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Carvalho T, Belasen AM, Toledo LF, James TY. Coevolution of a generalist pathogen with many hosts: the case of the amphibian chytrid Batrachochytrium dendrobatidis. Curr Opin Microbiol 2024; 78:102435. [PMID: 38387210 DOI: 10.1016/j.mib.2024.102435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 12/22/2023] [Accepted: 01/21/2024] [Indexed: 02/24/2024]
Abstract
Generalist pathogens maintain infectivity in numerous hosts; how this broad ecological niche impacts host-pathogen coevolution remains to be widely explored. Batrachochytrium dendrobatidis (Bd) is a highly generalist pathogenic fungus that has caused devastating declines in hundreds of amphibian species worldwide. This review examines amphibian chytridiomycosis host-pathogen interactions and available evidence for coevolution between Bd and its numerous hosts. We summarize recent evidence showing that Bd genotypes vary in geographic distribution and virulence, and that amphibian species also vary in Bd susceptibility according to their geographic distribution. How much variation can be explained by phenotypic plasticity or genetic differences remains uncertain. Recent research suggests that Bd genotypes display preferences for specific hosts and that some hosts are undergoing evolution as populations rebound from Bd outbreaks. Taken together, these findings suggest the potential for coevolution to occur and illuminate a path for addressing open questions through integrating historical and contemporary genetic data.
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Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Anat M Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, United States
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States.
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2
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Hu Y, Wang X, Xu Y, Yang H, Tong Z, Tian R, Xu S, Yu L, Guo Y, Shi P, Huang S, Yang G, Shi S, Wei F. Molecular mechanisms of adaptive evolution in wild animals and plants. SCIENCE CHINA. LIFE SCIENCES 2023; 66:453-495. [PMID: 36648611 PMCID: PMC9843154 DOI: 10.1007/s11427-022-2233-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 08/30/2022] [Indexed: 01/18/2023]
Abstract
Wild animals and plants have developed a variety of adaptive traits driven by adaptive evolution, an important strategy for species survival and persistence. Uncovering the molecular mechanisms of adaptive evolution is the key to understanding species diversification, phenotypic convergence, and inter-species interaction. As the genome sequences of more and more non-model organisms are becoming available, the focus of studies on molecular mechanisms of adaptive evolution has shifted from the candidate gene method to genetic mapping based on genome-wide scanning. In this study, we reviewed the latest research advances in wild animals and plants, focusing on adaptive traits, convergent evolution, and coevolution. Firstly, we focused on the adaptive evolution of morphological, behavioral, and physiological traits. Secondly, we reviewed the phenotypic convergences of life history traits and responding to environmental pressures, and the underlying molecular convergence mechanisms. Thirdly, we summarized the advances of coevolution, including the four main types: mutualism, parasitism, predation and competition. Overall, these latest advances greatly increase our understanding of the underlying molecular mechanisms for diverse adaptive traits and species interaction, demonstrating that the development of evolutionary biology has been greatly accelerated by multi-omics technologies. Finally, we highlighted the emerging trends and future prospects around the above three aspects of adaptive evolution.
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Affiliation(s)
- Yibo Hu
- CAS Key Lab of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Xiaoping Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Yongchao Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hui Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
| | - Zeyu Tong
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Ran Tian
- College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Shaohua Xu
- State Key Laboratory of Biocontrol, Guangdong Key Lab of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Li Yu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, 650091, China.
| | - Yalong Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Peng Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China.
| | - Shuangquan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| | - Guang Yang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
- College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
| | - Suhua Shi
- State Key Laboratory of Biocontrol, Guangdong Key Lab of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Fuwen Wei
- CAS Key Lab of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
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3
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Duhamel M, Carpentier F, Begerow D, Hood ME, Rodríguez de la Vega RC, Giraud T. Onset and stepwise extensions of recombination suppression are common in mating-type chromosomes of Microbotryum anther-smut fungi. J Evol Biol 2022; 35:1619-1634. [PMID: 35271741 PMCID: PMC10078771 DOI: 10.1111/jeb.13991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/21/2021] [Accepted: 02/07/2022] [Indexed: 12/16/2022]
Abstract
Sex chromosomes and mating-type chromosomes can display large genomic regions without recombination. Recombination suppression often extended stepwise with time away from the sex- or mating-type-determining genes, generating evolutionary strata of differentiation between alternative sex or mating-type chromosomes. In anther-smut fungi of the Microbotryum genus, recombination suppression evolved repeatedly, linking the two mating-type loci and extended multiple times in regions distal to the mating-type genes. Here, we obtained high-quality genome assemblies of alternative mating types for four Microbotryum fungi. We found an additional event of independent chromosomal rearrangements bringing the two mating-type loci on the same chromosome followed by recombination suppression linking them. We also found, in a new clade analysed here, that recombination suppression between the two mating-type loci occurred in several steps, with first an ancestral recombination suppression between one of the mating-type locus and its centromere; later, completion of recombination suppression up to the second mating-type locus occurred independently in three species. The estimated dates of recombination suppression between the mating-type loci ranged from 0.15 to 3.58 million years ago. In total, this makes at least nine independent events of linkage between the mating-type loci across the Microbotryum genus. Several mating-type locus linkage events occurred through the same types of chromosomal rearrangements, where similar chromosome fissions at centromeres represent convergence in the genomic changes leading to the phenotypic convergence. These findings further highlight Microbotryum fungi as excellent models to study the evolution of recombination suppression.
