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Gaikani HK, Stolar M, Kriti D, Nislow C, Giaever G. From beer to breadboards: yeast as a force for biological innovation. Genome Biol 2024; 25:10. [PMID: 38178179 PMCID: PMC10768129 DOI: 10.1186/s13059-023-03156-9] [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: 02/14/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
The history of yeast Saccharomyces cerevisiae, aka brewer's or baker's yeast, is intertwined with our own. Initially domesticated 8,000 years ago to provide sustenance to our ancestors, for the past 150 years, yeast has served as a model research subject and a platform for technology. In this review, we highlight many ways in which yeast has served to catalyze the fields of functional genomics, genome editing, gene-environment interaction investigation, proteomics, and bioinformatics-emphasizing how yeast has served as a catalyst for innovation. Several possible futures for this model organism in synthetic biology, drug personalization, and multi-omics research are also presented.
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Affiliation(s)
- Hamid Kian Gaikani
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Monika Stolar
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Divya Kriti
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Corey Nislow
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.
| | - Guri Giaever
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
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2
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Romanauska A, Köhler A. Lipid saturation controls nuclear envelope function. Nat Cell Biol 2023; 25:1290-1302. [PMID: 37591950 PMCID: PMC10495262 DOI: 10.1038/s41556-023-01207-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/18/2023] [Indexed: 08/19/2023]
Abstract
The nuclear envelope (NE) is a spherical double membrane with elastic properties. How NE shape and elasticity are regulated by lipid chemistry is unknown. Here we discover lipid acyl chain unsaturation as essential for NE and nuclear pore complex (NPC) architecture and function. Increased lipid saturation rigidifies the NE and the endoplasmic reticulum into planar, polygonal membranes, which are fracture prone. These membranes exhibit a micron-scale segregation of lipids into ordered and disordered phases, excluding NPCs from the ordered phase. Balanced lipid saturation is required for NPC integrity, pore membrane curvature and nucleocytoplasmic transport. Oxygen deprivation amplifies the impact of saturated lipids, causing NE rigidification and rupture. Conversely, lipid droplets buffer saturated lipids to preserve NE architecture. Our study uncovers a fundamental link between lipid acyl chain structure and the integrity of the cell nucleus with implications for nuclear membrane malfunction in ischaemic tissues.
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Affiliation(s)
- Anete Romanauska
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Center for Molecular Biology, University of Vienna, Vienna, Austria
| | - Alwin Köhler
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria.
- Center for Molecular Biology, University of Vienna, Vienna, Austria.
- Center for Medical Biochemistry, Medical University of Vienna, Vienna, Austria.
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3
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Zhao S, Martin-Vicente A, Colabardini AC, Pereira Silva L, Rinker DC, Fortwendel JR, Goldman GH, Gibbons JG. Genomic and Molecular Identification of Genes Contributing to the Caspofungin Paradoxical Effect in Aspergillus fumigatus. Microbiol Spectr 2022; 10:e0051922. [PMID: 36094204 PMCID: PMC9603777 DOI: 10.1128/spectrum.00519-22] [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: 02/09/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
Aspergillus fumigatus is a deadly opportunistic fungal pathogen responsible for ~100,000 annual deaths. Azoles are the first line antifungal agent used against A. fumigatus, but azole resistance has rapidly evolved making treatment challenging. Caspofungin is an important second-line therapy against invasive pulmonary aspergillosis, a severe A. fumigatus infection. Caspofungin functions by inhibiting β-1,3-glucan synthesis, a primary and essential component of the fungal cell wall. A phenomenon termed the caspofungin paradoxical effect (CPE) has been observed in several fungal species where at higher concentrations of caspofungin, chitin replaces β-1,3-glucan, morphology returns to normal, and growth rate increases. CPE appears to occur in vivo, and it is therefore clinically important to better understand the genetic contributors to CPE. We applied genomewide association (GWA) analysis and molecular genetics to identify and validate candidate genes involved in CPE. We quantified CPE across 67 clinical isolates and conducted three independent GWA analyses to identify genetic variants associated with CPE. We identified 48 single nucleotide polymorphisms (SNPs) associated with CPE. We used a CRISPR/Cas9 approach to generate gene deletion mutants for seven genes harboring candidate SNPs. Two null mutants, ΔAfu3g13230 and ΔAfu4g07080 (dscP), resulted in reduced basal growth rate and a loss of CPE. We further characterized the dscP phosphatase-null mutant and observed a significant reduction in conidia production and extremely high sensitivity to caspofungin at both low and high concentrations. Collectively, our work reveals the contribution of Afu3g13230 and dscP in CPE and sheds new light on the complex genetic interactions governing this phenotype. IMPORTANCE This is one of the first studies to apply genomewide association (GWA) analysis to identify genes involved in an Aspergillus fumigatus phenotype. A. fumigatus is an opportunistic fungal pathogen that causes hundreds of thousands of infections and ~100,000 deaths each year, and antifungal resistance has rapidly evolved in this species. A phenomenon called the caspofungin paradoxical effect (CPE) occurs in some isolates, where high concentrations of the drug lead to increased growth rate. There is clinical relevance in understanding the genetic basis of this phenotype, since caspofungin concentrations could lead to unintended adverse clinical outcomes in certain cases. Using GWA analysis, we identified several interesting candidate polymorphisms and genes and then generated gene deletion mutants to determine whether these genes were important for CPE. Two of these mutant strains (ΔAfu3g13230 and ΔAfu4g07080/ΔdscP) displayed a loss of the CPE. This study sheds light on the genes involved in clinically important phenotype CPE.
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Affiliation(s)
- Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Lilian Pereira Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - David C. Rinker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - John G. Gibbons
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
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4
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Peter J, Friedrich A, Liti G, Schacherer J. Extensive simulations assess the performance of genome-wide association mapping in various
Saccharomyces cerevisiae
subpopulations. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200514. [PMID: 35634920 PMCID: PMC9149792 DOI: 10.1098/rstb.2020.0514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
With the advent of high throughput sequencing technologies, genome-wide association studies (GWAS) have become a powerful paradigm for dissecting the genetic origins of the observed phenotypic variation. We recently completely sequenced the genome of 1011 Saccharomyces cerevisiae isolates, laying a strong foundation for GWAS. To assess the feasibility and the limits of this approach, we performed extensive simulations using five selected subpopulations as well as the total set of 1011 genomes. We measured the ability to detect the causal genetic variants involved in Mendelian and more complex traits using a linear mixed model approach. The results showed that population structure is well accounted for and is not the main problem when the sample size is high enough. While the genetic determinant of a Mendelian trait is easily mapped in all studied subpopulations, discrepancies are seen between datasets when performing GWAS on a complex trait in terms of detection, false positive and false negative rate. Finally, we performed GWAS on the different defined subpopulations using a real quantitative trait (resistance to copper sulfate) and showed the feasibility of this approach. The performance of each dataset depends simultaneously on several factors such as sample size, relatedness and population evolutionary history. This article is part of the theme issue ‘Genetic basis of adaptation and speciation: from loci to causative mutations’.
