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Schikora-Tamarit MÀ, Gabaldón T. Recent gene selection and drug resistance underscore clinical adaptation across Candida species. Nat Microbiol 2024; 9:284-307. [PMID: 38177305 PMCID: PMC10769879 DOI: 10.1038/s41564-023-01547-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 11/06/2023] [Indexed: 01/06/2024]
Abstract
Understanding how microbial pathogens adapt to treatments, humans and clinical environments is key to infer mechanisms of virulence, transmission and drug resistance. This may help improve therapies and diagnostics for infections with a poor prognosis, such as those caused by fungal pathogens, including Candida. Here we analysed genomic variants across approximately 2,000 isolates from six Candida species (C. glabrata, C. auris, C. albicans, C. tropicalis, C. parapsilosis and C. orthopsilosis) and identified genes under recent selection, suggesting a highly complex clinical adaptation. These involve species-specific and convergently affected adaptive mechanisms, such as adhesion. Using convergence-based genome-wide association studies we identified known drivers of drug resistance alongside potentially novel players. Finally, our analyses reveal an important role of structural variants and suggest an unexpected involvement of (para)sexual recombination in the spread of resistance. Our results provide insights on how opportunistic pathogens adapt to human-related environments and unearth candidate genes that deserve future attention.
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Affiliation(s)
- Miquel Àngel Schikora-Tamarit
- Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain.
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
- Centro Investigación Biomédica En Red de Enfermedades Infecciosas, Barcelona, Spain.
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2
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Genome plasticity in Candida albicans: A cutting-edge strategy for evolution, adaptation, and survival. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 99:105256. [PMID: 35231665 DOI: 10.1016/j.meegid.2022.105256] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/12/2021] [Accepted: 02/22/2022] [Indexed: 12/15/2022]
Abstract
Candida albicans is the most implicated fungal species that grows as a commensal or opportunistic pathogen in the human host. It is associated with many life-threatening infections, especially in immunocompromised persons. The genome of Candida albicans is very flexible and can withstand a wide assortment of variations in a continuously changing environment. Thus, genome plasticity is central to its adaptation and has long been of considerable interest. C. albicans has a diploid heterozygous genome that is highly dynamic and can display variation from small to large scale chromosomal rearrangement and aneuploidy, which have implications in drug resistance, virulence, and pathogenicity. This review presents an up-to-date overview of recent genomic studies involving C. albicans. It discusses the accumulating evidence that shows how mitotic recombination events, ploidy dynamics, aneuploidy, and loss of heterozygosity (LOH) influence evolution, adaptation, and survival in C. albicans. Understanding the factors that affect the genome is crucial for a proper understanding of species and rapid development and adjustment of therapeutic strategies to mitigate their spread.
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Lai WC, Hsu HC, Cheng CW, Wang SH, Li WC, Hsieh PS, Tseng TL, Lin TH, Shieh JC. Filament Negative Regulator CDC4 Suppresses Glycogen Phosphorylase Encoded GPH1 that Impacts the Cell Wall-Associated Features in Candida albicans. J Fungi (Basel) 2022; 8:jof8030233. [PMID: 35330235 PMCID: PMC8949380 DOI: 10.3390/jof8030233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023] Open
Abstract
We have previously identified Candida albicans GPH1 (orf19.7021) whose protein product was associated with C. albicans Cdc4. The GPH1 gene is a putative glycogen phosphorylase because its Saccharomyces cerevisiae homolog participates in glycogen catabolism, which involves the synthesis of β-glucan of the fungal cell wall. We made a strain whose CaCDC4 expression is repressed, and GPH1 is constitutively expressed. We established a GPH1 null mutant strain and used it to conduct the in vitro virulence assays that detect cell wall function. The in vitro virulence assay is centered on biofilm formation in which analytic procedures are implemented to evaluate cell surface hydrophobicity; competence, either in stress resistance, germ tube formation, or fibronection association; and the XTT-based adhesion and biofilm formation. We showed that the constitutively expressed GPH1 partially suppresses filamentation when the CaCDC4 expression is repressed. The C. albicans Gph1 protein is reduced in the presence of CaCdc4 in comparison with the absence of CaCdc4. Compared with the wild-type strain, the gph1Δ/gph1Δ mutant displayed a reduction in the capability to form germ tubes and the cell surface hydrophobicity but an increase in binding with fibronectin. Compared with the wild-type strain, the gph1Δ/gph1Δ mutant showed a rise in adhesion, the initial stage of biofilm formation, but displayed a similar capacity to form a mature biofilm. There was no major impact on the gph1Δ/gph1Δ mutant regarding the conditions of cell wall damaging and TOR pathway-associated nutrient depletion. We conclude that GPH1, adversely regulated by the filament suppressor CDC4, contributes to cell wall function in C. albicans.
