theory, we found no evidence that the frequency of hybrid phenotypes affected their survival. Instead, we observed a strikingly similar fitness landscape to a previous independent field experiment, each supporting multiple fitness peaks for generalist and molluscivore phenotypes and a large fitness valley isolating the divergent scale-eater phenotype. These features of the fitness landscape were stable across manipulated competitive environments, multivariate trait axes, and spatiotemporal heterogeneity. We suggest that absolute performance constraints and divergent gene regulatory networks shape macroevolutionary (interspecific) fitness landscapes in addition to microevolutionary (intraspecific) competitive dynamics. This interplay between organism and environment underlies static and dynamic features of the adaptive landscape.
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Affiliation(s)
- Christopher H. Martin
- Department of Integrative BiologyUniversity of California, BerkeleyBerkeleyCalifornia94720
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia94720
| | - Katelyn J. Gould
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNorth Carolina27515
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23
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Increasing our ability to predict contemporary evolution. Nat Commun 2020; 11:5592. [PMID: 33154385 PMCID: PMC7645684 DOI: 10.1038/s41467-020-19437-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/15/2020] [Indexed: 12/21/2022] Open
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24
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Hülsmann L, Chisholm RA, Hartig F. Is Variation in Conspecific Negative Density Dependence Driving Tree Diversity Patterns at Large Scales? Trends Ecol Evol 2020; 36:151-163. [PMID: 33589047 DOI: 10.1016/j.tree.2020.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023]
Abstract
Half a century ago, Janzen and Connell hypothesized that the high tree species diversity in tropical forests is maintained by specialized natural enemies. Along with other mechanisms, these can cause conspecific negative density dependence (CNDD) and thus maintain species diversity. Numerous studies have measured proxies of CNDD worldwide, but doubt about its relative importance remains. We find ample evidence for CNDD in local populations, but methodological limitations make it difficult to assess if CNDD scales up to control community diversity and thereby local and global biodiversity patterns. A combination of more robust statistical methods, new study designs, and eco-evolutionary models are needed to provide a more definite evaluation of the importance of CNDD for geographic variation in plant species diversity.
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Affiliation(s)
- Lisa Hülsmann
- Theoretical Ecology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Ryan A Chisholm
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Florian Hartig
- Theoretical Ecology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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25
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Liu C, Lei H, Ran X, Wang J. Genetic variation and selection in the major histocompatibility complex Class II gene in the Guizhou pony. PeerJ 2020; 8:e9889. [PMID: 32999762 PMCID: PMC7505079 DOI: 10.7717/peerj.9889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/17/2020] [Indexed: 11/20/2022] Open
Abstract
The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including DQA, DRA, DQB, and DRB, and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. DRA had the lowest dN/dS ratio (0.560) compared with the other three loci, indicating that DRA was conserved and could be conserved after undergoing selective processes. Nine DQA, five DQB, nine DRA, and seven DRB codons were under significant positive selection at the antigen binding sites (ABS), suggesting that the selected residues in ABS may play a significant role in the innate immune system of the GZP. Two GZP alleles were shared with Przewalski’s horse, and six older GZP haplotypes had a better relationship with other horse species by one or two mutational steps, indicating that the GZP may be a natural ancient variety of equid. The specific diversity of ABS and the numbers of unique haplotypes in the evolutionary process affords this species a better genetic fitness and ability to adapt to the native environment.
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Affiliation(s)
- Chang Liu
- College of Animal Sciences, Guizhou University, Guiyang, China.,College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Hongmei Lei
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Xueqin Ran
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Jiafu Wang
- College of Animal Sciences, Guizhou University, Guiyang, China.,Tongren University, Tongren, China
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26
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Ebert D, Fields PD. Host-parasite co-evolution and its genomic signature. Nat Rev Genet 2020; 21:754-768. [PMID: 32860017 DOI: 10.1038/s41576-020-0269-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2020] [Indexed: 01/14/2023]
Abstract
Studies in diverse biological systems have indicated that host-parasite co-evolution is responsible for the extraordinary genetic diversity seen in some genomic regions, such as major histocompatibility (MHC) genes in jawed vertebrates and resistance genes in plants. This diversity is believed to evolve under balancing selection on hosts by parasites. However, the mechanisms that link the genomic signatures in these regions to the underlying co-evolutionary process are only slowly emerging. We still lack a clear picture of the co-evolutionary concepts and of the genetic basis of the co-evolving phenotypic traits in the interacting antagonists. Emerging genomic tools that provide new options for identifying underlying genes will contribute to a fuller understanding of the co-evolutionary process.