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Affiliation(s)
- Jackson Peter
- Université de Strasbourg, CNRS, GMGM UMR 7156, Strasbourg, France
| | - Anne Friedrich
- Université de Strasbourg, CNRS, GMGM UMR 7156, Strasbourg, France
| | - Gianni Liti
- Université Côte d'Azur, CNRS, INSERM, IRCAN, Nice, France
| | - Joseph Schacherer
- Université de Strasbourg, CNRS, GMGM UMR 7156, Strasbourg, France
- Institut Universitaire de France (IUF), Paris, France
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5
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O’Brien CE, Oliveira-Pacheco J, Ó Cinnéide E, Haase MAB, Hittinger CT, Rogers TR, Zaragoza O, Bond U, Butler G. Population genomics of the pathogenic yeast Candida tropicalis identifies hybrid isolates in environmental samples. PLoS Pathog 2021; 17:e1009138. [PMID: 33788904 PMCID: PMC8041210 DOI: 10.1371/journal.ppat.1009138] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/12/2021] [Accepted: 03/15/2021] [Indexed: 01/02/2023] Open
Abstract
Candida tropicalis is a human pathogen that primarily infects the immunocompromised. Whereas the genome of one isolate, C. tropicalis MYA-3404, was originally sequenced in 2009, there have been no large-scale, multi-isolate studies of the genetic and phenotypic diversity of this species. Here, we used whole genome sequencing and phenotyping to characterize 77 isolates of C. tropicalis from clinical and environmental sources from a variety of locations. We show that most C. tropicalis isolates are diploids with approximately 2-6 heterozygous variants per kilobase. The genomes are relatively stable, with few aneuploidies. However, we identified one highly homozygous isolate and six isolates of C. tropicalis with much higher heterozygosity levels ranging from 36-49 heterozygous variants per kilobase. Our analyses show that the heterozygous isolates represent two different hybrid lineages, where the hybrids share one parent (A) with most other C. tropicalis isolates, but the second parent (B or C) differs by at least 4% at the genome level. Four of the sequenced isolates descend from an AB hybridization, and two from an AC hybridization. The hybrids are MTLa/α heterozygotes. Hybridization, or mating, between different parents is therefore common in the evolutionary history of C. tropicalis. The new hybrids were predominantly found in environmental niches, including from soil. Hybridization is therefore unlikely to be associated with virulence. In addition, we used genotype-phenotype correlation and CRISPR-Cas9 editing to identify a genome variant that results in the inability of one isolate to utilize certain branched-chain amino acids as a sole nitrogen source.
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Affiliation(s)
- Caoimhe E. O’Brien
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - João Oliveira-Pacheco
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Eoin Ó Cinnéide
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Max A. B. Haase
- Laboratory of Genetics, Center for Genomic Science Innovation, Wisconsin Energy Institute, DOE Great Lakes Bioenergy Research Center, J.F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chris Todd Hittinger
- Laboratory of Genetics, Center for Genomic Science Innovation, Wisconsin Energy Institute, DOE Great Lakes Bioenergy Research Center, J.F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Thomas R. Rogers
- Department of Clinical Microbiology, Trinity College Dublin, Dublin, Ireland; Department of Microbiology, St James’s Hospital, Dublin, Ireland
| | - Oscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km2, Majadahonda, Madrid, Spain
| | - Ursula Bond
- Department of Microbiology, School of Genetics and Microbiology, Trinity College Dublin, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
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6
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Zhao S, Ge W, Watanabe A, Fortwendel JR, Gibbons JG. Genome-Wide Association for Itraconazole Sensitivity in Non-resistant Clinical Isolates of Aspergillus fumigatus. FRONTIERS IN FUNGAL BIOLOGY 2021; 1:617338. [PMID: 37743877 PMCID: PMC10512406 DOI: 10.3389/ffunb.2020.617338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/15/2020] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is a potentially lethal opportunistic pathogen that infects over ~200,000 people and causes ~100,000 deaths per year globally. Treating A. fumigatus infections is particularly challenging because of the recent emergence of azole-resistance. The majority of studies focusing on the molecular mechanisms underlying azole resistance have examined azole-resistant isolates. However, isolates that are susceptible to azoles also display variation in their sensitivity, presenting a unique opportunity to identify genes contributing to azole sensitivity. Here, we used genome-wide association (GWA) analysis to identify loci involved in azole sensitivity by analyzing the association between 68,853 SNPs and itraconazole (ITCZ) minimum inhibitory concentration (MIC) in 76 clinical isolates of A. fumigatus from Japan. Population structure analysis suggests the presence of four distinct populations, with ITCZ MICs distributed relatively evenly across populations. We independently conducted GWA when treating ITCZ MIC as a quantitative trait and a binary trait, and identified two SNPs with strong associations in both analyses. These SNPs fell within the coding regions of Afu2g02220 and Afu2g02140. We functionally validated Afu2g02220 by knocking it out using a CRISPR/Cas9 approach, because orthologs of this gene are involved in sterol modification and ITCZ targets the ergosterol biosynthesis pathway. Knockout strains displayed no difference in growth compared to the parent strain in minimal media, yet a minor but consistent inhibition of growth in the presence of 0.15 μg/ml ITCZ. Our results suggest that GWA paired with efficient gene deletion is a powerful and unbiased strategy for identifying the genetic basis of complex traits in A. fumigatus.
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Affiliation(s)
- Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Wenbo Ge
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Akira Watanabe
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
| | - John G. Gibbons
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
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7
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Raghavan V, Aquadro CF, Alani E. Baker's Yeast Clinical Isolates Provide a Model for How Pathogenic Yeasts Adapt to Stress. Trends Genet 2019; 35:804-817. [PMID: 31526615 PMCID: PMC6825890 DOI: 10.1016/j.tig.2019.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/07/2019] [Accepted: 08/19/2019] [Indexed: 12/26/2022]
Abstract
Global outbreaks of drug-resistant fungi such as Candida auris are thought to be due at least in part to excessive use of antifungal drugs. Baker's yeast Saccharomyces cerevisiae has gained importance as an emerging opportunistic fungal pathogen that can cause infections in immunocompromised patients. Analyses of over 1000 S. cerevisiae isolates are providing rich resources to better understand how fungi can grow in human environments. A large percentage of clinical S. cerevisiae isolates are heterozygous across many nucleotide sites, and a significant proportion are of mixed ancestry and/or are aneuploid or polyploid. Such features potentially facilitate adaptation to new environments. These observations provide strong impetus for expanding genomic and molecular studies on clinical and wild isolates to understand the prevalence of genetic diversity and instability-generating mechanisms, and how they are selected for and maintained. Such work can also lead to the identification of new targets for antifungal drugs.
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Affiliation(s)
- Vandana Raghavan
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Charles F Aquadro
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Eric Alani
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
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8
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Yadav A, Sinha H. Gene-gene and gene-environment interactions in complex traits in yeast. Yeast 2018; 35:403-416. [PMID: 29322552 DOI: 10.1002/yea.3304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/11/2017] [Accepted: 12/23/2017] [Indexed: 01/05/2023] Open
Abstract
One of the fundamental questions in biology is how the genotype regulates the phenotype. An increasing number of studies indicate that, in most cases, the effect of a genetic locus on the phenotype is context-dependent, i.e. it is influenced by the genetic background and the environment in which the phenotype is measured. Still, the majority of the studies, in both model organisms and humans, that map the genetic regulation of phenotypic variation in complex traits primarily identify additive loci with independent effects. This does not reflect an absence of the contribution of genetic interactions to phenotypic variation, but instead is a consequence of the technical limitations in mapping gene-gene interactions (GGI) and gene-environment interactions (GEI). Yeast, with its detailed molecular understanding, diverse population genomics and ease of genetic manipulation, is a unique and powerful resource to study the contributions of GGI and GEI in the regulation of phenotypic variation. Here we review studies in yeast that have identified GGI and GEI that regulate phenotypic variation, and discuss the contribution of these findings in explaining missing heritability of complex traits, and how observations from these GGI and GEI studies enhance our understanding of the mechanisms underlying genetic robustness and adaptability that shape the architecture of the genotype-phenotype map.
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Affiliation(s)
- Anupama Yadav
- Center for Cancer Systems Biology, and Cancer Biology, Dana Farber Cancer Institute, Boston, MA, 02215, USA.,Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Himanshu Sinha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India.,Initiative for Biological Systems Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.,Robert Bosch Centre for Data Sciences and Artificial Intelligence, Indian Institute of Technology Madras, Chennai, 600036, India
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9
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Teixeira MM, Barker BM. Use of Population Genetics to Assess the Ecology, Evolution, and Population Structure of Coccidioides. Emerg Infect Dis 2018; 22:1022-30. [PMID: 27191589 PMCID: PMC4880095 DOI: 10.3201/eid2206.151565] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although Coccidioides genotypes are highly genetically variable,
they cluster into discrete populations, which has implications for human
infections. During the past 20 years, a general picture of the genetic diversity and population
structure of Coccidioides, the causal agent of coccidioidomycosis
(Valley fever), has emerged. The genus consists of 2 genetically diverse species,
C. immitis and C. posadasii, each of which
contains 1 or more distinct populations with limited gene flow. Genotypic data
indicate that C. immitis is divided into 2 subpopulations (central
and southern California populations) and C. posadasii is divided
into 3 subpopulations (Arizona, Mexico, and Texas/South America populations).