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Affiliation(s)
- Wei-Chung Lai
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Hsiao-Chi Hsu
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Chun-Wen Cheng
- Institute of Medicine, Chung Shan Medical University, Taichung City 40201, Taiwan;
| | - Shao-Hung Wang
- Department of Microbiology, Immunology and Biopharmaceuticals, National Chiayi University, Chiayi 60004, Taiwan;
| | - Wan Chen Li
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Po-Szu Hsieh
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Tzu-Ling Tseng
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Ting-Hui Lin
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
| | - Jia-Ching Shieh
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan; (W.-C.L.); (H.-C.H.); (W.C.L.); (P.-S.H.); (T.-L.T.); (T.-H.L.)
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung City 40201, Taiwan
- Immunology Research Center, Chung Shan Medical University, Taichung City 40201, Taiwan
- Correspondence: ; Tel.: +886-424-730-022 (ext. 11806); Fax: +886-424-757-412
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4
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Di Cosola M, Cazzolla AP, Charitos IA, Ballini A, Inchingolo F, Santacroce L. Candida albicans and Oral Carcinogenesis. A Brief Review. J Fungi (Basel) 2021; 7:jof7060476. [PMID: 34204731 PMCID: PMC8231483 DOI: 10.3390/jof7060476] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/02/2021] [Accepted: 06/09/2021] [Indexed: 12/14/2022] Open
Abstract
Current medical knowledge and research on patients’ management are still evolving, and several protocols on minimizing risk of infection by Candida spp. among the population have developed. The aim of this work is to review the epidemiological and biomolecular characteristics and the various histopathological carcinogenesis hypothesis mechanisms that can occur during Candida albicans infections. Current evidence from the literature on the role of C. albicans during potentially malignant oral disorders and oral cancer has been sought. Thus, these biomolecular processes can give or contribute to benign lesions, also in precancerous or cancerous situations. Alongside this, the physiological microorganism oral flora (microbiota) can play a crucial role in maintaining oral health during those infections and therefore avoid carcinogenesis.
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Affiliation(s)
- Michele Di Cosola
- Department of Clinical and Experimental Medicine, Università degli Studi di Foggia, 71122 Foggia, Italy; (M.D.C.); (A.P.C.)
| | - Angela Pia Cazzolla
- Department of Clinical and Experimental Medicine, Università degli Studi di Foggia, 71122 Foggia, Italy; (M.D.C.); (A.P.C.)
| | - Ioannis Alexandros Charitos
- Department of Emergency and Urgency, National Poisoning Centre, Riuniti University Hospital of Foggia, 71122 Foggia, Italy
- Correspondence: (I.A.C.); (A.B.)
| | - Andrea Ballini
- Department of Biosciences, Biotechnologies and Biopharmaceutics, Campus Universitario Ernesto Quagliariello, University of Bari “Aldo Moro”, 70125 Bari, Italy
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro” School of Medicine, 70124 Bari, Italy; (F.I.); (L.S.)
- Correspondence: (I.A.C.); (A.B.)
| | - Francesco Inchingolo
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro” School of Medicine, 70124 Bari, Italy; (F.I.); (L.S.)
| | - Luigi Santacroce
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro” School of Medicine, 70124 Bari, Italy; (F.I.); (L.S.)
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d'Enfert C, Kaune AK, Alaban LR, Chakraborty S, Cole N, Delavy M, Kosmala D, Marsaux B, Fróis-Martins R, Morelli M, Rosati D, Valentine M, Xie Z, Emritloll Y, Warn PA, Bequet F, Bougnoux ME, Bornes S, Gresnigt MS, Hube B, Jacobsen ID, Legrand M, Leibundgut-Landmann S, Manichanh C, Munro CA, Netea MG, Queiroz K, Roget K, Thomas V, Thoral C, Van den Abbeele P, Walker AW, Brown AJP. The impact of the Fungus-Host-Microbiota interplay upon Candida albicans infections: current knowledge and new perspectives. FEMS Microbiol Rev 2021; 45:fuaa060. [PMID: 33232448 PMCID: PMC8100220 DOI: 10.1093/femsre/fuaa060] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/18/2020] [Indexed: 12/11/2022] Open
Abstract
Candida albicans is a major fungal pathogen of humans. It exists as a commensal in the oral cavity, gut or genital tract of most individuals, constrained by the local microbiota, epithelial barriers and immune defences. Their perturbation can lead to fungal outgrowth and the development of mucosal infections such as oropharyngeal or vulvovaginal candidiasis, and patients with compromised immunity are susceptible to life-threatening systemic infections. The importance of the interplay between fungus, host and microbiota in driving the transition from C. albicans commensalism to pathogenicity is widely appreciated. However, the complexity of these interactions, and the significant impact of fungal, host and microbiota variability upon disease severity and outcome, are less well understood. Therefore, we summarise the features of the fungus that promote infection, and how genetic variation between clinical isolates influences pathogenicity. We discuss antifungal immunity, how this differs between mucosae, and how individual variation influences a person's susceptibility to infection. Also, we describe factors that influence the composition of gut, oral and vaginal microbiotas, and how these affect fungal colonisation and antifungal immunity. We argue that a detailed understanding of these variables, which underlie fungal-host-microbiota interactions, will present opportunities for directed antifungal therapies that benefit vulnerable patients.