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Affiliation(s)
- Marine Duhamel
- Ecologie Systématique Evolution, Bâtiment 360CNRSAgroParisTechUniversité Paris‐SaclayOrsayFrance
- Evolution der Pflanzen und PilzeRuhr‐Universität BochumBochumGermany
| | - Fantin Carpentier
- Ecologie Systématique Evolution, Bâtiment 360CNRSAgroParisTechUniversité Paris‐SaclayOrsayFrance
| | - Dominik Begerow
- Evolution der Pflanzen und PilzeRuhr‐Universität BochumBochumGermany
| | | | | | - Tatiana Giraud
- Ecologie Systématique Evolution, Bâtiment 360CNRSAgroParisTechUniversité Paris‐SaclayOrsayFrance
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4
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Bazzicalupo A. Local adaptation in fungi. FEMS Microbiol Rev 2022; 46:6604384. [PMID: 35675293 DOI: 10.1093/femsre/fuac026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/24/2022] [Accepted: 05/30/2022] [Indexed: 01/09/2023] Open
Abstract
In this review, I explore the pervasive but underappreciated role of local adaptation in fungi. It has been difficult historically to study local adaptation in fungi because of the limited understanding of fungal species and their traits, but new hope has been offered with technological advances in sequencing. The filamentous nature of fungi invalidates some assumptions made in evolution because of their ability to exist as multinucleate entities with genetically different nuclei sharing the same cytoplasm. Many insights on local adaptation have come from studying fungi, and much of the empirical evidence gathered about local adaptation in the context of host-pathogen interactions comes from studying fungal virulence genes, drug resistance, and environmental adaptation. Together, these insights paint a picture of the variety of processes involved in fungal local adaptation and their connections to the unusual cell biology of Fungi (multinucleate, filamentous habit), but there is much that remains unknown, with major gaps in our knowledge of fungal species, their phenotypes, and the ways by which they adapt to local conditions.
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Affiliation(s)
- Anna Bazzicalupo
- Department of Zoology, University of British Columbia, 4200 - 6270 University Blvd., Vancouver V6T 1Z4, Canada
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5
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Silan E, Ozkilinc H. Phylogenetic divergences in brown rot fungal pathogens of Monilinia species from a worldwide collection: inferences based on the nuclear versus mitochondrial genes. BMC Ecol Evol 2022; 22:119. [PMID: 36271324 PMCID: PMC9585774 DOI: 10.1186/s12862-022-02079-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Phylogenetic analyses for plant pathogenic fungi explore many questions on diversities, relationships, origins, and divergences of populations from different sources such as species, host, and geography. This information is highly valuable, especially from a large global sampling, to understand the evolutionary paths of the pathogens worldwide. Monilinia fructicola and M. laxa are two important fungal pathogens of stone fruits that cause the widespread disease commonly known as brown rot. Three nuclear genes (Calmodulin, SDHA, TEF1α) and three mitochondrial genes (Cytochrome_b, NAD2, and NAD5) of the two pathogen species from a worldwide collection including five different countries from four different continents were studied in this work. RESULTS Both Maximum Likelihood and Bayesian approaches were applied to the data sets, and in addition, Maximum Parsimony based approaches were used for the regions having indel polymorphisms. Calmodulin, SDHA, NAD2, and NAD5 regions were found phylogenetically informative and utilized for phylogenetics of Monilinia species for the first time. Each gene region presented a set of haplotypes except Cytochrome_b, which was monomorphic. According to this large collection of two Monilinia species around the world, M. fructicola showed more diversity than M. laxa, a result that should be carefully considered, as M. fructicola is known to be a quarantine pathogen. Moreover, the other two mitochondrial genes (NAD2 and NAD5) did not have any substitution type mutations but presented an intron indel polymorphism indicating the contribution of introns as well as mobile introns to the fungal diversity and evolution. Based on the concatenated gene sets, nuclear DNA carries higher mutations and uncovers more phylogenetic clusters in comparison to the mitochondrial DNA-based data for these fungal species. CONCLUSIONS This study provides the most comprehensive knowledge on the phylogenetics of both nuclear and mitochondrial genes of two prominent brown rot pathogens, M. fructicola and M. laxa. Based on the regions used in this study, the nuclear genes resolved phylogenetic branching better than the mitochondrial genes and discovered new phylogenetic lineages for these species.