However, admixture within and among these populations and the current paucity of
environmental isolates limit our understanding of the population genetics of
Coccidioides. We assessed population structure of
Coccidioides in Arizona by analyzing 495 clinical and
environmental isolates. Our findings confirm the population structure as previously
described and indicate a finer scale population structure in Arizona. Environmental
isolates appear to have higher genetic diversity than isolates from human
patients.
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10
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Genome-Wide Screen for Saccharomyces cerevisiae Genes Contributing to Opportunistic Pathogenicity in an Invertebrate Model Host. G3-GENES GENOMES GENETICS 2018; 8:63-78. [PMID: 29122853 PMCID: PMC5765367 DOI: 10.1534/g3.117.300245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Environmental opportunistic pathogens can exploit vulnerable hosts through expression of traits selected for in their natural environments. Pathogenicity is itself a complicated trait underpinned by multiple complex traits, such as thermotolerance, morphology, and stress response. The baker's yeast, Saccharomyces cerevisiae, is a species with broad environmental tolerance that has been increasingly reported as an opportunistic pathogen of humans. Here we leveraged the genetic resources available in yeast and a model insect species, the greater waxmoth Galleria mellonella, to provide a genome-wide analysis of pathogenicity factors. Using serial passaging experiments of genetically marked wild-type strains, a hybrid strain was identified as the most fit genotype across all replicates. To dissect the genetic basis for pathogenicity in the hybrid isolate, bulk segregant analysis was performed which revealed eight quantitative trait loci significantly differing between the two bulks with alleles from both parents contributing to pathogenicity. A second passaging experiment with a library of deletion mutants for most yeast genes identified a large number of mutations whose relative fitness differed in vivovs.in vitro, including mutations in genes controlling cell wall integrity, mitochondrial function, and tyrosine metabolism. Yeast is presumably subjected to a massive assault by the innate insect immune system that leads to melanization of the host and to a large bottleneck in yeast population size. Our data support that resistance to the innate immune response of the insect is key to survival in the host and identifies shared genetic mechanisms between S. cerevisiae and other opportunistic fungal pathogens.
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11
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High-resolution mapping of cis-regulatory variation in budding yeast. Proc Natl Acad Sci U S A 2017; 114:E10736-E10744. [PMID: 29183975 DOI: 10.1073/pnas.1717421114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Genetic variants affecting gene-expression levels are a major source of phenotypic variation. The approximate locations of these variants can be mapped as expression quantitative trait loci (eQTLs); however, a major limitation of eQTLs is their low resolution, which precludes investigation of the causal variants and their molecular mechanisms. Here we report RNA-seq and full genome sequences for 85 diverse isolates of the yeast Saccharomyces cerevisiae-including wild, domesticated, and human clinical strains-which allowed us to perform eQTL mapping with 50-fold higher resolution than previously possible. In addition to variants in promoters, we uncovered an important role for variants in 3'UTRs, especially those affecting binding of the PUF family of RNA-binding proteins. The eQTLs are predominantly under negative selection, particularly those affecting essential genes and conserved genes. However, applying the sign test for lineage-specific selection revealed the polygenic up-regulation of dozens of biofilm suppressor genes in strains isolated from human patients, consistent with the key role of biofilms in fungal pathogenicity. In addition, a single variant in the promoter of a biofilm suppressor, NIT3, showed the strongest genome-wide association with clinical origin. Altogether, our results demonstrate the power of high-resolution eQTL mapping in understanding the molecular mechanisms of regulatory variation, as well as the natural selection acting on this variation that drives adaptation to environments, ranging from laboratories to vineyards to the human body.
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12
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He X, Jin Y, Ye M, Chen N, Zhu J, Wang J, Jiang L, Wu R. Bacterial Genetic Architecture of Ecological Interactions in Co-culture by GWAS-Taking Escherichia coli and Staphylococcus aureus as an Example. Front Microbiol 2017; 8:2332. [PMID: 29230205 PMCID: PMC5712204 DOI: 10.3389/fmicb.2017.02332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/13/2017] [Indexed: 11/22/2022] Open
Abstract
How a species responds to such a biotic environment in the community, ultimately leading to its evolution, has been a topic of intense interest to ecological evolutionary biologists. Until recently, limited knowledge was available regarding the genotypic changes that underlie phenotypic changes. Our study implemented GWAS (Genome-Wide Association Studies) to illustrate the genetic architecture of ecological interactions that take place in microbial populations. By choosing 45 such interspecific pairs of Escherichia coli and Staphylococcus aureus strains that were all genotyped throughout the entire genome, we employed Q-ROADTRIPS to analyze the association between single SNPs and microbial abundance measured at each time point for bacterial populations reared in monoculture and co-culture, respectively. We identified a large number of SNPs and indels across the genomes (35.69 G clean data of E. coli and 50.41 G of S. aureus). We reported 66 and 111 SNPs that were associated with interaction in E. coli and S. aureus, respectively. 23 out of 66 polymorphic changes resulted in amino acid alterations.12 significant genes, such as murE, treA, argS, and relA, which were also identified in previous evolutionary studies. In S. aureus, 111 SNPs detected in coding sequences could be divided into 35 non-synonymous and 76 synonymous SNPs. Our study illustrated the potential of genome-wide association methods for studying rapidly evolving traits in bacteria. Genetic association study methods will facilitate the identification of genetic elements likely to cause phenotypes of interest and provide targets for further laboratory investigation.
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Affiliation(s)
- Xiaoqing He
- Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Yi Jin
- Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Meixia Ye
- Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Nan Chen
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Jing Zhu
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Jingqi Wang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Libo Jiang
- Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Rongling Wu
- Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.,Center for Statistical Genetics, Pennsylvania State University, Hershey, PA, United States
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13
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Pfliegler WP, Boros E, Pázmándi K, Jakab Á, Zsuga I, Kovács R, Urbán E, Antunovics Z, Bácsi A, Sipiczki M, Majoros L, Pócsi I. Commercial strain-derived clinicalSaccharomyces cerevisiaecan evolve new phenotypes without higher pathogenicity. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201601099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 06/08/2017] [Accepted: 06/28/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Walter P. Pfliegler
- Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
- Postdoctoral Fellowship Programme of the Hungarian Academy of Sciences (MTA); Budapest Hungary
| | - Enikő Boros
- Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Kitti Pázmándi
- Department of Immunology; University of Debrecen; Debrecen Hungary
| | - Ágnes Jakab
- Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Imre Zsuga
- Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Renátó Kovács
- Department of Medical Microbiology; University of Debrecen; Debrecen Hungary
- Faculty of Pharmacy; University of Debrecen; Debrecen Hungary
| | - Edit Urbán
- Institute of Clinical Microbiology; University of Szeged; Szeged Hungary
| | - Zsuzsa Antunovics
- Department of Genetics and Applied Microbiology; University of Debrecen; Debrecen Hungary
| | - Attila Bácsi
- Department of Immunology; University of Debrecen; Debrecen Hungary
| | - Matthias Sipiczki
- Department of Genetics and Applied Microbiology; University of Debrecen; Debrecen Hungary
| | - László Majoros
- Department of Medical Microbiology; University of Debrecen; Debrecen Hungary
| | - István Pócsi
- Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
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14
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Liti G, Warringer J, Blomberg A. Budding Yeast Strains and Genotype-Phenotype Mapping. Cold Spring Harb Protoc 2017; 2017:pdb.top077735. [PMID: 28765302 DOI: 10.1101/pdb.top077735] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A small number of well-studied laboratory strains of Saccharomyces cerevisiae, mostly derived from S288C, are used in yeast research. Although powerful, studies for understanding S288C do not always capture the phenotypic essence or the genetic complexity of S. cerevisiae biology. This is particularly problematic for multilocus phenotypes identified in laboratory strains because these loci have never been jointly exposed to natural selection and the corresponding phenotypes do not represent optimization for any particular purpose or environment. Isolation and sequencing of new natural yeast strains also reveal that the total sequence diversity of the S. cerevisiae global population is poorly sampled in common laboratory strains. Here we discuss methodologies required for using the natural genetic variation in yeast to complete a genotype-phenotype map.