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Affiliation(s)
- Christophe d'Enfert
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Ann-Kristin Kaune
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Leovigildo-Rey Alaban
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Sayoni Chakraborty
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Neugasse 25, 07743 Jena, Germany
| | - Nathaniel Cole
- Gut Microbiology Group, Rowett Institute, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Margot Delavy
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Daria Kosmala
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Benoît Marsaux
- ProDigest BV, Technologiepark 94, B-9052 Gent, Belgium
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 9000 Ghent, Belgium
| | - Ricardo Fróis-Martins
- Immunology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zurich 8057, Switzerland
- Institute of Experimental Immunology, University of Zurich, Winterthurerstrasse 190, Zürich 8057, Switzerland
| | - Moran Morelli
- Mimetas, Biopartner Building 2, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands
| | - Diletta Rosati
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Marisa Valentine
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Zixuan Xie
- Gut Microbiome Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119–129, 08035 Barcelona, Spain
| | - Yoan Emritloll
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Peter A Warn
- Magic Bullet Consulting, Biddlecombe House, Ugbrook, Chudleigh Devon, TQ130AD, UK
| | - Frédéric Bequet
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Stephanie Bornes
- Université Clermont Auvergne, INRAE, VetAgro Sup, UMRF0545, 20 Côte de Reyne, 15000 Aurillac, France
| | - Mark S Gresnigt
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Bernhard Hube
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Ilse D Jacobsen
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Mélanie Legrand
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Salomé Leibundgut-Landmann
- Immunology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zurich 8057, Switzerland
- Institute of Experimental Immunology, University of Zurich, Winterthurerstrasse 190, Zürich 8057, Switzerland
| | - Chaysavanh Manichanh
- Gut Microbiome Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119–129, 08035 Barcelona, Spain
| | - Carol A Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Karla Queiroz
- Mimetas, Biopartner Building 2, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands
| | - Karine Roget
- NEXBIOME Therapeutics, 22 allée Alan Turing, 63000 Clermont-Ferrand, France
| | - Vincent Thomas
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
| | - Claudia Thoral
- NEXBIOME Therapeutics, 22 allée Alan Turing, 63000 Clermont-Ferrand, France
| | | | - Alan W Walker
- Gut Microbiology Group, Rowett Institute, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Alistair J P Brown
- MRC Centre for Medical Mycology, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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6
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Thomson GJ, Kakade P, Hirakawa MP, Ene IV, Bennett RJ. Adaptation to the dietary sugar D-tagatose via genome instability in polyploid Candida albicans cells. G3-GENES GENOMES GENETICS 2021; 11:6219300. [PMID: 33836061 PMCID: PMC8495922 DOI: 10.1093/g3journal/jkab110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
The opportunistic fungal pathogen Candida albicans undergoes an unusual parasexual cycle wherein diploid cells mate to form tetraploid cells that can generate genetically diverse progeny via a non-meiotic program of chromosome loss. The genetic diversity afforded by parasex impacts clinically relevant features including drug resistance and virulence, and yet the factors influencing genome instability in C. albicans are not well defined. To understand how environmental cues impact genome instability, we monitored ploidy change following tetraploid cell growth in a panel of different carbon sources. We found that growth in one carbon source, D-tagatose, led to high levels of genomic instability and chromosome loss in tetraploid cells. This sugar is a stereoisomer of L-sorbose which was previously shown to promote karyotypic changes in C. albicans. However, while expression of the SOU1 gene enabled utilization of L-sorbose, overexpression of this gene did not promote growth in D-tagatose, indicating differences in assimilation of the two sugars. In addition, genome sequencing of multiple progeny recovered from D-tagatose cultures revealed increased relative copy numbers of chromosome 4, suggestive of chromosome-level regulation of D-tagatose metabolism. Together, these studies identify a novel environmental cue that induces genome instability in C. albicans, and further implicate chromosomal changes in supporting metabolic adaptation in this species.