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Affiliation(s)
- Dieter Ebert
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland. .,Wissenschaftskolleg zu Berlin, Berlin, Germany.
| | - Peter D Fields
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland
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Radwan J, Babik W, Kaufman J, Lenz TL, Winternitz J. Advances in the Evolutionary Understanding of MHC Polymorphism. Trends Genet 2020; 36:298-311. [DOI: 10.1016/j.tig.2020.01.008] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 12/26/2022]
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Terekhanova NV, Barmintseva AE, Kondrashov AS, Bazykin GA, Mugue NS. Architecture of Parallel Adaptation in Ten Lacustrine Threespine Stickleback Populations from the White Sea Area. Genome Biol Evol 2020; 11:2605-2618. [PMID: 31406984 PMCID: PMC6761963 DOI: 10.1093/gbe/evz175] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2019] [Indexed: 12/20/2022] Open
Abstract
Adaptation of threespine stickleback to freshwater involves parallel recruitment of freshwater alleles in clusters of closely linked sites, or divergence islands (DIs). However, it remains unclear to what extent the DIs and the alleles that constitute them coincide between populations that underwent adaptation to freshwater independently. We examine threespine sticklebacks from ten freshwater lakes that emerged 500–1500 years ago in the White Sea basin, with the emphasis on repeatability of genomic patterns of adaptation among the lake populations and the role of local recombination rate in the distribution and structure of DIs. The 65 detected DIs are clustered in the genome, forming 12 aggregations, and this clustering cannot be explained by the variation of the recombination rate. Only 21 of the DIs are present in all the freshwater populations, likely being indispensable for successful colonization of freshwater environment by the ancestral marine population. Within most DIs, the same set of single nucleotide polymorphisms (SNPs) distinguish marine and freshwater haplotypes in all the lake populations; however, in some DIs, freshwater alleles differ between populations, suggesting that they could have been established by recruitment of different haplotypes in different populations.
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Affiliation(s)
- Nadezhda V Terekhanova
- Skolkovo Institute of Science and Technology, Skolkovo, Russia.,Sector for Molecular Evolution, Institute for Information Transmission Problems of the RAS (Kharkevich Institute), Moscow, Russia
| | - Anna E Barmintseva
- Laboratory of Molecular Genetics, Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia
| | - Alexey S Kondrashov
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan.,M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Georgii A Bazykin
- Skolkovo Institute of Science and Technology, Skolkovo, Russia.,Sector for Molecular Evolution, Institute for Information Transmission Problems of the RAS (Kharkevich Institute), Moscow, Russia
| | - Nikolai S Mugue
- Laboratory of Molecular Genetics, Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia.,N. K. Koltzov Institute of Developmental Biology RAS, Moscow, Russia
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29
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Gaigher A, Burri R, San-Jose LM, Roulin A, Fumagalli L. Lack of statistical power as a major limitation in understanding MHC-mediated immunocompetence in wild vertebrate populations. Mol Ecol 2019; 28:5115-5132. [PMID: 31614047 DOI: 10.1111/mec.15276] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 10/07/2019] [Accepted: 10/11/2019] [Indexed: 01/09/2023]
Abstract
Disentangling the sources of variation in developing an effective immune response against pathogens is of major interest to immunoecology and evolutionary biology. To date, the link between immunocompetence and genetic variation at the major histocompatibility complex (MHC) has received little attention in wild animals, despite the key role of MHC genes in activating the adaptive immune system. Although several studies point to a link between MHC and immunocompetence, negative findings have also been reported. Such disparate findings suggest that limited statistical power might be affecting studies on this topic, owing to insufficient sample sizes and/or a generally small effect of MHC on the immunocompetence of wild vertebrates. To clarify this issue, we investigated the link between MHC variation and seven immunocompetence proxies in a large sample of barn owls and estimated the effect sizes and statistical power of this and published studies on this topic. We found that MHC poorly explained variation in immunocompetence of barn owls, with small-to-moderate associations between MHC and immunocompetence in owls (effect size: .1 ≥ r ≤ .3) similar to other vertebrates studied to date. Such small-to-moderate effects were largely associated with insufficient power, which was only sufficient (>0.8) to detect moderate-to-large effect sizes (r ≥ .3). Thus, studies linking MHC variation with immunocompetence in wild populations are underpowered to detect MHC effects, which are likely to be of generally small magnitude. Larger sample sizes (>200) will be required to achieve sufficient power in future studies aiming to robustly test for a link between MHC variation and immunocompetence.