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Affiliation(s)
- Gianni Liti
- IRCAN, CNRS UMR 6267, INSERM U998, University of Nice, 06107 Nice, France
| | - Jonas Warringer
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden.,Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences (UMB), 1432 Ås, Norway
| | - Anders Blomberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden;
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15
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Brysch-Herzberg M, Seidel M. Distribution patterns of Saccharomyces species in cultural landscapes of Germany. FEMS Yeast Res 2017; 17:3829890. [DOI: 10.1093/femsyr/fox033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/16/2017] [Indexed: 12/30/2022] Open
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Genome Sequences of Cyberlindnera fabianii 65, Pichia kudriavzevii 129, and Saccharomyces cerevisiae 131 Isolated from Fermented Masau Fruits in Zimbabwe. GENOME ANNOUNCEMENTS 2017; 5:5/14/e00064-17. [PMID: 28385833 PMCID: PMC5383881 DOI: 10.1128/genomea.00064-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cyberlindnera fabianii 65, Pichia kudriavzevii 129, and Saccharomyces cerevisiae 131 have been isolated from the microbiota of fermented masau fruits. C. fabianii and P. kudriavzevii especially harbor promising features for biotechnology and food applications. Here, we present the draft annotated genome sequences of these isolates.
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17
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Zhong Z, Marcel TC, Hartmann FE, Ma X, Plissonneau C, Zala M, Ducasse A, Confais J, Compain J, Lapalu N, Amselem J, McDonald BA, Croll D, Palma-Guerrero J. A small secreted protein in Zymoseptoria tritici is responsible for avirulence on wheat cultivars carrying the Stb6 resistance gene. THE NEW PHYTOLOGIST 2017; 214:619-631. [PMID: 28164301 DOI: 10.1111/nph.14434] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/09/2016] [Indexed: 05/06/2023]
Abstract
Zymoseptoria tritici is the causal agent of Septoria tritici blotch, a major pathogen of wheat globally and the most damaging pathogen of wheat in Europe. A gene-for-gene (GFG) interaction between Z. tritici and wheat cultivars carrying the Stb6 resistance gene has been postulated for many years, but the genes have not been identified. We identified AvrStb6 by combining quantitative trait locus mapping in a cross between two Swiss strains with a genome-wide association study using a natural population of c. 100 strains from France. We functionally validated AvrStb6 using ectopic transformations. AvrStb6 encodes a small, cysteine-rich, secreted protein that produces an avirulence phenotype on wheat cultivars carrying the Stb6 resistance gene. We found 16 nonsynonymous single nucleotide polymorphisms among the tested strains, indicating that AvrStb6 is evolving very rapidly. AvrStb6 is located in a highly polymorphic subtelomeric region and is surrounded by transposable elements, which may facilitate its rapid evolution to overcome Stb6 resistance. AvrStb6 is the first avirulence gene to be functionally validated in Z. tritici, contributing to our understanding of avirulence in apoplastic pathogens and the mechanisms underlying GFG interactions between Z. tritici and wheat.
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Affiliation(s)
- Ziming Zhong
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Thierry C Marcel
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
| | - Fanny E Hartmann
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Xin Ma
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Clémence Plissonneau
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
| | - Marcello Zala
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Aurélie Ducasse
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
| | - Johann Confais
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
| | - Jérôme Compain
- UR URGI, INRA, Université Paris-Saclay, 78026, Versailles, France
| | - Nicolas Lapalu
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
- UR URGI, INRA, Université Paris-Saclay, 78026, Versailles, France
| | - Joëlle Amselem
- UR URGI, INRA, Université Paris-Saclay, 78026, Versailles, France
| | - Bruce A McDonald
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Daniel Croll
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
- Laboratory of Evolutionary Genetics, University of Neuchâtel Institute of Biology Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland
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Plissonneau C, Benevenuto J, Mohd-Assaad N, Fouché S, Hartmann FE, Croll D. Using Population and Comparative Genomics to Understand the Genetic Basis of Effector-Driven Fungal Pathogen Evolution. FRONTIERS IN PLANT SCIENCE 2017; 8:119. [PMID: 28217138 PMCID: PMC5289978 DOI: 10.3389/fpls.2017.00119] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/20/2017] [Indexed: 05/20/2023]
Abstract
Epidemics caused by fungal plant pathogens pose a major threat to agro-ecosystems and impact global food security. High-throughput sequencing enabled major advances in understanding how pathogens cause disease on crops. Hundreds of fungal genomes are now available and analyzing these genomes highlighted the key role of effector genes in disease. Effectors are small secreted proteins that enhance infection by manipulating host metabolism. Fungal genomes carry 100s of putative effector genes, but the lack of homology among effector genes, even for closely related species, challenges evolutionary and functional analyses. Furthermore, effector genes are often found in rapidly evolving chromosome compartments which are difficult to assemble. We review how population and comparative genomics toolsets can be combined to address these challenges. We highlight studies that associated genome-scale polymorphisms with pathogen lifestyles and adaptation to different environments. We show how genome-wide association studies can be used to identify effectors and other pathogenicity-related genes underlying rapid adaptation. We also discuss how the compartmentalization of fungal genomes into core and accessory regions shapes the evolution of effector genes. We argue that an understanding of genome evolution provides important insight into the trajectory of host-pathogen co-evolution.
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Affiliation(s)
- Clémence Plissonneau
- Plant Pathology, Institute of Integrative Biology, ETH ZurichZurich, Switzerland
- UMR, BIOGER, INRA, AgroParisTech, Université Paris-SaclayThiverval-Grignon, France
| | - Juliana Benevenuto
- College of Agriculture “Luiz de Queiroz”, University of São PauloSão Paulo, Brazil
| | - Norfarhan Mohd-Assaad
- Plant Pathology, Institute of Integrative Biology, ETH ZurichZurich, Switzerland
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan MalaysiaSelangor, Malaysia
| | - Simone Fouché
- Plant Pathology, Institute of Integrative Biology, ETH ZurichZurich, Switzerland
| | - Fanny E. Hartmann
- Plant Pathology, Institute of Integrative Biology, ETH ZurichZurich, Switzerland
| | - Daniel Croll
- Plant Pathology, Institute of Integrative Biology, ETH ZurichZurich, Switzerland
- Laboratory of Evolutionary Genetics, Institute of Biology, University of NeuchatelNeuchatel, Switzerland
- *Correspondence: Daniel Croll,
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Gao Y, Liu Z, Faris JD, Richards J, Brueggeman RS, Li X, Oliver RP, McDonald BA, Friesen TL. Validation of Genome-Wide Association Studies as a Tool to Identify Virulence Factors in Parastagonospora nodorum. PHYTOPATHOLOGY 2016; 106:1177-1185. [PMID: 27442533 DOI: 10.1094/phyto-02-16-0113-fi] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Parastagonospora nodorum is a necrotrophic fungal pathogen causing Septoria nodorum blotch on wheat. We have identified nine necrotrophic effector-host dominant sensitivity gene interactions, and we have cloned three of the necrotrophic effector genes, including SnToxA, SnTox1, and SnTox3. Because sexual populations of P. nodorum are difficult to develop under lab conditions, genome-wide association study (GWAS) is the best population genomic approach to identify genomic regions associated with traits using natural populations. In this article, we used a global collection of 191 P. nodorum isolates from which we identified 2,983 single-nucleotide polymorphism (SNP) markers and gene markers for SnToxA and SnTox3 to evaluate the power of GWAS on two popular wheat breeding lines that were sensitive to SnToxA and SnTox3. Strong marker trait associations (MTA) with P. nodorum virulence that mapped to SnTox3 and SnToxA were first identified using the marker set described above. A novel locus in the P. nodorum genome associated with virulence was also identified as a result of this analysis. To evaluate whether a sufficient level of marker saturation was available, we designed a set of primers every 1 kb in the genomic regions containing SnToxA and SnTox3. Polymerase chain reaction amplification was performed across the 191 isolates and the presence/absence polymorphism was scored and used as the genotype. The marker proximity necessary to identify MTA flanking SnToxA and SnTox3 ranged from 4 to 5 and 1 to 7 kb, respectively. Similar analysis was performed on the novel locus. Using a 45% missing data threshold, two more SNP were identified spanning a 4.6-kb genomic region at the novel locus. These results showed that the rate of linkage disequilibrium (LD) decay in P. nodorum and, likely, other fungi is high compared with plants and animals. The fast LD decay in P. nodorum is an advantage only if sufficient marker density is attained. Based on our results with the SnToxA and SnTox3 regions, markers are needed every 9 or 8 kb, respectively, or in every gene, to guarantee that genes associated with a quantitative trait such as virulence are not missed.