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Affiliation(s)
- Gregory J Thomson
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA
| | - Pallavi Kakade
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA
| | - Matthew P Hirakawa
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA.,Department of Systems Biology, Sandia National Laboratories, Livermore, CA 94550, USA
| | - Iuliana V Ene
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA.,Mycology Department, Pasteur Institute, Paris 75015, France
| | - Richard J Bennett
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA
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Abstract
Diversity within the fungal kingdom is evident from the wide range of morphologies fungi display as well as the various ecological roles and industrial purposes they serve. Technological advances, particularly in long-read sequencing, coupled with the increasing efficiency and decreasing costs across sequencing platforms have enabled robust characterization of fungal genomes. These sequencing efforts continue to reveal the rampant diversity in fungi at the genome level. Here, we discuss studies that have furthered our understanding of fungal genetic diversity and genomic evolution. These studies revealed the presence of both small-scale and large-scale genomic changes. In fungi, research has recently focused on many small-scale changes, such as how hypermutation and allelic transmission impact genome evolution as well as how and why a few specific genomic regions are more susceptible to rapid evolution than others. High-throughput sequencing of a diverse set of fungal genomes has also illuminated the frequency, mechanisms, and impacts of large-scale changes, which include chromosome structural variation and changes in chromosome number, such as aneuploidy, polyploidy, and the presence of supernumerary chromosomes. The studies discussed herein have provided great insight into how the architecture of the fungal genome varies within species and across the kingdom and how modern fungi may have evolved from the last common fungal ancestor and might also pave the way for understanding how genomic diversity has evolved in all domains of life.
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Affiliation(s)
- Shelby J. Priest
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Vikas Yadav
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
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8
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Abstract
Advances in our understanding of molecular mechanisms of tumorigenesis have translated into knowledge-based therapies directed against specific oncogenic signaling targets. These therapies often induce dramatic responses in susceptible tumors. Unfortunately, most advanced cancers, including those with robust initial responses, eventually acquire resistance to targeted therapies and relapse. Even though immune-based therapies are more likely to achieve complete cures, acquired resistance remains an obstacle to their success as well. Acquired resistance is the direct consequence of pre-existing intratumor heterogeneity and ongoing diversification during therapy, which enables some tumor cells to survive treatment and facilitates the development of new therapy-resistant phenotypes. In this review, we discuss the sources of intratumor heterogeneity and approaches to capture and account for it during clinical decision making. Finally, we outline potential strategies to improve therapeutic outcomes by directly targeting intratumor heterogeneity.
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Affiliation(s)
- Andriy Marusyk
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Michalina Janiszewska
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Kornelia Polyak
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
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9
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Facilitators of adaptation and antifungal resistance mechanisms in clinically relevant fungi. Fungal Genet Biol 2019; 132:103254. [PMID: 31326470 DOI: 10.1016/j.fgb.2019.103254] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 12/12/2022]
Abstract
Opportunistic fungal pathogens can cause a diverse range of diseases in humans. The increasing rate of fungal infections caused by strains that are resistant to commonly used antifungals results in difficulty to treat diseases, with accompanying high mortality rates. Existing and newly emerging molecular resistance mechanisms rapidly spread in fungal populations and need to be monitored. Fungi exhibit a diversity of mechanisms to maintain physiological resilience and create genetic variation; processes which eventually lead to the selection and spread of resistant fungal pathogens. To prevent and anticipate this dispersion, the role of evolutionary factors that drive fungal adaptation should be investigated. In this review, we provide an overview of resistance mechanisms against commonly used antifungal compounds in the clinic and for which fungal resistance has been reported. Furthermore, we aim to summarize and elucidate potent generators of genetic variability across the fungal kingdom that aid adaptation to stressful environments. This knowledge can lead to recognizing potential niches that facilitate fast resistance development and can provide leads for new management strategies to battle the emerging resistant populations in the clinic and the environment.
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10
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Legrand M, Jaitly P, Feri A, d'Enfert C, Sanyal K. Candida albicans: An Emerging Yeast Model to Study Eukaryotic Genome Plasticity. Trends Genet 2019; 35:292-307. [PMID: 30826131 DOI: 10.1016/j.tig.2019.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/25/2019] [Accepted: 01/25/2019] [Indexed: 01/07/2023]
Abstract
Saccharomyces cerevisiae and Schizosaccharomyces pombe have served as uncontested unicellular model organisms, as major discoveries made in the field of genome biology using yeast genetics have proved to be relevant from yeast to humans. The yeast Candida albicans has attracted much attention because of its ability to switch between a harmless commensal and a dreaded human pathogen. C. albicans bears unique features regarding its life cycle, genome structure, and dynamics, and their links to cell biology and adaptation to environmental challenges. Examples include a unique reproduction cycle with haploid, diploid, and tetraploid forms; a distinctive organisation of chromosome hallmarks; a highly dynamic genome, with extensive karyotypic variations, including aneuploidies, isochromosome formation, and loss-of-heterozygosity; and distinctive links between the response to DNA alterations and cell morphology. These features have made C. albicans emerge as a new and attractive unicellular model to study genome biology and dynamics in eukaryotes.