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Affiliation(s)
- Ece Silan
- School of Graduate Studies, MSc Program in Biomolecular Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Hilal Ozkilinc
- School of Graduate Studies, MSc Program in Biomolecular Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey.
- Dept. of Molecular Biology and Genetics, Faculty of Science, Çanakkale Onsekiz Mart University, Çanakkale, Turkey.
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6
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Disease‐mediated nutrient dynamics: Coupling host‐pathogen interactions with ecosystem elements and energy. ECOL MONOGR 2022. [DOI: 10.1002/ecm.1510] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Lerner N, Luizzi V, Antonovics J, Bruns E, Hood ME. Resistance Correlations Influence Infection by Foreign Pathogens. Am Nat 2021; 198:206-218. [PMID: 34260867 PMCID: PMC8283004 DOI: 10.1086/715013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
AbstractReciprocal selection promotes the specificity of host-pathogen associations and resistance polymorphisms in response to disease. However, plants and animals also vary in response to pathogen species not previously encountered in nature, with potential effects on new disease emergence. Using anther smut disease, we show that resistance (measured as infection rates) to foreign pathogens can be correlated with standing variation in resistance to an endemic pathogen. In Silene vulgaris, genetic variation in resistance to its endemic anther smut pathogen correlated positively with resistance variation to an anther smut pathogen from another host, but the relationship was negative between anther smut and a necrotrophic pathogen. We present models describing the genetic basis for assessing resistance relationships between endemic and foreign pathogens and for quantifying infection probabilities on foreign pathogen introduction. We show that even when the foreign pathogen has a lower average infection ability than the endemic pathogen, infection outcomes are determined by the sign and strength of the regression of the host's genetic variation in infection rates by a foreign pathogen on variation in infection rates by an endemic pathogen as well as by resistance allele frequencies. Given that preinvasion equilibria of resistance are determined by factors including resistance costs, we show that protection against foreign pathogens afforded by positively correlated resistances can be lessened or even result in elevated infection risk at the population level, depending on local dynamics. Therefore, a pathogen's emergence potential could be influenced not only by its average infection rate but also by resistance variation resulting from prior selection imposed by endemic diseases.
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Affiliation(s)
- Noah Lerner
- Department of Biology, Amherst College, Amherst, Massachusetts 01002
| | - Victoria Luizzi
- Department of Biology, Amherst College, Amherst, Massachusetts 01002
| | - Janis Antonovics
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Emily Bruns
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | - Michael E. Hood
- Department of Biology, Amherst College, Amherst, Massachusetts 01002
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8
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Walters SJ, Robinson TP, Byrne M, Wardell‐Johnson GW, Nevill P. Association of putatively adaptive genetic variation with climatic variables differs between a parasite and its host. Evol Appl 2021; 14:1732-1746. [PMID: 34295360 PMCID: PMC8288004 DOI: 10.1111/eva.13234] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 11/28/2022] Open
Abstract
Parasitism is a pervasive phenomenon in nature with the relationship between species driving evolution in both parasite and host. Due to their host-dependent lifestyle, parasites may adapt to the abiotic environment in ways that differ from their hosts or from free-living relatives; yet rarely has this been assessed. Here, we test two competing hypotheses related to whether putatively adaptive genetic variation in a specialist mistletoe associates with the same, or different, climatic variables as its host species. We sampled 11 populations of the specialist mistletoe Amyema gibberula var. tatei (n = 154) and 10 populations of its associated host Hakea recurva subsp. recurva (n = 160). Reduced-representation sequencing was used to obtain genome-wide markers and putatively adaptive variation detected using genome scan methods. Climate associations were identified using generalized dissimilarity modelling, and these were mapped geographically to visualize the spatial patterns of genetic composition. Our results supported the hypothesis of parasites and host species responding differently to climatic variables. Temperature was relatively more important in predicting allelic turnover in the specialist mistletoe while precipitation was more important for the host. This suggests that parasitic plants and host species may respond differently to selective pressures, potentially as a result of differing nutrient acquisition strategies. Specifically, mistletoes acquire water from hosts (rather than the abiotic environment), which may provide a buffer to precipitation as a selective pressure. This work deepens and complements the physiological and other ecological studies of adaptation and provides a window into the evolutionary processes that underlie previously observed phenomena. Applying these methods to a comparative study in a host-parasite system has also highlighted factors that affect the study of selection pressure on nonmodel organisms, such as differing adaptation rates and lack of reference genomes.