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Affiliation(s)
- Yuanyuan Gao
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Zhaohui Liu
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Justin D Faris
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Jonathan Richards
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Robert S Brueggeman
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Xuehui Li
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Richard P Oliver
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Bruce A McDonald
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
| | - Timothy L Friesen
- First, second, fourth, fifth, and ninth authors: Department of Plant Pathology, North Dakota State University, Fargo 58108; third and ninth authors: United States Department of Agriculture-Agricultural Research Service, Northern Crop Science Laboratory, Cereal Crops Research Unit, Fargo, ND, 58102; sixth author: Department of Plant Science, North Dakota State University, Fargo; seventh author: Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Perth, WA 6102, Australia; and eighth author: Institute of Integrative Biology, Plant Pathology Group, Swiss Federal Institute of Technology, ETH Zentrum, LFW, CH-8092 Zürich, Switzerland
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Whole Genome Analysis of 132 Clinical Saccharomyces cerevisiae Strains Reveals Extensive Ploidy Variation. G3-GENES GENOMES GENETICS 2016; 6:2421-34. [PMID: 27317778 PMCID: PMC4978896 DOI: 10.1534/g3.116.029397] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Budding yeast has undergone several independent transitions from commercial to clinical lifestyles. The frequency of such transitions suggests that clinical yeast strains are derived from environmentally available yeast populations, including commercial sources. However, despite their important role in adaptive evolution, the prevalence of polyploidy and aneuploidy has not been extensively analyzed in clinical strains. In this study, we have looked for patterns governing the transition to clinical invasion in the largest screen of clinical yeast isolates to date. In particular, we have focused on the hypothesis that ploidy changes have influenced adaptive processes. We sequenced 144 yeast strains, 132 of which are clinical isolates. We found pervasive large-scale genomic variation in both overall ploidy (34% of strains identified as 3n/4n) and individual chromosomal copy numbers (36% of strains identified as aneuploid). We also found evidence for the highly dynamic nature of yeast genomes, with 35 strains showing partial chromosomal copy number changes and eight strains showing multiple independent chromosomal events. Intriguingly, a lineage identified to be baker's/commercial derived with a unique damaging mutation in NDC80 was particularly prone to polyploidy, with 83% of its members being triploid or tetraploid. Polyploidy was in turn associated with a >2× increase in aneuploidy rates as compared to other lineages. This dataset provides a rich source of information on the genomics of clinical yeast strains and highlights the potential importance of large-scale genomic copy variation in yeast adaptation.
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21
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Identification of Diverse Mycoviruses through Metatranscriptomics Characterization of the Viromes of Five Major Fungal Plant Pathogens. J Virol 2016; 90:6846-6863. [PMID: 27194764 DOI: 10.1128/jvi.00357-16] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/11/2016] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Mycoviruses can have a marked effect on natural fungal communities and influence plant health and productivity. However, a comprehensive picture of mycoviral diversity is still lacking. To characterize the viromes of five widely dispersed plant-pathogenic fungi, Colletotrichum truncatum, Macrophomina phaseolina, Diaporthe longicolla, Rhizoctonia solani, and Sclerotinia sclerotiorum, a high-throughput sequencing-based metatranscriptomic approach was used to detect viral sequences. Total RNA and double-stranded RNA (dsRNA) from mycelia and RNA from samples enriched for virus particles were sequenced. Sequence data were assembled de novo, and contigs with predicted amino acid sequence similarities to viruses in the nonredundant protein database were selected. The analysis identified 72 partial or complete genome segments representing 66 previously undescribed mycoviruses. Using primers specific for each viral contig, at least one fungal isolate was identified that contained each virus. The novel mycoviruses showed affinity with 15 distinct lineages: Barnaviridae, Benyviridae, Chrysoviridae, Endornaviridae, Fusariviridae, Hypoviridae, Mononegavirales, Narnaviridae, Ophioviridae, Ourmiavirus, Partitiviridae, Tombusviridae, Totiviridae, Tymoviridae, and Virgaviridae More than half of the viral sequences were predicted to be members of the Mitovirus genus in the family Narnaviridae, which replicate within mitochondria. Five viral sequences showed strong affinity with three families (Benyviridae, Ophioviridae, and Virgaviridae) that previously contained no mycovirus species. The genomic information provides insight into the diversity and taxonomy of mycoviruses and coevolution of mycoviruses and their fungal hosts. IMPORTANCE Plant-pathogenic fungi reduce crop yields, which affects food security worldwide. Plant host resistance is considered a sustainable disease management option but may often be incomplete or lacking for some crops to certain fungal pathogens or strains. In addition, the rising issues of fungicide resistance demand alternative strategies to reduce the negative impacts of fungal pathogens. Those fungus-infecting viruses (mycoviruses) that attenuate fungal virulence may be welcome additions for mitigation of plant diseases. By high-throughput sequencing of the RNAs from 275 isolates of five fungal plant pathogens, 66 previously undescribed mycoviruses were identified. In addition to identifying new potential biological control agents, these results expand the grand view of the diversity of mycoviruses and provide possible insights into the importance of intracellular and extracellular transmission in fungus-virus coevolution.
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Talas F, Kalih R, Miedaner T, McDonald BA. Genome-Wide Association Study Identifies Novel Candidate Genes for Aggressiveness, Deoxynivalenol Production, and Azole Sensitivity in Natural Field Populations of Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:417-30. [PMID: 26959837 DOI: 10.1094/mpmi-09-15-0218-r] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Genome-wide association studies can identify novel genomic regions and genes that affect quantitative traits. Fusarium head blight is a destructive disease caused by Fusarium graminearum that exhibits several quantitative traits, including aggressiveness, mycotoxin production, and fungicide resistance. Restriction site-associated DNA sequencing was performed for 220 isolates of F. graminearum. A total of 119 isolates were phenotyped for aggressiveness and deoxynivalenol (DON) production under natural field conditions across four environments. The effective concentration of propiconazole that inhibits isolate growth in vitro by 50% was calculated for 220 strains. Approximately 29,000 single nucleotide polymorphism markers were associated to each trait, resulting in 50, 29, and 74 quantitative trait nucleotides (QTNs) that were significantly associated to aggressiveness, DON production, and propiconazole sensitivity, respectively. Approximately 41% of these QTNs caused nonsynonymous substitutions in predicted exons, while the remainder were synonymous substitutions or located in intergenic regions. Three QTNs associated with propiconazole sensitivity were significant after Bonferroni correction. These QTNs were located in genes not previously associated with azole sensitivity. The majority of the detected QTNs were located in genes with predicted regulatory functions, suggesting that nucleotide variation in regulatory genes plays a major role in the corresponding quantitative trait variation.