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Affiliation(s)
- Mélanie Legrand
- Fungal Biology and Pathogenicity Unit, Department of Mycology, Institut Pasteur, INRA, Paris, France
| | - Priya Jaitly
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Adeline Feri
- Fungal Biology and Pathogenicity Unit, Department of Mycology, Institut Pasteur, INRA, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France; Current address: Pathoquest, BioPark, 11 rue Watt, 75013 Paris, France
| | - Christophe d'Enfert
- Fungal Biology and Pathogenicity Unit, Department of Mycology, Institut Pasteur, INRA, Paris, France.
| | - Kaustuv Sanyal
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India.
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Lee YT, Fang YY, Sun YW, Hsu HC, Weng SM, Tseng TL, Lin TH, Shieh JC. THR1 mediates GCN4 and CDC4 to link morphogenesis with nutrient sensing and the stress response in Candida albicans. Int J Mol Med 2018; 42:3193-3208. [PMID: 30320368 PMCID: PMC6202100 DOI: 10.3892/ijmm.2018.3930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/08/2018] [Indexed: 12/31/2022] Open
Abstract
Candida albicans (C. albicans) CDC4 (CaCDC4), encoding the F-box protein for the substrate specificity of the Skp1-cullin-F-box E3 ubiquitin ligase complex, suppresses the yeast-to-filament transition in C. albicans. In our previous study, Thr1 was identified as a CaCdc4-associated protein using affinity purification. THR1 encodes a homoserine kinase, which is involved in the threonine biosynthesis pathway. The present study generated a strain with repressible CaCDC4 expression and continuous THR1 expression. Colony and cell morphology analyses, as well as immunoblotting, revealed that the Thr1 protein was detectable under conditions in which the expression of CaCDC4 was repressed and that the filaments resulting from the repressed expression of CaCDC4 were suppressed by the constitutive expression of THR1 in C. albicans. Additionally, by using the CaSAT1-flipper method, the present study produced null mutants of THR1, GCN4, and CaCDC4. The phenotypic consequences were evaluated by growth curves, spotting assays, microscopic analysis, reverse transcription-polymerase chain reaction and XTT-based biofilm formation ability. The results revealed that fewer cells lacking THR1 entered the stationary phase but had no apparent morphological alteration. It was observed that the expression of THR1 was upregulated concurrently with GCN4 during nutrient depletion and that cells lacking GCN4 rescued the lethality of cells in the absence of THR1 in conditions accumulating homoserine in the threonine biosynthesis pathway. Of note, it was found that cells with either CaCDC4 or THR1 loss were sensitive to oxidative stress and osmotic stress, with those with THR1 loss being more sensitive. In addition, it was observed that cells with loss of either CaCDC4 or THR1 exhibited the ability to increase biofilm formation, with those lacking CaCDC4 exhibiting a greater extent of enhancement. It was concluded that CaCDC4 is important in the coordination of morphogenesis, nutrient sensing, and the stress response through THR1 in C. albicans.
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Affiliation(s)
- Yuan-Ti Lee
- Institute of Medicine and School of Medicine, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Yi-Ya Fang
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Yu Wen Sun
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Hsiao-Chi Hsu
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Shan-Mei Weng
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Tzu-Ling Tseng
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Ting-Hui Lin
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
| | - Jia-Ching Shieh
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 40201, Taiwan, R.O.C
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12
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The Genome of the Human Pathogen Candida albicans Is Shaped by Mutation and Cryptic Sexual Recombination. mBio 2018; 9:mBio.01205-18. [PMID: 30228236 PMCID: PMC6143739 DOI: 10.1128/mbio.01205-18] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The opportunistic fungal pathogen Candida albicans lacks a conventional sexual program and is thought to evolve, at least primarily, through the clonal acquisition of genetic changes. Here, we performed an analysis of heterozygous diploid genomes from 21 clinical isolates to determine the natural evolutionary processes acting on the C. albicans genome. Mutation and recombination shaped the genomic landscape among the C. albicans isolates. Strain-specific single nucleotide polymorphisms (SNPs) and insertions/deletions (indels) clustered across the genome. Additionally, loss-of-heterozygosity (LOH) events contributed substantially to genotypic variation, with most long-tract LOH events extending to the ends of the chromosomes suggestive of repair via break-induced replication. Consistent with a model of inheritance by descent, most polymorphisms were shared between closely related strains. However, some isolates contained highly mosaic genomes consistent with strains having experienced interclade recombination during their evolutionary history. A detailed examination of mitochondrial genomes also revealed clear examples of interclade recombination among sequenced strains. These analyses therefore establish that both (para)sexual recombination and mitotic mutational processes drive evolution of this important pathogen. To further facilitate the study of C. albicans genomes, we also introduce an online platform, SNPMap, to examine SNP patterns in sequenced isolates.IMPORTANCE Mutations introduce variation into the genome upon which selection can act. Defining the nature of these changes is critical for determining species evolution, as well as for understanding the genetic changes driving important cellular processes. The heterozygous diploid fungus Candida albicans is both a frequent commensal organism and a prevalent opportunistic pathogen. A prevailing theory is that C. albicans evolves primarily through the gradual buildup of mitotic mutations, and a pressing issue is whether sexual or parasexual processes also operate within natural populations. Here, we establish that the C. albicans genome evolves by a combination of localized mutation and both short-tract and long-tract loss-of-heterozygosity (LOH) events within the sequenced isolates. Mutations are more prevalent within noncoding and heterozygous regions and LOH increases towards chromosome ends. Furthermore, we provide evidence for genetic exchange between isolates, establishing that sexual or parasexual processes have contributed to the diversity of both nuclear and mitochondrial genomes.
