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Numminen E, Vaumourin E, Parratt SR, Poulin L, Laine AL. Variation and correlations between sexual, asexual and natural enemy resistance life-history traits in a natural plant pathogen population. BMC Evol Biol 2019; 19:142. [PMID: 31299905 PMCID: PMC6624897 DOI: 10.1186/s12862-019-1468-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/26/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Understanding the mechanisms by which diversity is maintained in pathogen populations is critical for epidemiological predictions. Life-history trade-offs have been proposed as a hypothesis for explaining long-term maintenance of variation in pathogen populations, yet the empirical evidence supporting trade-offs has remained mixed. This is in part due to the challenges of documenting successive pathogen life-history stages in many pathosystems. Moreover, little is understood of the role of natural enemies of pathogens on their life-history evolution. RESULTS We characterize life-history-trait variation and possible trade-offs in fungal pathogen Podosphaera plantaginis infecting the host plant Plantago lanceolata. We measured the timing of both asexual and sexual stages, as well as resistance to a hyperparasite of seven pathogen strains that vary in their prevalence in nature. We find significant variation among the strains in their life-history traits that constitute the infection cycle, but no evidence for trade-offs among pathogen development stages, apart from fast pathogen growth coninciding with fast hyperparasite growth. Also, the seemingly least fit pathogen strain was the most prevalent in the nature. CONCLUSIONS We conclude that in the nature environmental variation, and interactions with the antagonists of pathogens themselves may maintain variation in pathogen populations.
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Affiliation(s)
- Elina Numminen
- Department of Biosciences, University of Helsinki, Viikinkaari 1, PO Box 65, FI-00014, Helsinki, Finland.
| | - Elise Vaumourin
- Department of Biosciences, University of Helsinki, Viikinkaari 1, PO Box 65, FI-00014, Helsinki, Finland
| | - Steven R Parratt
- Department of Biosciences, University of Helsinki, Viikinkaari 1, PO Box 65, FI-00014, Helsinki, Finland.,University of Liverpool, Institute of Integrative Biology, Liverpool, L69 3BX, UK
| | - Lucie Poulin
- Department of Biosciences, University of Helsinki, Viikinkaari 1, PO Box 65, FI-00014, Helsinki, Finland.,Université de Nantes, Faculté des Sciences et des Techniques, Laboratoire de Biologie et de Pathologie Végétales (LBPV), EA 1157, SFR 4207 QUASAV, 2, rue de la Houssinière, BP 92 208, F-44322, Nantes Cedex 3, France
| | - Anna-Liisa Laine
- Department of Biosciences, University of Helsinki, Viikinkaari 1, PO Box 65, FI-00014, Helsinki, Finland.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
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2
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Kraemer SA, Boynton PJ. Evidence for microbial local adaptation in nature. Mol Ecol 2017; 26:1860-1876. [DOI: 10.1111/mec.13958] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/30/2016] [Accepted: 12/05/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Susanne A. Kraemer
- Ashworth Laboratories; University of Edinburgh; King's Buildings EH9 3FL Edinburgh UK
| | - Primrose J. Boynton
- Max Planck Institute for Evolutionary Biology; August-Thienemann-Str. 2 24306 Plön Germany
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3
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Roux F, Bergelson J. The Genetics Underlying Natural Variation in the Biotic Interactions of Arabidopsis thaliana: The Challenges of Linking Evolutionary Genetics and Community Ecology. Curr Top Dev Biol 2016; 119:111-56. [PMID: 27282025 DOI: 10.1016/bs.ctdb.2016.03.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the context of global change, predicting the responses of plant communities in an ever-changing biotic environment calls for a multipronged approach at the interface of evolutionary genetics and community ecology. However, our understanding of the genetic basis of natural variation involved in mediating biotic interactions, and associated adaptive dynamics of focal plants in their natural communities, is still in its infancy. Here, we review the genetic and molecular bases of natural variation in the response to biotic interactions (viruses, bacteria, fungi, oomycetes, herbivores, and plants) in the model plant Arabidopsis thaliana as well as the adaptive value of these bases. Among the 60 identified genes are a number that encode nucleotide-binding site leucine-rich repeat (NBS-LRR)-type proteins, consistent with early examples of plant defense genes. However, recent studies have revealed an extensive diversity in the molecular mechanisms of defense. Many types of genetic variants associate with phenotypic variation in biotic interactions, even among the genes of large effect that tend to be identified. In general, we found that (i) balancing selection rather than directional selection explains the observed patterns of genetic diversity within A. thaliana and (ii) the cost/benefit tradeoffs of adaptive alleles can be strongly dependent on both genomic and environmental contexts. Finally, because A. thaliana rarely interacts with only one biotic partner in nature, we highlight the benefit of exploring diffuse biotic interactions rather than tightly associated host-enemy pairs. This challenge would help to improve our understanding of coevolutionary quantitative genetics within the context of realistic community complexity.