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Affiliation(s)
- Arnaud Gaigher
- Department of Ecology and Evolution, Laboratory for Conservation Biology, Biophore, University of Lausanne, Lausanne, Switzerland.,Department of Computational Biology, Génopode, University of Lausanne, Lausanne, Switzerland.,CIBIO-InBIO, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal
| | - Reto Burri
- Department of Population Ecology, Institute of Ecology & Evolution, Friedrich Schiller University Jena, Jena, Germany
| | - Luis M San-Jose
- Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland.,Laboratoire Évolution & Diversité Biologique, UMR 5174, CNRS, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Alexandre Roulin
- Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland
| | - Luca Fumagalli
- Department of Ecology and Evolution, Laboratory for Conservation Biology, Biophore, University of Lausanne, Lausanne, Switzerland
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30
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Lindsay WR, Andersson S, Bererhi B, Höglund J, Johnsen A, Kvarnemo C, Leder EH, Lifjeld JT, Ninnes CE, Olsson M, Parker GA, Pizzari T, Qvarnström A, Safran RJ, Svensson O, Edwards SV. Endless forms of sexual selection. PeerJ 2019; 7:e7988. [PMID: 31720113 PMCID: PMC6839514 DOI: 10.7717/peerj.7988] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022] Open
Abstract
In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a “stock-taking” workshop on sexual selection and sexual conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.
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Affiliation(s)
- Willow R Lindsay
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Staffan Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Badreddine Bererhi
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Jacob Höglund
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Arild Johnsen
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Erica H Leder
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Jan T Lifjeld
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Calum E Ninnes
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden.,Department of Entomology and Nematology, University of Florida, Gainesville, FL, United States of America
| | - Mats Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Geoff A Parker
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Tommaso Pizzari
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, United Kingdom
| | - Anna Qvarnström
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Rebecca J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, United States of America
| | - Ola Svensson
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America.,Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology, Göteborg, Sweden
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31
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Näpflin K, O'Connor EA, Becks L, Bensch S, Ellis VA, Hafer-Hahmann N, Harding KC, Lindén SK, Olsen MT, Roved J, Sackton TB, Shultz AJ, Venkatakrishnan V, Videvall E, Westerdahl H, Winternitz JC, Edwards SV. Genomics of host-pathogen interactions: challenges and opportunities across ecological and spatiotemporal scales. PeerJ 2019; 7:e8013. [PMID: 31720122 PMCID: PMC6839515 DOI: 10.7717/peerj.8013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022] Open
Abstract
Evolutionary genomics has recently entered a new era in the study of host-pathogen interactions. A variety of novel genomic techniques has transformed the identification, detection and classification of both hosts and pathogens, allowing a greater resolution that helps decipher their underlying dynamics and provides novel insights into their environmental context. Nevertheless, many challenges to a general understanding of host-pathogen interactions remain, in particular in the synthesis and integration of concepts and findings across a variety of systems and different spatiotemporal and ecological scales. In this perspective we aim to highlight some of the commonalities and complexities across diverse studies of host-pathogen interactions, with a focus on ecological, spatiotemporal variation, and the choice of genomic methods used. We performed a quantitative review of recent literature to investigate links, patterns and potential tradeoffs between the complexity of genomic, ecological and spatiotemporal scales undertaken in individual host-pathogen studies. We found that the majority of studies used whole genome resolution to address their research objectives across a broad range of ecological scales, especially when focusing on the pathogen side of the interaction. Nevertheless, genomic studies conducted in a complex spatiotemporal context are currently rare in the literature. Because processes of host-pathogen interactions can be understood at multiple scales, from molecular-, cellular-, and physiological-scales to the levels of populations and ecosystems, we conclude that a major obstacle for synthesis across diverse host-pathogen systems is that data are collected on widely diverging scales with different degrees of resolution. This disparity not only hampers effective infrastructural organization of the data but also data granularity and accessibility. Comprehensive metadata deposited in association with genomic data in easily accessible databases will allow greater inference across systems in the future, especially when combined with open data standards and practices. The standardization and comparability of such data will facilitate early detection of emerging infectious diseases as well as studies of the impact of anthropogenic stressors, such as climate change, on disease dynamics in humans and wildlife.