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Biological Roles of Protein-Coding Tandem Repeats in the Yeast Candida Albicans. J Fungi (Basel) 2018; 4:jof4030078. [PMID: 29966250 PMCID: PMC6162428 DOI: 10.3390/jof4030078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/16/2018] [Accepted: 06/27/2018] [Indexed: 01/07/2023] Open
Abstract
Tandem repeat (TR) DNA mutates faster than other DNA by insertion and deletion of repeats. Large parts of eukaryotic proteomes are encoded by ORFs containing protein-coding TRs (TR-ORFs, pcTRs) with largely unknown biological consequences. We explored these in the yeast Candida albicans, an opportunistic human pathogen. We found that almost half of C. albicans’ proteins are encoded by TR-ORFs. pcTR frequency differed only moderately between different gene (GO) categories. Bioinformatic predictions of genome-wide mutation rates and clade-specific differences in pcTR allele frequencies indicated that pcTRs (i) significantly increase the genome-wide mutation rate; (ii) significantly impact on fitness and (iii) allow the evolution of selectively advantageous clade-specific protein variants. Synonymous mutations reduced the repetitiveness of many amino acid repeat-encoding pcTRs. A survey, in 58 strains, revealed that in some pcTR regions in which repetitiveness was not significantly diminished by synonymous mutations the habitat predicted which alleles were present, suggesting roles of pcTR mutation in short-term adaptation and pathogenesis. In C. albicans pcTR mutation apparently is an important mechanism for mutational advance and possibly also rapid adaptation, with synonymous mutations providing a mechanism for adjusting mutation rates of individual pcTRs. Analyses of Arabidopsis and human pcTRs showed that the latter also occurs in other eukaryotes.
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Gene flow contributes to diversification of the major fungal pathogen Candida albicans. Nat Commun 2018; 9:2253. [PMID: 29884848 PMCID: PMC5993739 DOI: 10.1038/s41467-018-04787-4] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/23/2018] [Indexed: 12/11/2022] Open
Abstract
Elucidating population structure and levels of genetic diversity and recombination is necessary to understand the evolution and adaptation of species. Candida albicans is the second most frequent agent of human fungal infections worldwide, causing high-mortality rates. Here we present the genomic sequences of 182 C. albicans isolates collected worldwide, including commensal isolates, as well as ones responsible for superficial and invasive infections, constituting the largest dataset to date for this major fungal pathogen. Although, C. albicans shows a predominantly clonal population structure, we find evidence of gene flow between previously known and newly identified genetic clusters, supporting the occurrence of (para)sexuality in nature. A highly clonal lineage, which experimentally shows reduced fitness, has undergone pseudogenization in genes required for virulence and morphogenesis, which may explain its niche restriction. Candida albicans thus takes advantage of both clonality and gene flow to diversify. The fungal pathogen Candida albicans can undergo a parasexual process that may contribute to genetic diversity, but its actual relevance is unclear. Here, Ropars et al. analyse the genomic sequences of 182 C. albicans isolates collected worldwide and find evidence of gene flow and thus parasexuality in nature.