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23
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Peter J, Schacherer J. Population genomics of yeasts: towards a comprehensive view across a broad evolutionary scale. Yeast 2016; 33:73-81. [PMID: 26592376 DOI: 10.1002/yea.3142] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 11/08/2022] Open
Abstract
With the advent of high-throughput technologies for sequencing, the complete description of the genetic variation that occurs in populations, also known as population genomics, is foreseeable but far from being reached. Explaining the forces that govern patterns of genetic variation is essential to elucidate the evolutionary history of species. Genetic variation results from a wide assortment of evolutionary forces, among which mutation, selection, recombination and drift play major roles in shaping genomes. In addition, exploring the genetic variation within a population also corresponds to the first step towards dissecting the genotype-phenotype relationship. In this context, yeast species are of particular interest because they represent a unique resource for studying the evolution of intraspecific genetic diversity in a phylum spanning a broad evolutionary scale. Here, we briefly review recent progress in yeast population genomics and provide some perspective on this rapidly evolving field. In fact, we truly believe that it is of interest to supplement comparative and early population genomic studies with the deep sequencing of more extensive sets of individuals from the same species. In parallel, it would be more than valuable to uncover the intraspecific variation of a large number of unexplored species, including those that are closely and more distantly related. Altogether, these data would enable substantially more powerful genomic scans for functional dissection.
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Affiliation(s)
- Jackson Peter
- Department of Genetics, Genomics and Microbiology, University of Strasbourg/CNRS, UMR7156, Strasbourg, France
| | - Joseph Schacherer
- Department of Genetics, Genomics and Microbiology, University of Strasbourg/CNRS, UMR7156, Strasbourg, France
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24
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Marques WL, Raghavendran V, Stambuk BU, Gombert AK. Sucrose and Saccharomyces cerevisiae: a relationship most sweet. FEMS Yeast Res 2015; 16:fov107. [PMID: 26658003 DOI: 10.1093/femsyr/fov107] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2015] [Indexed: 12/16/2022] Open
Abstract
Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering.
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Affiliation(s)
- Wesley Leoricy Marques
- Department of Chemical Engineering, University of São Paulo, São Paulo-SP, 05424-970, Brazil School of Food Engineering, University of Campinas, Campinas-SP, 13083-862, Brazil
| | | | - Boris Ugarte Stambuk
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis-SC, 88040-900, Brazil
| | - Andreas Karoly Gombert
- Department of Chemical Engineering, University of São Paulo, São Paulo-SP, 05424-970, Brazil School of Food Engineering, University of Campinas, Campinas-SP, 13083-862, Brazil
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Hou J, Schacherer J. On the Mapping of Epistatic Genetic Interactions in Natural Isolates: Combining Classical Genetics and Genomics. Methods Mol Biol 2015; 1361:345-60. [PMID: 26483031 DOI: 10.1007/978-1-4939-3079-1_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Genetic variation within species is the substrate of evolution. Epistasis, which designates the non-additive interaction between loci affecting a specific phenotype, could be one of the possible outcomes of genetic diversity. Dissecting the basis of such interactions is of current interest in different fields of biology, from exploring the gene regulatory network, to complex disease genetics, to the onset of reproductive isolation and speciation. We present here a general workflow to identify epistatic interactions between independently evolving loci in natural populations of the yeast Saccharomyces cerevisiae. The idea is to exploit the genetic diversity present in the species by evaluating a large number of crosses and analyzing the phenotypic distribution in the offspring. For a cross of interest, both parental strains would have a similar phenotypic value, whereas the resulting offspring would have a bimodal distribution of the phenotype, possibly indicating the presence of epistasis. Classical segregation analysis of the tetrads uncovers the penetrance and complexity of the interaction. In addition, this segregation could serve as the guidelines for choosing appropriate mapping strategies to narrow down the genomic regions involved. Depending on the segregation patterns observed, we propose different mapping strategies based on bulk segregant analysis or consecutive backcrosses followed by high-throughput genome sequencing. Our method is generally applicable to all systems with a haplodiplobiontic life cycle and allows high resolution mapping of interacting loci that govern various DNA polymorphisms from single nucleotide mutations to large-scale structural variations.
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Affiliation(s)
- Jing Hou
- Department of Genetics, Genomics and Microbiology, CNRS, UMR7156, Université de Strasbourg, Strasbourg, France
| | - Joseph Schacherer
- Department of Genetics, Genomics and Microbiology, CNRS, UMR7156, Université de Strasbourg, Strasbourg, France.
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Hsu PH, Chiang PC, Liu CH, Chang YW. Characterization of Cell Wall Proteins in Saccharomyces cerevisiae Clinical Isolates Elucidates Hsp150p in Virulence. PLoS One 2015; 10:e0135174. [PMID: 26270963 PMCID: PMC4535956 DOI: 10.1371/journal.pone.0135174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/17/2015] [Indexed: 11/25/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae has recently been described as an emerging opportunistic fungal pathogen. Fungal cell wall mannoproteins have been demonstrated to be involved in adhesion to inert surfaces and might be engaged in virulence. In this study, we observed four clinical isolates of S. cerevisiae with relatively hydrophobic cell surfaces. Yeast cell wall subproteome was evaluated quantitatively by liquid chromatography/tandem mass spectrometry. We identified totally 25 cell wall proteins (CWPs) from log-phase cells, within which 15 CWPs were quantified. The abundance of Scw10p, Pst1p, and Hsp150p/Pir2p were at least 2 folds higher in the clinical isolates than in S288c lab strain. Hsp150p is one of the members in Pir family conserved in pathogenic fungi Candida glabrata and Candida albicans. Overexpression of Hsp150p in lab strain increased cell wall integrity and potentially enhanced the virulence of yeast. Altogether, these results demonstrated that quantitative cell wall subproteome was analyzed in clinical isolates of S. cerevisiae, and several CWPs, especially Hsp150p, were found to be expressed at higher levels which presumably contribute to strain virulence and fungal pathogenicity.
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Affiliation(s)
- Pang-Hung Hsu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
- * E-mail: (YC); (PH)
| | - Pei-Chi Chiang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Chia-Hsun Liu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
| | - Ya-Wen Chang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail: (YC); (PH)
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Anoop V, Rotaru S, Shwed PS, Tayabali AF, Arvanitakis G. Review of current methods for characterizing virulence and pathogenicity potential of industrial Saccharomyces cerevisiae strains towards humans. FEMS Yeast Res 2015. [PMID: 26195617 DOI: 10.1093/femsyr/fov057] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Most industrial Saccharomyces cerevisiae strains used in food or biotechnology processes are benign. However, reports of S. cerevisiae infections have emerged and novel strains continue to be developed. In order to develop recommendations for the human health risk assessment of S. cerevisiae strains, we conducted a literature review of current methods used to characterize their pathogenic potential and evaluated their relevance towards risk assessment. These studies revealed that expression of virulence traits in S. cerevisiae is complex and depends on many factors. Given the opportunistic nature of this organism, an approach using multiple lines of evidence is likely necessary for the reasonable prediction of the pathogenic potential of a particular strain. Risk assessment of S. cerevisiae strains would benefit from more research towards the comparison of virulent and non-virulent strains in order to better understand those genotypic and phenotypic traits most likely to be associated with pathogenicity.
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Affiliation(s)
- Valar Anoop
- New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 99 Metcalfe Street, Floor-11, Ottawa, ON K1A 0K9, Canada
| | - Sever Rotaru
- New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 99 Metcalfe Street, Floor-11, Ottawa, ON K1A 0K9, Canada
| | - Philip S Shwed
- Environmental Health Science Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON K1A0K9, Canada
| | - Azam F Tayabali
- Environmental Health Science Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON K1A0K9, Canada
| | - George Arvanitakis
- New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 99 Metcalfe Street, Floor-11, Ottawa, ON K1A 0K9, Canada
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Strope PK, Skelly DA, Kozmin SG, Mahadevan G, Stone EA, Magwene PM, Dietrich FS, McCusker JH. The 100-genomes strains, an S. cerevisiae resource that illuminates its natural phenotypic and genotypic variation and emergence as an opportunistic pathogen. Genome Res 2015; 25:762-74. [PMID: 25840857 PMCID: PMC4417123 DOI: 10.1101/gr.185538.114] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/18/2015] [Indexed: 12/18/2022]
Abstract
Saccharomyces cerevisiae, a well-established model for species as diverse as humans and pathogenic fungi, is more recently a model for population and quantitative genetics. S. cerevisiae is found in multiple environments—one of which is the human body—as an opportunistic pathogen. To aid in the understanding of the S. cerevisiae population and quantitative genetics, as well as its emergence as an opportunistic pathogen, we sequenced, de novo assembled, and extensively manually edited and annotated the genomes of 93 S. cerevisiae strains from multiple geographic and environmental origins, including many clinical origin strains. These 93 S. cerevisiae strains, the genomes of which are near-reference quality, together with seven previously sequenced strains, constitute a novel genetic resource, the “100-genomes” strains. Our sequencing coverage, high-quality assemblies, and annotation provide unprecedented opportunities for detailed interrogation of complex genomic loci, examples of which we demonstrate. We found most phenotypic variation to be quantitative and identified population, genotype, and phenotype associations. Importantly, we identified clinical origin associations. For example, we found that an introgressed PDR5 was present exclusively in clinical origin mosaic group strains; that the mosaic group was significantly enriched for clinical origin strains; and that clinical origin strains were much more copper resistant, suggesting that copper resistance contributes to fitness in the human host. The 100-genomes strains are a novel, multipurpose resource to advance the study of S. cerevisiae population genetics, quantitative genetics, and the emergence of an opportunistic pathogen.