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Affiliation(s)
- Kathrin Näpflin
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America
| | - Emily A O'Connor
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Lutz Becks
- Aquatic Ecology and Evolution, Limnological Institute University Konstanz, Konstanz, Germany
| | - Staffan Bensch
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Vincenzo A Ellis
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Nina Hafer-Hahmann
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany.,EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Karin C Harding
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.,Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden
| | - Sara K Lindén
- Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Morten T Olsen
- Section for Evolutionary Genomics, Natural History Museum of Denmark, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Roved
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Timothy B Sackton
- Informatics Group, Harvard University, Cambridge, MA, United States of America
| | - Allison J Shultz
- Ornithology Department, Natural History Museum of Los Angeles County, Los Angeles, CA, United States of America
| | - Vignesh Venkatakrishnan
- Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elin Videvall
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden.,Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Jamie C Winternitz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America.,Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden
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32
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MARTIN CHRISTOPHERH, RICHARDS EMILIEJ. The paradox behind the pattern of rapid adaptive radiation: how can the speciation process sustain itself through an early burst? ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2019; 50:569-593. [PMID: 36237480 PMCID: PMC9555815 DOI: 10.1146/annurev-ecolsys-110617-062443] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
Rapid adaptive radiation poses a distinct question apart from speciation and adaptation: what happens after one speciation event? That is, how are some lineages able to continue speciating through a rapid burst? This question connects global macroevolutionary patterns to microevolutionary processes. Here we review major features of rapid radiations in nature and their mismatch with theoretical models and what is currently known about speciation mechanisms. Rapid radiations occur on three major diversification axes - species richness, phenotypic disparity, and ecological diversity - with exceptional outliers on each axis. The paradox is that the hallmark early stage of adaptive radiation, a rapid burst of speciation and niche diversification, is contradicted by most existing speciation models which instead predict continuously decelerating speciation rates and niche subdivision through time. Furthermore, while speciation mechanisms such as magic traits, phenotype matching, and physical linkage of co-adapted alleles promote speciation, it is often not discussed how these mechanisms could promote multiple speciation events in rapid succession. Additional mechanisms beyond ecological opportunity are needed to understand how rapid radiations occur. We review the evidence for five emerging theories: 1) the 'transporter' hypothesis: introgression and the ancient origins of adaptive alleles, 2) the 'signal complexity' hypothesis: the dimensionality of sexual traits, 3) the connectivity of fitness landscapes, 4) 'diversity begets diversity', and 5) flexible stem/'plasticity first'. We propose new questions and predictions to guide future work on the mechanisms underlying the rare origins of rapid radiation.
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Affiliation(s)
- CHRISTOPHER H. MARTIN
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
- Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
| | - EMILIE J. RICHARDS
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
- Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
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33
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Svensson EI, Connallon T. How frequency-dependent selection affects population fitness, maladaptation and evolutionary rescue. Evol Appl 2019; 12:1243-1258. [PMID: 31417612 PMCID: PMC6691226 DOI: 10.1111/eva.12714] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/31/2018] [Accepted: 09/12/2018] [Indexed: 01/04/2023] Open
Abstract
Frequency-dependent (FD) selection is a central process maintaining genetic variation and mediating evolution of population fitness. FD selection has attracted interest from researchers in a wide range of biological subdisciplines, including evolutionary genetics, behavioural ecology and, more recently, community ecology. However, the implications of frequency dependence for applied biological problems, particularly maladaptation, biological conservation and evolutionary rescue remain underexplored. The neglect of FD selection in conservation is particularly unfortunate. Classical theory, dating back to the 1940s, demonstrated that frequency dependence can either increase or decrease population fitness. These evolutionary consequences of FD selection are relevant to modern concerns about population persistence and the capacity of evolution to alleviate extinction risks. But exactly when should we expect FD selection to increase versus decrease absolute fitness and population growth? And how much of an impact is FD selection expected to have on population persistence versus extinction in changing environments? The answers to these questions have implications for evolutionary rescue under climate change and may inform strategies for managing threatened populations. Here, we revisit the core theory of FD selection, reviewing classical single-locus models of population genetic change and outlining short- and long-run consequences of FD selection for the evolution of population fitness. We then develop a quantitative genetic model of evolutionary rescue in a deteriorating environment, with population persistence hinging upon the evolution of a quantitative trait subject to both frequency-dependent and frequency-independent natural selection. We discuss the empirical literature pertinent to this theory, which supports key assumptions of our model. We show that FD selection can promote population persistence when it aligns with the direction of frequency-independent selection imposed by abiotic environmental conditions. However, under most scenarios of environmental change, FD selection limits a population's evolutionary responsiveness to changing conditions and narrows the rate of environmental change that is evolutionarily tolerable.