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Affiliation(s)
- Sheree J. Walters
- ARC Centre for Mine Site RestorationSchool of Molecular and Life SciencesCurtin UniversityBentleyWAAustralia
| | - Todd P. Robinson
- School of Earth and Planetary ScienceCurtin UniversityBentleyWAAustralia
| | - Margaret Byrne
- Biodiversity and Conservation ScienceDepartment of Biodiversity, Conservation and AttractionsBentleyWAAustralia
- School of Molecular and Life SciencesCurtin UniversityBentleyWAAustralia
| | - Grant W. Wardell‐Johnson
- ARC Centre for Mine Site RestorationSchool of Molecular and Life SciencesCurtin UniversityBentleyWAAustralia
| | - Paul Nevill
- ARC Centre for Mine Site RestorationSchool of Molecular and Life SciencesCurtin UniversityBentleyWAAustralia
- Trace and Environmental DNA LaboratorySchool of Molecular and Life SciencesCurtin UniversityBentleyWAAustralia
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9
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Boekhout T, Aime MC, Begerow D, Gabaldón T, Heitman J, Kemler M, Khayhan K, Lachance MA, Louis EJ, Sun S, Vu D, Yurkov A. The evolving species concepts used for yeasts: from phenotypes and genomes to speciation networks. FUNGAL DIVERS 2021; 109:27-55. [PMID: 34720775 PMCID: PMC8550739 DOI: 10.1007/s13225-021-00475-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
Here we review how evolving species concepts have been applied to understand yeast diversity. Initially, a phenotypic species concept was utilized taking into consideration morphological aspects of colonies and cells, and growth profiles. Later the biological species concept was added, which applied data from mating experiments. Biophysical measurements of DNA similarity between isolates were an early measure that became more broadly applied with the advent of sequencing technology, leading to a sequence-based species concept using comparisons of parts of the ribosomal DNA. At present phylogenetic species concepts that employ sequence data of rDNA and other genes are universally applied in fungal taxonomy, including yeasts, because various studies revealed a relatively good correlation between the biological species concept and sequence divergence. The application of genome information is becoming increasingly common, and we strongly recommend the use of complete, rather than draft genomes to improve our understanding of species and their genome and genetic dynamics. Complete genomes allow in-depth comparisons on the evolvability of genomes and, consequently, of the species to which they belong. Hybridization seems a relatively common phenomenon and has been observed in all major fungal lineages that contain yeasts. Note that hybrids may greatly differ in their post-hybridization development. Future in-depth studies, initially using some model species or complexes may shift the traditional species concept as isolated clusters of genetically compatible isolates to a cohesive speciation network in which such clusters are interconnected by genetic processes, such as hybridization.
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Affiliation(s)
- Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | - M. Catherine Aime
- Dept Botany and Plant Pathology, College of Agriculture, Purdue University, West Lafayette, IN 47907 USA
| | - Dominik Begerow
- Evolution of Plants and Fungi, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC–CNS), Jordi Girona, 29, 08034 Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710 USA
| | - Martin Kemler
- Evolution of Plants and Fungi, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Kantarawee Khayhan
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, 56000 Thailand
| | - Marc-André Lachance
- Department of Biology, University of Western Ontario, London, ON N6A 5B7 Canada
| | - Edward J. Louis
- Department of Genetics and Genome Biology, Genetic Architecture of Complex Traits, University of Leicester, Leicester, LE1 7RH UK
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710 USA
| | - Duong Vu
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Andrey Yurkov
- German Collection of Microorganisms and Cell Cultures, Leibniz Institute DSMZ, Brunswick, Germany
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10
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Dutta A, Hartmann FE, Francisco CS, McDonald BA, Croll D. Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments. THE ISME JOURNAL 2021; 15:1402-1419. [PMID: 33452474 PMCID: PMC8115182 DOI: 10.1038/s41396-020-00859-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 02/06/2023]
Abstract
The adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen's ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.