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Affiliation(s)
- Pooja K Strope
- Duke University Medical Center, Department of Molecular Genetics and Microbiology, Durham, North Carolina 27710, USA
| | - Daniel A Skelly
- Department of Biology, Duke University, Durham, North Carolina 27710, USA
| | - Stanislav G Kozmin
- Duke University Medical Center, Department of Molecular Genetics and Microbiology, Durham, North Carolina 27710, USA
| | - Gayathri Mahadevan
- Duke University Medical Center, Department of Molecular Genetics and Microbiology, Durham, North Carolina 27710, USA
| | - Eric A Stone
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Paul M Magwene
- Department of Biology, Duke University, Durham, North Carolina 27710, USA
| | - Fred S Dietrich
- Duke University Medical Center, Department of Molecular Genetics and Microbiology, Durham, North Carolina 27710, USA
| | - John H McCusker
- Duke University Medical Center, Department of Molecular Genetics and Microbiology, Durham, North Carolina 27710, USA
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Liti G. The fascinating and secret wild life of the budding yeast S. cerevisiae. eLife 2015; 4. [PMID: 25807086 PMCID: PMC4373461 DOI: 10.7554/elife.05835] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/09/2015] [Indexed: 12/18/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae has been used in laboratory experiments for over a century and has been instrumental in understanding virtually every aspect of molecular biology and genetics. However, it wasn't until a decade ago that the scientific community started to realise how little was known about this yeast's ecology and natural history, and how this information was vitally important for interpreting its biology. Recent large-scale population genomics studies coupled with intensive field surveys have revealed a previously unappreciated wild lifestyle of S. cerevisiae outside the restrictions of human environments and laboratories. The recent discovery that Chinese isolates harbour almost twice as much genetic variation as isolates from the rest of the world combined suggests that Asia is the likely origin of the modern budding yeast. DOI:http://dx.doi.org/10.7554/eLife.05835.001
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Affiliation(s)
- Gianni Liti
- Institute for Research on Cancer and Ageing of Nice, CNRS UMR 7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
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30
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Goddard MR, Greig D. Saccharomyces cerevisiae: a nomadic yeast with no niche? FEMS Yeast Res 2015; 15:fov009. [PMID: 25725024 PMCID: PMC4444983 DOI: 10.1093/femsyr/fov009] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2015] [Indexed: 01/15/2023] Open
Abstract
Different species are usually thought to have specific adaptations, which allow them to occupy different ecological niches. But recent neutral ecology theory suggests that species diversity can simply be the result of random sampling, due to finite population sizes and limited dispersal. Neutral models predict that species are not necessarily adapted to specific niches, but are functionally equivalent across a range of habitats. Here, we evaluate the ecology of Saccharomyces cerevisiae, one of the most important microbial species in human history. The artificial collection, concentration and fermentation of large volumes of fruit for alcohol production produce an environment in which S. cerevisiae thrives, and therefore it is assumed that fruit is the ecological niche that S. cerevisiae inhabits and has adapted to. We find very little direct evidence that S. cerevisiae is adapted to fruit, or indeed to any other specific niche. We propose instead a neutral nomad model for S. cerevisiae, which we believe should be used as the starting hypothesis in attempting to unravel the ecology of this important microbe. It is assumed that Saccharomyces cerevisiae is adapted to inhabit fruits; however, we find very little evidence for adaptation to any niche. Instead, we propose a neutral nomad model for S. cerevisiae.
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Affiliation(s)
- Matthew R Goddard
- The School of Biological Sciences, the University of Auckland, Auckland 1142, New Zealand The School of Life Sciences, the University of Lincoln, Lincoln LN6 7DL, UK
| | - Duncan Greig
- Max Planck Institute for Evolutionary Biology, Plön 24306, Germany Department of Genetics, Evolution, and Environment, University College London, London WC1E 6BT, UK
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31
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Call for a California Coccidioidomycosis Consortium to Face the Top Ten Challenges Posed by a Recalcitrant Regional Disease. Mycopathologia 2014; 179:1-9. [DOI: 10.1007/s11046-014-9816-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 09/17/2014] [Indexed: 10/24/2022]
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32
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Leducq JB. Ecological Genomics of Adaptation and Speciation in Fungi. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 781:49-72. [DOI: 10.1007/978-94-007-7347-9_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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33
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Bañuls AL, Thomas F, Renaud F. Of parasites and men. INFECTION GENETICS AND EVOLUTION 2013; 20:61-70. [PMID: 23954419 DOI: 10.1016/j.meegid.2013.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/05/2013] [Accepted: 08/07/2013] [Indexed: 01/14/2023]
Abstract
The living world has evolved and is evolving through interspecific relationships between organisms. The diversity of these interactions is enormous going from mutualism to parasitism. Humans live with a multitude of microorganisms, essential for their biology. However, interactions are not always advantageous. Indeed, many organisms might become pathogens, such as the Plasmodium species, the causative agents of malaria. Like many other microorganisms, they are «Machiavellian» in their capacity to elaborate a range of reproduction strategies, giving them a huge advantage in terms of adaptation. Here, we discuss the role played by parasites in the ecology and evolution of living organisms and particularly of humans. In the study of infectious diseases, humans are legitimately the focal point, although they represent only one ecosystem among many others and not taking this into account certainly biases our global view of the system. Indeed, we know only a minimal fraction of the microorganisms we live with. However, parasites have shaped and are still shaping the human genome. Several genetic signatures are the proofs of the selection pressures by parasites that humankind has endured during its evolution. But, ultimately, what are the solutionsfor living with pathogens? Should we eradicate them or should we learn how to control and manage them?
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Affiliation(s)
- Anne-Laure Bañuls
- Laboratoire MIVEGEC (UMR CNRS 5290-IRD 224 - Universités Montpellier 1 et 2), Institut de Recherche pour le Développement (IRD), PO Box 64501, 34394 Montpellier, France.
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34
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Dalman K, Himmelstrand K, Olson Å, Lind M, Brandström-Durling M, Stenlid J. A genome-wide association study identifies genomic regions for virulence in the non-model organism Heterobasidion annosum s.s. PLoS One 2013; 8:e53525. [PMID: 23341945 PMCID: PMC3547014 DOI: 10.1371/journal.pone.0053525] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/03/2012] [Indexed: 12/02/2022] Open
Abstract
The dense single nucleotide polymorphisms (SNP) panels needed for genome wide association (GWA) studies have hitherto been expensive to establish and use on non-model organisms. To overcome this, we used a next generation sequencing approach to both establish SNPs and to determine genotypes. We conducted a GWA study on a fungal species, analysing the virulence of Heterobasidion annosum s.s., a necrotrophic pathogen, on its hosts Picea abies and Pinus sylvestris. From a set of 33,018 single nucleotide polymorphisms (SNP) in 23 haploid isolates, twelve SNP markers distributed on seven contigs were associated with virulence (P<0.0001). Four of the contigs harbour known virulence genes from other fungal pathogens and the remaining three harbour novel candidate genes. Two contigs link closely to virulence regions recognized previously by QTL mapping in the congeneric hybrid H. irregulare × H. occidentale. Our study demonstrates the efficiency of GWA studies for dissecting important complex traits of small populations of non-model haploid organisms with small genomes.