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Affiliation(s)
- Erik I. Svensson
- Evolutionary Ecology UnitDepartment of BiologyLund UniversityLundSweden
| | - Tim Connallon
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
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34
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Berbel‐Filho WM, Garcia de Leaniz C, Morán P, Cable J, Lima SMQ, Consuegra S. Local parasite pressures and host genotype modulate epigenetic diversity in a mixed-mating fish. Ecol Evol 2019; 9:8736-8748. [PMID: 31410276 PMCID: PMC6686343 DOI: 10.1002/ece3.5426] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/07/2019] [Accepted: 06/14/2019] [Indexed: 12/15/2022] Open
Abstract
Parasite-mediated selection is one of the main drivers of genetic variation in natural populations. The persistence of long-term self-fertilization, however, challenges the notion that low genetic variation and inbreeding compromise the host's ability to respond to pathogens. DNA methylation represents a potential mechanism for generating additional adaptive variation under low genetic diversity. We compared genetic diversity (microsatellites and AFLPs), variation in DNA methylation (MS-AFLPs), and parasite loads in three populations of Kryptolebias hermaphroditus, a predomintanly self-fertilizing fish, to analyze the potential adaptive value of DNA methylation in relation to genetic diversity and parasite loads. We found strong genetic population structuring, as well as differences in parasite loads and methylation levels among sampling sites and selfing lineages. Globally, the interaction between parasites and inbreeding with selfing lineages influenced DNA methylation, but parasites seemed more important in determining methylation levels at the local scale.
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Affiliation(s)
| | | | - Paloma Morán
- Facultad de BiologíaUniversity of Vigo. Campus Universitario Lagoas‐MarcosendeVigoSpain
| | - Joanne Cable
- School of BiosciencesCardiff UniversityCardiffUK
| | - Sergio M. Q. Lima
- Laboratório de Ictiologia Sistemática e Evolutiva, Departamento de Botânica e ZoologiaUniversidade Federal do Rio Grande do NorteNatalBrazil
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35
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Lane JE, Czenze ZJ, Findlay-Robinson R, Bayne E. Phenotypic Plasticity and Local Adaptation in a Wild Hibernator Evaluated through Reciprocal Translocation. Am Nat 2019; 194:516-528. [PMID: 31490723 DOI: 10.1086/702313] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Phenological shifts are the most commonly reported ecological responses to climate change and can be produced rapidly by phenotypic plasticity. However, both the limits of plasticity and whether it will be sufficient to maintain local adaptation (or even lead to maladaptation) are less clear. Increased winter precipitation has been shown to lead to phenological delays and corresponding annual decreases in fitness in Columbian ground squirrels (Urocitellus columbianus). We took advantage of natural phenological variation (across elevations) in this species to better assess the extent of phenotypic plasticity in emergence dates and the relationships between emergence dates and individual annual fitness. We coupled a reciprocal translocation experiment with natural monitoring across two populations separated by ∼500 m in elevation. Individuals in both populations responded plastically to both spring temperature and winter precipitation. Translocated individuals adjusted their emergence dates to approach those of individuals in their adoptive populations but did differ significantly in their emergence dates from residents. There were no differences in annual fitness among treatment groups nor selection on emergence date within a year. Phenotypic plasticity is thus sufficient to allow individuals to respond to broad environmental gradients, but the influence of variation in emergence dates on annual fitness requires further investigation.