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Affiliation(s)
- Anik Dutta
- grid.5801.c0000 0001 2156 2780Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Fanny E. Hartmann
- grid.5801.c0000 0001 2156 2780Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland ,grid.417885.70000 0001 2185 8223Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, AgroParisTech, 91400 Orsay, France
| | - Carolina Sardinha Francisco
- grid.5801.c0000 0001 2156 2780Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland ,Present Address: Environmental Genomics Group, Botanical Institute, CAU Kiel, Germany
| | - Bruce A. McDonald
- grid.5801.c0000 0001 2156 2780Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Daniel Croll
- grid.10711.360000 0001 2297 7718Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
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11
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Hartmann FE, Rodríguez de la Vega RC, Gladieux P, Ma WJ, Hood ME, Giraud T. Higher Gene Flow in Sex-Related Chromosomes than in Autosomes during Fungal Divergence. Mol Biol Evol 2020; 37:668-682. [PMID: 31651949 PMCID: PMC7038665 DOI: 10.1093/molbev/msz252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nonrecombining sex chromosomes are widely found to be more differentiated than autosomes among closely related species, due to smaller effective population size and/or to a disproportionally large-X effect in reproductive isolation. Although fungal mating-type chromosomes can also display large nonrecombining regions, their levels of differentiation compared with autosomes have been little studied. Anther-smut fungi from the Microbotryum genus are castrating pathogens of Caryophyllaceae plants with largely nonrecombining mating-type chromosomes. Using whole genome sequences of 40 fungal strains, we quantified genetic differentiation among strains isolated from the geographically overlapping North American species and subspecies of Silene virginica and S. caroliniana. We inferred that gene flow likely occurred at the early stages of divergence and then completely stopped. We identified large autosomal genomic regions with chromosomal inversions, with higher genetic divergence than the rest of the genomes and highly enriched in selective sweeps, supporting a role of rearrangements in preventing gene flow in genomic regions involved in ecological divergence. Unexpectedly, the nonrecombining mating-type chromosomes showed lower divergence than autosomes due to higher gene flow, which may be promoted by adaptive introgressions of less degenerated mating-type chromosomes. The fact that both mating-type chromosomes are always heterozygous and nonrecombining may explain such patterns that oppose to those found for XY or ZW sex chromosomes. The specific features of mating-type chromosomes may also apply to the UV sex chromosomes determining sexes at the haploid stage in algae and bryophytes and may help test general hypotheses on the evolutionary specificities of sex-related chromosomes.
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Affiliation(s)
- Fanny E Hartmann
- Ecologie Systematique Evolution, Batiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Ricardo C Rodríguez de la Vega
- Ecologie Systematique Evolution, Batiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Pierre Gladieux
- UMR BGPI, Univ Montpellier, INRA, CIRAD, Montpellier SupAgro, Montpellier, France
| | - Wen-Juan Ma
- Biology Department, Science Centre, Amherst College, Amherst, MA
| | - Michael E Hood
- Biology Department, Science Centre, Amherst College, Amherst, MA
| | - Tatiana Giraud
- Ecologie Systematique Evolution, Batiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
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12
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Floral fungal-bacterial community structure and co-occurrence patterns in four sympatric island plant species. Fungal Biol 2020; 125:49-61. [PMID: 33317776 DOI: 10.1016/j.funbio.2020.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 01/30/2023]
Abstract
Flowers' fungal and bacterial communities can exert great impacts on host plant wellness and reproductive success-both directly and indirectly through species interactions. However, information about community structure and co-occurrence patterns in floral microbiome remains scarce. Here, using culture-independent methods, we investigated fungal and bacterial communities associated with stamens and pistils of four plant species (Scaevola taccada, Ipomoea cairica, Ipomoea pes-caprae, and Mussaenda kwangtungensis) growing together under the same environment conditions in an island located in South China. Plant species identity significantly influenced community composition of floral fungi but not bacteria. Stamen and pistil microbiomes did not differ in community composition, but differed in co-occurrence network topological features. Compared with the stamen network, pistil counterpart had fewer links between bacteria and fungi and showed more modular but less concentrated and connected structure. In addition, degree distribution of microbial network in each host species and each microhabitat (stamen or pistil) followed a significant power-law pattern. These results enhance our understanding in the assembly principles and ecological interactions of floral microbial communities.