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Affiliation(s)
- F Roux
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, Castanet-Tolosan, France.
| | - J Bergelson
- University of Chicago, Chicago, IL, United States
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Penczykowski RM, Laine A, Koskella B. Understanding the ecology and evolution of host-parasite interactions across scales. Evol Appl 2016; 9:37-52. [PMID: 27087838 PMCID: PMC4780374 DOI: 10.1111/eva.12294] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/18/2015] [Indexed: 12/19/2022] Open
Abstract
Predicting the emergence, spread and evolution of parasites within and among host populations requires insight to both the spatial and temporal scales of adaptation, including an understanding of within-host up through community-level dynamics. Although there are very few pathosystems for which such extensive data exist, there has been a recent push to integrate studies performed over multiple scales or to simultaneously test for dynamics occurring across scales. Drawing on examples from the literature, with primary emphasis on three diverse host-parasite case studies, we first examine current understanding of the spatial structure of host and parasite populations, including patterns of local adaptation and spatial variation in host resistance and parasite infectivity. We then explore the ways to measure temporal variation and dynamics in host-parasite interactions and discuss the need to examine change over both ecological and evolutionary timescales. Finally, we highlight new approaches and syntheses that allow for simultaneous analysis of dynamics across scales. We argue that there is great value in examining interplay among scales in studies of host-parasite interactions.
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Affiliation(s)
- Rachel M. Penczykowski
- Department of BiosciencesMetapopulation Research CentreUniversity of HelsinkiHelsinkiFinland
| | - Anna‐Liisa Laine
- Department of BiosciencesMetapopulation Research CentreUniversity of HelsinkiHelsinkiFinland
| | - Britt Koskella
- BiosciencesUniversity of ExeterTremoughUK
- Integrative BiologyUniversity of CaliforniaBerkeleyUSA
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5
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Carlsson-Granér U, Thrall PH. Host resistance and pathogen infectivity in host populations with varying connectivity. Evolution 2015; 69:926-38. [DOI: 10.1111/evo.12631] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 02/18/2015] [Indexed: 01/28/2023]
Affiliation(s)
- Ulla Carlsson-Granér
- Department of Ecology and Environmental Sciences; University of Umeå; S-90187 Umeå Sweden
| | - Peter H. Thrall
- CSIRO Agriculture Flagship GPO Box 1600; Canberra ACT 2601 Australia
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Laine AL, Burdon JJ, Nemri A, Thrall PH. Host ecotype generates evolutionary and epidemiological divergence across a pathogen metapopulation. Proc Biol Sci 2015; 281:rspb.2014.0522. [PMID: 24870042 DOI: 10.1098/rspb.2014.0522] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The extent and speed at which pathogens adapt to host resistance varies considerably. This presents a challenge for predicting when--and where--pathogen evolution may occur. While gene flow and spatially heterogeneous environments are recognized to be critical for the evolutionary potential of pathogen populations, we lack an understanding of how the two jointly shape coevolutionary trajectories between hosts and pathogens. The rust pathogen Melampsora lini infects two ecotypes of its host plant Linum marginale that occur in close proximity yet in distinct populations and habitats. In this study, we found that within-population epidemics were different between the two habitats. We then tested for pathogen local adaptation at host population and ecotype level in a reciprocal inoculation study. Even after controlling for the effect of spatial structure on infection outcome, we found strong evidence of pathogen adaptation at the host ecotype level. Moreover, sequence analysis of two pathogen infectivity loci revealed strong genetic differentiation by host ecotype but not by distance. Hence, environmental variation can be a key determinant of pathogen population genetic structure and coevolutionary dynamics and can generate strong asymmetry in infection risks through space.