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36
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Lowe WH, Addis BR. Matching habitat choice and plasticity contribute to phenotype–environment covariation in a stream salamander. Ecology 2019; 100:e02661. [DOI: 10.1002/ecy.2661] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/07/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Winsor H. Lowe
- Division of Biological Sciences University of Montana Missoula Montana 59812 USA
| | - Brett R. Addis
- Division of Biological Sciences University of Montana Missoula Montana 59812 USA
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37
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van den Bosch M, Baert JM, Müller W, Lens L, Stienen EWM. Specialization reduces foraging effort and improves breeding performance in a generalist bird. Behav Ecol 2019. [DOI: 10.1093/beheco/arz016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Jan M Baert
- Terrestrial Ecology Unit (TEREC), Ghent University, Ghent, Belgium
- Behavioural Ecology and Ecophysiology Research Group, University of Antwerp, Antwerp, Belgium
| | - Wendt Müller
- Behavioural Ecology and Ecophysiology Research Group, University of Antwerp, Antwerp, Belgium
| | - Luc Lens
- Terrestrial Ecology Unit (TEREC), Ghent University, Ghent, Belgium
| | - Eric W M Stienen
- Research Institute for Nature and Forest (INBO), Brussels, Belgium
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38
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Shaw RG. From the Past to the Future: Considering the Value and Limits of Evolutionary Prediction. Am Nat 2019; 193:1-10. [DOI: 10.1086/700565] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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39
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Rajkov J, Weber AA, Salzburger W, Egger B. Adaptive phenotypic plasticity contributes to divergence between lake and river populations of an East African cichlid fish. Ecol Evol 2018; 8:7323-7333. [PMID: 30151152 PMCID: PMC6106192 DOI: 10.1002/ece3.4241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/03/2018] [Accepted: 05/04/2018] [Indexed: 01/01/2023] Open
Abstract
Adaptive phenotypic plasticity and fixed genotypic differences have long been considered opposing strategies in adaptation. More recently, these mechanisms have been proposed to act complementarily and under certain conditions jointly facilitate evolution, speciation, and even adaptive radiations. Here, we investigate the relative contributions of adaptive phenotypic plasticity vs. local adaptation to fitness, using an emerging model system to study early phases of adaptive divergence, the generalist cichlid fish species Astatotilapia burtoni. We tested direct fitness consequences of morphological divergence between lake and river populations in nature by performing two transplant experiments in Lake Tanganyika. In the first experiment, we used wild-caught juvenile lake and river individuals, while in the second experiment, we used F1 crosses between lake and river fish bred in a common garden setup. By tracking the survival and growth of translocated individuals in enclosures in the lake over several weeks, we revealed local adaptation evidenced by faster growth of the wild-caught resident population in the first experiment. On the other hand, we did not find difference in growth between different types of F1 crosses in the second experiment, suggesting a substantial contribution of adaptive phenotypic plasticity to increased immigrant fitness. Our findings highlight the value of formally comparing fitness of wild-caught and common garden-reared individuals and emphasize the necessity of considering adaptive phenotypic plasticity in the study of adaptive divergence.
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Affiliation(s)
- Jelena Rajkov
- Zoological InstituteUniversity of BaselBaselSwitzerland
| | | | | | - Bernd Egger
- Zoological InstituteUniversity of BaselBaselSwitzerland
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40
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Liu S, Ferchaud AL, Grønkjaer P, Nygaard R, Hansen MM. Genomic parallelism and lack thereof in contrasting systems of three-spined sticklebacks. Mol Ecol 2018; 27:4725-4743. [DOI: 10.1111/mec.14782] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/01/2018] [Accepted: 05/14/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Shenglin Liu
- Department of Bioscience; Aarhus University; Aarhus C Denmark
| | - Anne-Laure Ferchaud
- Département de Biologie; Institut de Biologie Intégrative et des Systèmes (IBIS); Université Laval; Québec QC Canada
| | - Peter Grønkjaer
- Department of Bioscience; Aarhus University; Aarhus C Denmark
| | - Rasmus Nygaard
- Greenland Institute of Natural Resources; Nuuk Greenland
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Ravinet M, Yoshida K, Shigenobu S, Toyoda A, Fujiyama A, Kitano J. The genomic landscape at a late stage of stickleback speciation: High genomic divergence interspersed by small localized regions of introgression. PLoS Genet 2018; 14:e1007358. [PMID: 29791436 PMCID: PMC5988309 DOI: 10.1371/journal.pgen.1007358] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 06/05/2018] [Accepted: 04/11/2018] [Indexed: 12/17/2022] Open
Abstract
Speciation is a continuous process and analysis of species pairs at different stages of divergence provides insight into how it unfolds. Previous genomic studies on young species pairs have revealed peaks of divergence and heterogeneous genomic differentiation. Yet less known is how localised peaks of differentiation progress to genome-wide divergence during the later stages of speciation in the presence of persistent gene flow. Spanning the speciation continuum, stickleback species pairs are ideal for investigating how genomic divergence builds up during speciation. However, attention has largely focused on young postglacial species pairs, with little knowledge of the genomic signatures of divergence and introgression in older stickleback systems. The Japanese stickleback species pair, composed of the Pacific Ocean three-spined stickleback (Gasterosteus aculeatus) and the Japan Sea stickleback (G. nipponicus), which co-occur in the Japanese islands, is at a late stage of speciation. Divergence likely started well before the end of the last glacial period and crosses between Japan Sea females and Pacific Ocean males result in hybrid male sterility. Here we use coalescent analyses and Approximate Bayesian Computation to show that the two species split approximately 0.68-1 million years ago but that they have continued to exchange genes at a low rate throughout divergence. Population genomic data revealed that, despite gene flow, a high level of genomic differentiation is maintained across the majority of the genome. However, we identified multiple, small regions of introgression, occurring mainly in areas of low recombination rate. Our results demonstrate that a high level of genome-wide divergence can establish in the face of persistent introgression and that gene flow can be localized to small genomic regions at the later stages of speciation with gene flow.