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13
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Hartmann FE, Snirc A, Cornille A, Godé C, Touzet P, Van Rossum F, Fournier E, Le Prieur S, Shykoff J, Giraud T. Congruent population genetic structures and divergence histories in anther‐smut fungi and their host plants
Silene italica
and the
Silene nutans
species complex. Mol Ecol 2020; 29:1154-1172. [DOI: 10.1111/mec.15387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Fanny E. Hartmann
- Ecologie Systematique Evolution Batiment 360 AgroParisTech CNRS Universite Paris‐Saclay Orsay France
| | - Alodie Snirc
- Ecologie Systematique Evolution Batiment 360 AgroParisTech CNRS Universite Paris‐Saclay Orsay France
| | - Amandine Cornille
- Genetique Quantitative et Evolution–Le Moulon AgroParisTech CNRS INRAE Universite Paris‐Saclay Gif‐sur‐Yvette France
| | - Cécile Godé
- UMR 8198 ‐ Evo‐Eco‐Paleo CNRS Univ. Lille Lille France
| | - Pascal Touzet
- UMR 8198 ‐ Evo‐Eco‐Paleo CNRS Univ. Lille Lille France
| | - Fabienne Van Rossum
- Meise Botanic Garden Meise Belgium
- Fédération Wallonie–Bruxelles Brussels Belgium
| | | | - Stéphanie Le Prieur
- Ecologie Systematique Evolution Batiment 360 AgroParisTech CNRS Universite Paris‐Saclay Orsay France
| | - Jacqui Shykoff
- Ecologie Systematique Evolution Batiment 360 AgroParisTech CNRS Universite Paris‐Saclay Orsay France
| | - Tatiana Giraud
- Ecologie Systematique Evolution Batiment 360 AgroParisTech CNRS Universite Paris‐Saclay Orsay France
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Cause and Effectors: Whole-Genome Comparisons Reveal Shared but Rapidly Evolving Effector Sets among Host-Specific Plant-Castrating Fungi. mBio 2019; 10:mBio.02391-19. [PMID: 31690676 PMCID: PMC6831777 DOI: 10.1128/mbio.02391-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Plant pathogens use molecular weapons to successfully infect their hosts, secreting a large portfolio of various proteins and enzymes. Different plant species are often parasitized by host-specific pathogens; however, it is still unclear whether the molecular basis of such host specialization involves species-specific weapons or different variants of the same weapons. We therefore compared the genes encoding secreted proteins in three plant-castrating pathogens parasitizing different host plants, producing their spores in plant anthers by replacing pollen. We validated our predictions for secretion signals for some genes and checked that our predicted secreted proteins were often highly expressed during plant infection. While we found few species-specific secreted proteins, numerous genes encoding secreted proteins showed signs of rapid evolution and of natural selection. Our study thus found that most changes among closely related host-specific pathogens involved rapid adaptive changes in shared molecular weapons rather than innovations for new weapons. Plant pathogens utilize a portfolio of secreted effectors to successfully infect and manipulate their hosts. It is, however, still unclear whether changes in secretomes leading to host specialization involve mostly effector gene gains/losses or changes in their sequences. To test these hypotheses, we compared the secretomes of three host-specific castrating anther smut fungi (Microbotryum), two being sister species. To address within-species evolution, which might involve coevolution and local adaptation, we compared the secretomes of strains from differentiated populations. We experimentally validated a subset of signal peptides. Secretomes ranged from 321 to 445 predicted secreted proteins (SPs), including a few species-specific proteins (42 to 75), and limited copy number variation, i.e., little gene family expansion or reduction. Between 52% and 68% of the SPs did not match any Pfam domain, a percentage that reached 80% for the small secreted proteins, indicating rapid evolution. In comparison to background genes, we indeed found SPs to be more differentiated among species and strains, more often under positive selection, and highly expressed in planta; repeat-induced point mutations (RIPs) had no role in effector diversification, as SPs were not closer to transposable elements than background genes and were not more RIP affected. Our study thus identified both conserved core proteins, likely required for the pathogenic life cycle of all Microbotryum species, and proteins that were species specific or evolving under positive selection; these proteins may be involved in host specialization and/or coevolution. Most changes among closely related host-specific pathogens, however, involved rapid changes in sequences rather than gene gains/losses.
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