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15
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Nieuwenhuis BPS, James TY. The frequency of sex in fungi. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0540. [PMID: 27619703 DOI: 10.1098/rstb.2015.0540] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2016] [Indexed: 12/16/2022] Open
Abstract
Fungi are a diverse group of organisms with a huge variation in reproductive strategy. While almost all species can reproduce sexually, many reproduce asexually most of the time. When sexual reproduction does occur, large variation exists in the amount of in- and out-breeding. While budding yeast is expected to outcross only once every 10 000 generations, other fungi are obligate outcrossers with well-mixed panmictic populations. In this review, we give an overview of the costs and benefits of sexual and asexual reproduction in fungi, and the mechanisms that evolved in fungi to reduce the costs of either mode. The proximate molecular mechanisms potentiating outcrossing and meiosis appear to be present in nearly all fungi, making them of little use for predicting outcrossing rates, but also suggesting the absence of true ancient asexual lineages. We review how population genetic methods can be used to estimate the frequency of sex in fungi and provide empirical data that support a mixed mode of reproduction in many species with rare to frequent sex in between rounds of mitotic reproduction. Finally, we highlight how these estimates might be affected by the fungus-specific mechanisms that evolved to reduce the costs of sexual and asexual reproduction.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
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Affiliation(s)
- Bart P S Nieuwenhuis
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, 830 North University, Ann Arbor, MI 48109-1048, USA
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16
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Boral H, Metin B, Döğen A, Seyedmousavi S, Ilkit M. Overview of selected virulence attributes in Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, and Exophiala dermatitidis. Fungal Genet Biol 2017; 111:92-107. [PMID: 29102684 DOI: 10.1016/j.fgb.2017.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
The incidence of fungal diseases has been increasing since 1980, and is associated with excessive morbidity and mortality, particularly among immunosuppressed patients. Of the known 625 pathogenic fungal species, infections caused by the genera Aspergillus, Candida, Cryptococcus, and Trichophyton are responsible for more than 300 million estimated episodes of acute or chronic infections worldwide. In addition, a rather neglected group of opportunistic fungi known as black yeasts and their filamentous relatives cause a wide variety of recalcitrant infections in both immunocompetent and immunosuppressed hosts. This article provides an overview of selected virulence factors that are known to suppress host immunity and enhance the infectivity of these fungi.
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Affiliation(s)
- Hazal Boral
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey
| | - Banu Metin
- Department of Food Engineering, Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, Istanbul, Turkey
| | - Aylin Döğen
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey
| | - Seyedmojtaba Seyedmousavi
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands; Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Center of Excellence for Infection Biology and Antimicrobial Pharmacology, Tehran, Iran
| | - Macit Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey.
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Parasex Generates Phenotypic Diversity de Novo and Impacts Drug Resistance and Virulence in Candida albicans. Genetics 2017; 207:1195-1211. [PMID: 28912344 DOI: 10.1534/genetics.117.300295] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/05/2017] [Indexed: 01/06/2023] Open
Abstract
Candida albicans is a diploid fungus that is a frequent cause of mucosal and systemic infections in humans. This species exhibits an unusual parasexual cycle in which mating produces tetraploid cells that undergo a nonmeiotic program of concerted chromosome loss to return to a diploid or aneuploid state. In this work, we used a multipronged approach to examine the capacity of parasex to generate diversity in C. albicans First, we compared the phenotypic properties of 32 genotyped progeny and observed wide-ranging differences in fitness, filamentation, biofilm formation, and virulence. Strikingly, one parasexual isolate displayed increased virulence relative to parental strains using a Galleria mellonella model of infection, establishing that parasex has the potential to enhance pathogenic traits. Next, we examined parasexual progeny derived from homothallic, same-sex mating events, and reveal that parasex can generate diversity de novo from identical parental strains. Finally, we generated pools of parasexual progeny and examined resistance of these pools to environmental stresses. Parasexual progeny were generally less fit than control strains across most test conditions, but showed an increased ability to grow in the presence of the antifungal drug fluconazole (FL). FL-resistant progeny were aneuploid isolates, often being diploid strains trisomic for both Chr3 and Chr6. Passaging of these aneuploid strains frequently led to loss of the supernumerary chromosomes and a concomitant decrease in drug resistance. These experiments establish that parasex generates extensive phenotypic diversity de novo, and that this process has important consequences for both virulence and drug resistance in C. albicans populations.
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18
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Tao Y, Mace ES, Tai S, Cruickshank A, Campbell BC, Zhao X, Van Oosterom EJ, Godwin ID, Botella JR, Jordan DR. Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops. FRONTIERS IN PLANT SCIENCE 2017. [PMID: 28769949 DOI: 10.3389/fp/s.2017.01237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.
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Affiliation(s)
- Yongfu Tao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Emma S Mace
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | | | - Alan Cruickshank
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | - Bradley C Campbell
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Xianrong Zhao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Erik J Van Oosterom
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandBrisbane, QLD, Australia
| | - Ian D Godwin
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Jose R Botella
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - David R Jordan
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
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19
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Tao Y, Mace ES, Tai S, Cruickshank A, Campbell BC, Zhao X, Van Oosterom EJ, Godwin ID, Botella JR, Jordan DR. Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops. FRONTIERS IN PLANT SCIENCE 2017; 8:1237. [PMID: 28769949 PMCID: PMC5513986 DOI: 10.3389/fpls.2017.01237] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 06/30/2017] [Indexed: 05/22/2023]
Abstract
Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.