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Affiliation(s)
- Mark Ravinet
- Division of Ecological Genetics, Department of Population Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Kohta Yoshida
- Division of Ecological Genetics, Department of Population Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Asao Fujiyama
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Jun Kitano
- Division of Ecological Genetics, Department of Population Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
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Nosil P, Villoutreix R, de Carvalho CF, Farkas TE, Soria-Carrasco V, Feder JL, Crespi BJ, Gompert Z. Natural selection and the predictability of evolution in Timema stick insects. Science 2018; 359:765-770. [PMID: 29449486 DOI: 10.1126/science.aap9125] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 12/21/2017] [Indexed: 01/03/2023]
Abstract
Predicting evolution remains difficult. We studied the evolution of cryptic body coloration and pattern in a stick insect using 25 years of field data, experiments, and genomics. We found that evolution is more difficult to predict when it involves a balance between multiple selective factors and uncertainty in environmental conditions than when it involves feedback loops that cause consistent back-and-forth fluctuations. Specifically, changes in color-morph frequencies are modestly predictable through time (r2 = 0.14) and driven by complex selective regimes and yearly fluctuations in climate. In contrast, temporal changes in pattern-morph frequencies are highly predictable due to negative frequency-dependent selection (r2 = 0.86). For both traits, however, natural selection drives evolution around a dynamic equilibrium, providing some predictability to the process.
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Affiliation(s)
- Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - Romain Villoutreix
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | | | - Timothy E Farkas
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06369, USA
| | - Víctor Soria-Carrasco
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Bernard J Crespi
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Zach Gompert
- Department of Biology, Utah State University, Logan, UT 84322, USA.
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Phillips KP, Cable J, Mohammed RS, Herdegen-Radwan M, Raubic J, Przesmycka KJ, van Oosterhout C, Radwan J. Immunogenetic novelty confers a selective advantage in host-pathogen coevolution. Proc Natl Acad Sci U S A 2018; 115:1552-1557. [PMID: 29339521 PMCID: PMC5816137 DOI: 10.1073/pnas.1708597115] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The major histocompatibility complex (MHC) is crucial to the adaptive immune response of vertebrates and is among the most polymorphic gene families known. Its high diversity is usually attributed to selection imposed by fast-evolving pathogens. Pathogens are thought to evolve to escape recognition by common immune alleles, and, hence, novel MHC alleles, introduced through mutation, recombination, or gene flow, are predicted to give hosts superior resistance. Although this theoretical prediction underpins host-pathogen "Red Queen" coevolution, it has not been demonstrated in the context of natural MHC diversity. Here, we experimentally tested whether novel MHC variants (both alleles and functional "supertypes") increased resistance of guppies (Poecilia reticulata) to a common ectoparasite (Gyrodactylus turnbulli). We used exposure-controlled infection trials with wild-sourced parasites, and Gyrodactylus-naïve host fish that were F2 descendants of crossed wild populations. Hosts carrying MHC variants (alleles or supertypes) that were new to a given parasite population experienced a 35-37% reduction in infection intensity, but the number of MHC variants carried by an individual, analogous to heterozygosity in single-locus systems, was not a significant predictor. Our results provide direct evidence of novel MHC variant advantage, confirming a fundamental mechanism underpinning the exceptional polymorphism of this gene family and highlighting the role of immunogenetic novelty in host-pathogen coevolution.