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Affiliation(s)
- Kerstin Dalman
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
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Abstract
Domesticated organisms demonstrate our capacity to influence wild species but also provide us with the opportunity to understand rapid evolution in the context of substantially altered environments and novel selective pressures. Recent advances in genetics and genomics have brought unprecedented insights into the domestication of many organisms and have opened new avenues for further improvements to be made. Yet, our ability to engineer biological systems is not without limits; genetic manipulation is often quite difficult. The budding yeast, Saccharomyces cerevisiae, is not only one of the most powerful model organisms, but is also the premier producer of fermented foods and beverages around the globe. As a model system, it entertains a hefty workforce dedicated to deciphering its genome and the function it encodes at a rich mechanistic level. As a producer, it is used to make leavened bread, and dozens of different alcoholic beverages, such as beer and wine. Yet, applying the awesome power of yeast genetics to understanding its origins and evolution requires some knowledge of its wild ancestors and the environments from which they were derived. A number of surprisingly diverse lineages of S. cerevisiae from both primeval and secondary forests in China have been discovered by Wang and his colleagues. These lineages substantially expand our knowledge of wild yeast diversity and will be a boon to elucidating the ecology, evolution and domestication of this academic and industrial workhorse.
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Affiliation(s)
- Justin C Fay
- Department of Genetics and Center for Genome Sciences and Systems Biology, Washington University, St. Louis, MO 63108, USA.
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36
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Prasad R, Goffeau A. Yeast ATP-Binding Cassette Transporters Conferring Multidrug Resistance. Annu Rev Microbiol 2012; 66:39-63. [DOI: 10.1146/annurev-micro-092611-150111] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Rajendra Prasad
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India;
| | - Andre Goffeau
- Institut des Sciences de la Vie, Université Catholique de Louvain, Louvain-la-Neuve, 1349 Belgium;
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37
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Magditch DA, Liu TB, Xue C, Idnurm A. DNA mutations mediate microevolution between host-adapted forms of the pathogenic fungus Cryptococcus neoformans. PLoS Pathog 2012; 8:e1002936. [PMID: 23055925 PMCID: PMC3464208 DOI: 10.1371/journal.ppat.1002936] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Accepted: 08/15/2012] [Indexed: 11/30/2022] Open
Abstract
The disease cryptococcosis, caused by the fungus Cryptococcus neoformans, is acquired directly from environmental exposure rather than transmitted person-to-person. One explanation for the pathogenicity of this species is that interactions with environmental predators select for virulence. However, co-incubation of C. neoformans with amoeba can cause a “switch” from the normal yeast morphology to a pseudohyphal form, enabling fungi to survive exposure to amoeba, yet conversely reducing virulence in mammalian models of cryptococcosis. Like other human pathogenic fungi, C. neoformans is capable of microevolutionary changes that influence the biology of the organism and outcome of the host-pathogen interaction. A yeast-pseudohyphal phenotypic switch also happens under in vitro conditions. Here, we demonstrate that this morphological switch, rather than being under epigenetic control, is controlled by DNA mutation since all pseudohyphal strains bear mutations within genes encoding components of the RAM pathway. High rates of isolation of pseudohyphal strains can be explained by the physical size of RAM pathway genes and a hypermutator phenotype of the strain used in phenotypic switching studies. Reversion to wild type yeast morphology in vitro or within a mammalian host can occur through different mechanisms, with one being counter-acting mutations. Infection of mice with RAM mutants reveals several outcomes: clearance of the infection, asymptomatic maintenance of the strains, or reversion to wild type forms and progression of disease. These findings demonstrate a key role of mutation events in microevolution to modulate the ability of a fungal pathogen to cause disease. Many diseases are contracted from the environment, rather than from sick people. It is unclear why those species are able to cause disease, since the selective pressures in the environment are presumed to be very different from those found within the host. Cryptococcus neoformans is a fungus that causes life-threatening lung and central nervous system disease in approximately one million people each year. The fungus is inhaled from environmental sources. One hypothesis to account for C. neoformans virulence is that amoeba are predators for this fungus, and surviving strains are pre-selected to be virulent in the human host. On the other hand, experiments have found that amoeba eat C. neoformans. A pseudohyphal cell type can survive, and while protecting against amoeba these cells are unable to cause disease in mouse models. We predicted that the pseudohyphal morphology reflected a change in function of a pathway of genes, and found that all pseudohyphal isolates contain mutations within genes for this pathway. The pseudohyphal trait is unstable, with reversion to normal yeast growth by counter-acting mutations. These mutations can occur during the course of mammalian infection. Our results show that mutation events account for a microevolution system currently described as phenotypic switching, and that mutations, at least under experimental conditions, can regulate pathogen adaptation and influence its host range.
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Affiliation(s)
- Denise A. Magditch
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Tong-Bao Liu
- Public Health Research Institute Center, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, United States of America
| | - Chaoyang Xue
- Public Health Research Institute Center, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, United States of America
| | - Alexander Idnurm
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
- * E-mail:
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38
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Abstract
Advances in sequencing technology have enabled whole-genome sequences to be obtained from multiple individuals within species, particularly in model organisms with compact genomes. For example, 36 genome sequences of Saccharomyces cerevisiae are now publicly available, and SNP data are available for even larger collections of strains. One potential use of these resources is mapping the genetic basis of phenotypic variation through genome-wide association (GWA) studies, with the benefit that associated variants can be studied experimentally with greater ease than in outbred populations such as humans. Here, we evaluate the prospects of GWA studies in S. cerevisiae strains through extensive simulations and a GWA study of mitochondrial copy number. We demonstrate that the complex and heterogeneous patterns of population structure present in yeast populations can lead to a high type I error rate in GWA studies of quantitative traits, and that methods typically used to control for population stratification do not provide adequate control of the type I error rate. Moreover, we show that while GWA studies of quantitative traits in S. cerevisiae may be difficult depending on the particular set of strains studied, association studies to map cis-acting quantitative trait loci (QTL) and Mendelian phenotypes are more feasible. We also discuss sampling strategies that could enable GWA studies in yeast and illustrate the utility of this approach in Saccharomyces paradoxus. Thus, our results provide important practical insights into the design and interpretation of GWA studies in yeast, and other model organisms that possess complex patterns of population structure.
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Fraser HB, Levy S, Chavan A, Shah HB, Perez JC, Zhou Y, Siegal ML, Sinha H. Polygenic cis-regulatory adaptation in the evolution of yeast pathogenicity. Genome Res 2012; 22:1930-9. [PMID: 22645260 PMCID: PMC3460188 DOI: 10.1101/gr.134080.111] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The acquisition of new genes, via horizontal transfer or gene duplication/diversification, has been the dominant mechanism thus far implicated in the evolution of microbial pathogenicity. In contrast, the role of many other modes of evolution—such as changes in gene expression regulation—remains unknown. A transition to a pathogenic lifestyle has recently taken place in some lineages of the budding yeast Saccharomyces cerevisiae. Here we identify a module of physically interacting proteins involved in endocytosis that has experienced selective sweeps for multiple cis-regulatory mutations that down-regulate gene expression levels in a pathogenic yeast. To test if these adaptations affect virulence, we created a panel of single-allele knockout strains whose hemizygous state mimics the genes' adaptive down-regulations, and measured their virulence in a mammalian host. Despite having no growth advantage in standard laboratory conditions, nearly all of the strains were more virulent than their wild-type progenitor, suggesting that these adaptations likely played a role in the evolution of pathogenicity. Furthermore, genetic variants at these loci were associated with clinical origin across 88 diverse yeast strains, suggesting the adaptations may have contributed to the virulence of a wide range of clinical isolates. We also detected pleiotropic effects of these adaptations on a wide range of morphological traits, which appear to have been mitigated by compensatory mutations at other loci. These results suggest that cis-regulatory adaptation can occur at the level of physically interacting modules and that one such polygenic adaptation led to increased virulence during the evolution of a pathogenic yeast.
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Affiliation(s)
- Hunter B Fraser
- Department of Biology, Stanford University, Stanford, California 94305, USA.
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