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Affiliation(s)
- Anna-Liisa Laine
- Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65, Helsinki 00014, Finland
| | - Jeremy J Burdon
- CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory 2601, Australia
| | - Adnane Nemri
- CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory 2601, Australia
| | - Peter H Thrall
- CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory 2601, Australia
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Barrett LG, Encinas-Viso F, Burdon JJ, Thrall PH. Specialization for resistance in wild host-pathogen interaction networks. FRONTIERS IN PLANT SCIENCE 2015; 6:761. [PMID: 26442074 PMCID: PMC4585140 DOI: 10.3389/fpls.2015.00761] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 09/04/2015] [Indexed: 05/05/2023]
Abstract
Properties encompassed by host-pathogen interaction networks have potential to give valuable insight into the evolution of specialization and coevolutionary dynamics in host-pathogen interactions. However, network approaches have been rarely utilized in previous studies of host and pathogen phenotypic variation. Here we applied quantitative analyses to eight networks derived from spatially and temporally segregated host (Linum marginale) and pathogen (Melampsora lini) populations. First, we found that resistance strategies are highly variable within and among networks, corresponding to a spectrum of specialist and generalist resistance types being maintained within all networks. At the individual level, specialization was strongly linked to partial resistance, such that partial resistance was effective against a greater number of pathogens compared to full resistance. Second, we found that all networks were significantly nested. There was little support for the hypothesis that temporal evolutionary dynamics may lead to the development of nestedness in host-pathogen infection networks. Rather, the common patterns observed in terms of nestedness suggests a universal driver (or multiple drivers) that may be independent of spatial and temporal structure. Third, we found that resistance networks were significantly modular in two spatial networks, clearly reflecting spatial and ecological structure within one of the networks. We conclude that (1) overall patterns of specialization in the networks we studied mirror evolutionary trade-offs with the strength of resistance; (2) that specific network architecture can emerge under different evolutionary scenarios; and (3) network approaches offer great utility as a tool for probing the evolutionary and ecological genetics of host-pathogen interactions.
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Affiliation(s)
- Luke G. Barrett
- Commonwealth Scientific and Industrial Research Organization Agriculture FlagshipCanberra, ACT, Australia
- *Correspondence: Luke G. Barrett, Commonwealth Scientific and Industrial Research Organization Agriculture Flagship, GPO Box 1600, Canberra ACT 2601, Australia
| | - Francisco Encinas-Viso
- Centre for Australian National Biodiversity Research, Commonwealth Scientific and Industrial Research OrganizationCanberra, ACT, Australia
| | - Jeremy J. Burdon
- Commonwealth Scientific and Industrial Research Organization Agriculture FlagshipCanberra, ACT, Australia
| | - Peter H. Thrall
- Commonwealth Scientific and Industrial Research Organization Agriculture FlagshipCanberra, ACT, Australia
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8
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Schuck S, Weinhold A, Luu VT, Baldwin IT. Isolating fungal pathogens from a dynamic disease outbreak in a native plant population to establish plant-pathogen bioassays for the ecological model plant Nicotiana attenuata. PLoS One 2014; 9:e102915. [PMID: 25036191 PMCID: PMC4103856 DOI: 10.1371/journal.pone.0102915] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/25/2014] [Indexed: 11/19/2022] Open
Abstract
The wild tobacco species Nicotiana attenuata has been intensively used as a model plant to study its interaction with insect herbivores and pollinators in nature, however very little is known about its native pathogen community. We describe a fungal disease outbreak in a native N. attenuata population comprising 873 plants growing in an area of about 1500 m2. The population was divided into 14 subpopulations and disease symptom development in the subpopulations was monitored for 16 days, revealing a waxing and waning of visible disease symptoms with some diseased plants recovering fully. Native fungal N. attenuata pathogens were isolated from diseased plants, characterized genetically, chemotaxonomically and morphologically, revealing several isolates of the ascomycete genera Fusarium and Alternaria, that differed in the type and strength of the disease symptoms they caused in bioassays on either detached leaves or intact soil-grown plants. These isolates and the bioassays will empower the study of N. attenuata-pathogen interactions in a realistic ecological context.
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Affiliation(s)
- Stefan Schuck
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Arne Weinhold
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Van Thi Luu
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Ian T. Baldwin
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
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9
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Karasov TL, Horton MW, Bergelson J. Genomic variability as a driver of plant-pathogen coevolution? CURRENT OPINION IN PLANT BIOLOGY 2014; 18:24-30. [PMID: 24491596 PMCID: PMC4696489 DOI: 10.1016/j.pbi.2013.12.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/16/2013] [Accepted: 12/20/2013] [Indexed: 05/03/2023]
Abstract
Pathogens apply one of the strongest selective pressures in plant populations. Understanding plant-pathogen coevolution has therefore been a major research focus for at least sixty years [1]. Recent comparative genomic studies have revealed that the genes involved in plant defense and pathogen virulence are among the most polymorphic in the respective genomes. Which fraction of this diversity influences the host-pathogen interaction? Do coevolutionary dynamics maintain variation? Here we review recent literature on the evolutionary and molecular processes that shape this variation, focusing primarily on gene-for-gene interactions. In summarizing theoretical and empirical studies of the processes that shape this variation in natural plant and pathogen populations, we find a disconnect between the complexity of ecological interactions involving hosts and their myriad microbes, and the models that describe them.
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Affiliation(s)
- Talia L Karasov
- University of Chicago, Chicago, IL 60637, USA; Committee on Genetics, Genomics and Systems Biology
| | | | - Joy Bergelson
- University of Chicago, Chicago, IL 60637, USA; Department of Ecology & Evolution.