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Affiliation(s)
- Yongfu Tao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- *Correspondence: Yongfu Tao
| | - Emma S. Mace
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
- Emma S. Mace
| | | | - Alan Cruickshank
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | - Bradley C. Campbell
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Xianrong Zhao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Erik J. Van Oosterom
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandBrisbane, QLD, Australia
| | - Ian D. Godwin
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Jose R. Botella
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - David R. Jordan
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- David R. Jordan
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Phenotypic Profiling Reveals that Candida albicans Opaque Cells Represent a Metabolically Specialized Cell State Compared to Default White Cells. mBio 2016; 7:mBio.01269-16. [PMID: 27879329 PMCID: PMC5120136 DOI: 10.1128/mbio.01269-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The white-opaque switch is a bistable, epigenetic transition affecting multiple traits in Candida albicans including mating, immunogenicity, and niche specificity. To compare how the two cell states respond to external cues, we examined the fitness, phenotypic switching, and filamentation properties of white cells and opaque cells under 1,440 different conditions at 25°C and 37°C. We demonstrate that white and opaque cells display striking differences in their integration of metabolic and thermal cues, so that the two states exhibit optimal fitness under distinct conditions. White cells were fitter than opaque cells under a wide range of environmental conditions, including growth at various pHs and in the presence of chemical stresses or antifungal drugs. This difference was exacerbated at 37°C, consistent with white cells being the default state of C. albicans in the mammalian host. In contrast, opaque cells showed greater fitness than white cells under select nutritional conditions, including growth on diverse peptides at 25°C. We further demonstrate that filamentation is significantly rewired between the two states, with white and opaque cells undergoing filamentous growth in response to distinct external cues. Genetic analysis was used to identify signaling pathways impacting the white-opaque transition both in vitro and in a murine model of commensal colonization, and three sugar sensing pathways are revealed as regulators of the switch. Together, these findings establish that white and opaque cells are programmed for differential integration of metabolic and thermal cues and that opaque cells represent a more metabolically specialized cell state than the default white state. IMPORTANCE Epigenetic transitions are an important mechanism by which microbes adapt to external stimuli. For Candida albicans, such transitions are crucial for adaptation to complex, fluctuating environments, and therefore contribute to its success as a human pathogen. The white-opaque switch modulates multiple C. albicans attributes, from sexual competency to niche specificity. Here, we demonstrate that metabolic circuits are extensively rewired between white and opaque states, so that the two cell types exhibit optimal fitness under different nutritional conditions and at different temperatures. We thereby establish that epigenetic events can profoundly alter the metabolism of fungal cells. We also demonstrate that epigenetic switching regulates filamentation and biofilm formation, two phenotypes closely associated with pathogenesis. These experiments reveal that white cells, considered the most clinically relevant form of C. albicans, are a "general-purpose" state suited to many environments, whereas opaque cells appear to represent a more metabolically specialized form of the species.
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Boyles RE, Cooper EA, Myers MT, Brenton Z, Rauh BL, Morris GP, Kresovich S. Genome-Wide Association Studies of Grain Yield Components in Diverse Sorghum Germplasm. THE PLANT GENOME 2016; 9. [PMID: 27898823 DOI: 10.3835/plantgenome2015.09.0091] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Grain yield and its primary determinants, grain number and weight, are important traits in cereal crops that have been well studied; however, the genetic basis of and interactions between these traits remain poorly understood. Characterization of grain yield per primary panicle (YPP), grain number per primary panicle (GNP), and 1000-grain weight (TGW) in sorghum [ (L.) Moench], a hardy C cereal with a genome size of ∼730 Mb, was implemented in a diversity panel containing 390 accessions. These accessions were genotyped to obtain 268,830 single-nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) were performed to identify loci associated with each grain yield component and understand the genetic interactions between these traits. Genome-wide association studies identified associations across the genome with YPP, GNP, and TGW that were located within previously mapped sorghum QTL for panicle weight, grain yield, and seed size, respectively. There were no significant associations between GNP and TGW that were within 100 kb, much greater than the average linkage disequilibrium (LD) in sorghum. The identification of nonoverlapping loci for grain number and weight suggests these traits may be manipulated independently to increase the grain yield of sorghum. Following GWAS, genomic regions surrounding each associated SNP were mined for candidate genes. Previously published expression data indicated several TGW candidate genes, including an ethylene receptor homolog, were primarily expressed within developing seed tissues to support GWAS. Furthermore, maize ( L.) homologs of identified TGW candidates were differentially expressed within the seed between small- and large-kernel lines from a segregating maize population.
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Schmid J, Magee PT, Holland BR, Zhang N, Cannon RD, Magee BB. Last hope for the doomed? Thoughts on the importance of a parasexual cycle for the yeast Candida albicans. Curr Genet 2015; 62:81-5. [DOI: 10.1007/s00294-015-0516-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 12/16/2022]
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