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Affiliation(s)
- Karl P Phillips
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, 60-614 Poznań, Poland
- School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
| | - Joanne Cable
- School of Biosciences, Cardiff University, CF10 3AX Cardiff, United Kingdom
| | - Ryan S Mohammed
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Magdalena Herdegen-Radwan
- Department of Behavioural Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Jarosław Raubic
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, 60-614 Poznań, Poland
| | - Karolina J Przesmycka
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, 60-614 Poznań, Poland
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, NR4 7TJ Norwich, United Kingdom
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, 60-614 Poznań, Poland;
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45
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Hamilton's inclusive fitness maintains heritable altruism polymorphism through rb = c. Proc Natl Acad Sci U S A 2018; 115:1860-1864. [PMID: 29295937 DOI: 10.1073/pnas.1710215115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
How can altruism evolve or be maintained in a selfish world? Hamilton's rule shows that the former process will occur when rb > c-the benefits to the recipients of an altruistic act b, weighted by the relatedness between the social partners r, exceed the costs to the altruists c-drives altruistic genotypes spreading against nonaltruistic ones. From this rule, we infer that altruistic genotypes will persist in a population by forming a stable heritable polymorphism with nonaltruistic genotypes if rb = c makes inclusive fitness of the two morphs equal. We test this prediction using the data of 12 years of study on a cooperatively breeding bird, the Tibetan ground tit Pseudopodoces humilis, where helping is performed by males only and kin-directed. Individual variation in ever acting as a helper was heritable (h2 = 0.47), and the resultant altruism polymorphism remained stable as indicated by low-level annual fluctuation of the percentage of helpers among all adult males (24-28%). Helpers' indirect fitness gains from increased lifetime reproductive success of related breeders statistically fully compensated for their lifetime direct fitness losses, suggesting that rb = c holds. While our work provides a fundamental support for Hamilton's idea, it highlights the equivalent inclusive fitness returns to altruists and nonaltruists mediated by rb = c as a theoretically and realistically important mechanism to maintain social polymorphism.
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Lohman BK, Stutz WE, Bolnick DI. Gene expression stasis and plasticity following migration into a foreign environment. Mol Ecol 2017; 26:4657-4670. [DOI: 10.1111/mec.14234] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/09/2017] [Accepted: 06/21/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Brian K. Lohman
- Department of Integrative Biology; University of Texas at Austin; Austin TX USA
| | - William E. Stutz
- Office of Institutional Research; Western Michigan University; Kalamazoo MI USA
| | - Daniel I. Bolnick
- Department of Integrative Biology; University of Texas at Austin; Austin TX USA
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47
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Differences can hold populations together. Nature 2017; 546:218-219. [DOI: 10.1038/nature22502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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48
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Stutz WE, Bolnick DI. Natural selection on MHC IIβ in parapatric lake and stream stickleback: Balancing, divergent, both or neither? Mol Ecol 2017; 26:4772-4786. [PMID: 28437583 DOI: 10.1111/mec.14158] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/12/2022]
Abstract
Major histocompatibility complex (MHC) genes encode proteins that play a central role in vertebrates' adaptive immunity to parasites. MHC loci are among the most polymorphic in vertebrates' genomes, inspiring many studies to identify evolutionary processes driving MHC polymorphism within populations and divergence between populations. Leading hypotheses include balancing selection favouring rare alleles within populations, and spatially divergent selection. These hypotheses do not always produce diagnosably distinct predictions, causing many studies of MHC to yield inconsistent or ambiguous results. We suggest a novel strategy to distinguish balancing vs. divergent selection on MHC, taking advantage of natural admixture between parapatric populations. With divergent selection, individuals with immigrant alleles will be more infected and less fit because they are susceptible to novel parasites in their new habitat. With balancing selection, individuals with locally rare immigrant alleles will be more fit (less infected). We tested these contrasting predictions using three-spine stickleback from three replicate pairs of parapatric lake and stream habitats. We found numerous positive and negative associations between particular MHC IIβ alleles and particular parasite taxa. A few allele-parasite comparisons supported balancing selection, and others supported divergent selection between habitats. But, there was no overall tendency for fish with immigrant MHC alleles to be more or less heavily infected. Instead, locally rare MHC alleles (not necessarily immigrants) were associated with heavier infections. Our results illustrate the complex relationship between MHC IIβ allelic variation and spatially varying multispecies parasite communities: different hypotheses may be concurrently true for different allele-parasite combinations.
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Affiliation(s)
- William E Stutz
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.,Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Daniel I Bolnick
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
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