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10
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Nemri A, Saunders DGO, Anderson C, Upadhyaya NM, Win J, Lawrence GJ, Jones DA, Kamoun S, Ellis JG, Dodds PN. The genome sequence and effector complement of the flax rust pathogen Melampsora lini. FRONTIERS IN PLANT SCIENCE 2014; 5:98. [PMID: 24715894 PMCID: PMC3970004 DOI: 10.3389/fpls.2014.00098] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 02/28/2014] [Indexed: 05/18/2023]
Abstract
Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed most extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp). Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimize parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analyzed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote infection on their hosts.
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Affiliation(s)
| | | | - Claire Anderson
- Research School of Biological Sciences, College of Medicine, Biology and Environment, Australian National UniversityCanberra, ACT, Australia
| | | | - Joe Win
- The Sainsbury Laboratory, Norwich Research ParkNorwich, UK
| | | | - David A. Jones
- Research School of Biological Sciences, College of Medicine, Biology and Environment, Australian National UniversityCanberra, ACT, Australia
| | - Sophien Kamoun
- The Sainsbury Laboratory, Norwich Research ParkNorwich, UK
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García-Guzmán G, Heil M. Life histories of hosts and pathogens predict patterns in tropical fungal plant diseases. THE NEW PHYTOLOGIST 2014; 201:1106-1120. [PMID: 24171899 DOI: 10.1111/nph.12562] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 09/19/2013] [Indexed: 05/26/2023]
Abstract
Plant pathogens affect the fitness of their hosts and maintain biodiversity. However, we lack theories to predict the type and intensity of infections in wild plants. Here we demonstrate using fungal pathogens of tropical plants that an examination of the life histories of hosts and pathogens can reveal general patterns in their interactions. Fungal infections were more commonly reported for light-demanding than for shade-tolerant species and for evergreen rather than for deciduous hosts. Both patterns are consistent with classical defence theory, which predicts lower resistance in fast-growing species and suggests that the deciduous habit can reduce enemy populations. In our literature survey, necrotrophs were found mainly to infect shade-tolerant woody species whereas biotrophs dominated in light-demanding herbaceous hosts. Far-red signalling and its inhibitory effects on jasmonic acid signalling are likely to explain this phenomenon. Multiple changes between the necrotrophic and the symptomless endophytic lifestyle at the ecological and evolutionary scale indicate that endophytes should be considered when trying to understand large-scale patterns in the fungal infections of plants. Combining knowledge about the molecular mechanisms of pathogen resistance with classical defence theory enables the formulation of testable predictions concerning general patterns in the infections of wild plants by fungal pathogens.
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Affiliation(s)
| | - Martin Heil
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados (CINVESTAV), Irapuato, Guanajuato, México
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Haag KL, Sheikh-Jabbari E, Ben-Ami F, Ebert D. Microsatellite and single-nucleotide polymorphisms indicate recurrent transitions to asexuality in a microsporidian parasite. J Evol Biol 2013; 26:1117-28. [PMID: 23530861 DOI: 10.1111/jeb.12125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 01/07/2013] [Indexed: 01/10/2023]
Abstract
Assessing the mode of reproduction of microparasites remains a difficult task because direct evidence for sexual processes is often absent and the biological covariates of sex and asex are poorly known. Species with geographically divergent modes of reproduction offer the possibility to explore some of these covariates, for example, the influence of life-history traits, mode of transmission and life-cycle complexity. Here, we present a phylogeographical study of a microsporidian parasite, which allows us to relate population genetic structure and mode of reproduction to its geographically diverged life histories. We show that in microsporidians from the genus Hamiltosporidium, that use the cladoceran Daphnia as host, an epidemic population structure has evolved, most probably since the last Ice Age. We partially sequenced three housekeeping genes (alpha tubulin, beta tubulin and hsp70) and genotyped seven microsatellite loci in 51 Hamiltosporidium isolates sampled within Europe and the Middle East. We found two phylogenetically related asexual parasite lines, one each from Fennoscandia and Israel, which share the unique ability of being transmitted both vertically and horizontally from Daphnia to Daphnia. The sexual forms cannot transmit horizontally among Daphnia, but presumably have a complex life cycle with a second host species. In spite of the similarities between the two asexual lineages, a clustering analysis based on microsatellite polymorphisms shows that asexual Fennoscandian parasites do not share ancestry with any other Hamiltosporidium that we have sampled. Moreover, allele sequence divergence at the hsp70 locus is twice as large in Fennoscandian than in Israeli parasites. Our results indicate that asexual reproduction evolved twice independently, first in Fennoscandian and more recently in the Israeli parasites. We conclude that the independent origin of asexuality in these two populations is associated with the altered parasite mode of transmission and the underlying dynamics of host populations.
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Affiliation(s)
- K L Haag
- Zoological Institute, University of Basel, Basel, Switzerland
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