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Perini L, Sipes K, Zervas A, Bellas C, Lutz S, Moniruzzaman M, Mourot R, Benning LG, Tranter M, Anesio AM. Giant viral signatures on the Greenland ice sheet. MICROBIOME 2024; 12:91. [PMID: 38760842 PMCID: PMC11100222 DOI: 10.1186/s40168-024-01796-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/18/2024] [Indexed: 05/19/2024]
Abstract
BACKGROUND Dark pigmented snow and glacier ice algae on glaciers and ice sheets contribute to accelerating melt. The biological controls on these algae, particularly the role of viruses, remain poorly understood. Giant viruses, classified under the nucleocytoplasmic large DNA viruses (NCLDV) supergroup (phylum Nucleocytoviricota), are diverse and globally distributed. NCLDVs are known to infect eukaryotic cells in marine and freshwater environments, providing a biological control on the algal population in these ecosystems. However, there is very limited information on the diversity and ecosystem function of NCLDVs in terrestrial icy habitats. RESULTS In this study, we investigate for the first time giant viruses and their host connections on ice and snow habitats, such as cryoconite, dark ice, ice core, red and green snow, and genomic assemblies of five cultivated Chlorophyta snow algae. Giant virus marker genes were present in almost all samples; the highest abundances were recovered from red snow and the snow algae genomic assemblies, followed by green snow and dark ice. The variety of active algae and protists in these GrIS habitats containing NCLDV marker genes suggests that infection can occur on a range of eukaryotic hosts. Metagenomic data from red and green snow contained evidence of giant virus metagenome-assembled genomes from the orders Imitervirales, Asfuvirales, and Algavirales. CONCLUSION Our study highlights NCLDV family signatures in snow and ice samples from the Greenland ice sheet. Giant virus metagenome-assembled genomes (GVMAGs) were found in red snow samples, and related NCLDV marker genes were identified for the first time in snow algal culture genomic assemblies; implying a relationship between the NCLDVs and snow algae. Metatranscriptomic viral genes also aligned with metagenomic sequences, suggesting that NCLDVs are an active component of the microbial community and are potential "top-down" controls of the eukaryotic algal and protistan members. This study reveals the unprecedented presence of a diverse community of NCLDVs in a variety of glacial habitats dominated by algae.
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Affiliation(s)
- Laura Perini
- Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark.
| | - Katie Sipes
- Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark
| | - Athanasios Zervas
- Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark
| | | | - Stefanie Lutz
- Department of Agroecology and Environment, Plant-Soil Interactions, Agroscope, Zurich, Switzerland
- German Research Centre for Geosciences, Helmholtz Centre Potsdam, Telegrafenberg, Potsdam, 14473, Germany
| | - Mohammad Moniruzzaman
- Department of Biological Sciences, Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, Coral Gables, FL, USA
| | - Rey Mourot
- German Research Centre for Geosciences, Helmholtz Centre Potsdam, Telegrafenberg, Potsdam, 14473, Germany
- Department of Earth Sciences, Freie Universität Berlin, Berlin, 12249, Germany
| | - Liane G Benning
- German Research Centre for Geosciences, Helmholtz Centre Potsdam, Telegrafenberg, Potsdam, 14473, Germany
- Department of Earth Sciences, Freie Universität Berlin, Berlin, 12249, Germany
| | - Martyn Tranter
- Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark
| | - Alexandre M Anesio
- Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark
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2
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Stephens D, Faghihi Z, Moniruzzaman M. Widespread occurrence and diverse origins of polintoviruses influence lineage-specific genome dynamics in stony corals. Virus Evol 2024; 10:veae039. [PMID: 38808038 PMCID: PMC11131425 DOI: 10.1093/ve/veae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 04/29/2024] [Accepted: 05/12/2024] [Indexed: 05/30/2024] Open
Abstract
Stony corals (Order: Scleractinia) are central to vital marine habitats known as coral reefs. Numerous stressors in the Anthropocene are contributing to the ongoing decline in coral reef health and coverage. While viruses are established modulators of marine microbial dynamics, their interactions within the coral holobiont and impact on coral health and physiology remain unclear. To address this key knowledge gap, we investigated diverse stony coral genomes for 'endogenous' viruses. Our study uncovered a remarkable number of integrated viral elements recognized as 'Polintoviruses' (Class Polintoviricetes) in thirty Scleractinia genomes; with several species harboring hundreds to thousands of polintoviruses. We reveal massive paralogous expansion of polintoviruses in stony coral genomes, alongside the presence of integrated elements closely related to Polinton-like viruses (PLVs), a group of viruses that exist as free virions. These results suggest multiple integrations of polintoviruses and PLV-relatives, along with paralogous expansions, shaped stony coral genomes. Re-analysis of existing gene expression data reveals all polintovirus structural and non-structural hallmark genes are expressed, providing support for free virion production from polintoviruses. Our results, revealing a significant diversity of polintovirus across the Scleractinia order, open a new research avenue into polintovirus and their possible roles in disease, genomic plasticity, and environmental adaptation in this key group of organisms.
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Affiliation(s)
- Danae Stephens
- Department of Marine Biology and Ecology, The Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149-1031, USA
| | - Zahra Faghihi
- Department of Marine Biology and Ecology, The Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149-1031, USA
| | - Mohammad Moniruzzaman
- Department of Marine Biology and Ecology, The Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149-1031, USA
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3
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Hassan S, Mushtaq M, Ganiee SA, Zaman M, Yaseen A, Shah AJ, Ganai BA. Microbial oases in the ice: A state-of-the-art review on cryoconite holes as diversity hotspots and their scientific connotations. ENVIRONMENTAL RESEARCH 2024; 252:118963. [PMID: 38640991 DOI: 10.1016/j.envres.2024.118963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 04/13/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024]
Abstract
Cryoconite holes, small meltwater pools on the surface of glaciers and ice sheets, represent extremely cold ecosystems teeming with diverse microbial life. Cryoconite holes exhibit greater susceptibility to the impacts of climate change, underlining the imperative nature of investigating microbial communities as an essential module of polar and alpine ecosystem monitoring efforts. Microbes in cryoconite holes play a critical role in nutrient cycling and can produce bioactive compounds, holding promise for industrial and pharmaceutical innovation. Understanding microbial diversity in these delicate ecosystems is essential for effective conservation strategies. Therefore, this review discusses the microbial diversity in these extreme environments, aiming to unveil the complexity of their microbial communities. The current study envisages that cryoconite holes as distinctive ecosystems encompass a multitude of taxonomically diverse and functionally adaptable microorganisms that exhibit a rich microbial diversity and possess intricate ecological functions. By investigating microbial diversity and ecological functions of cryoconite holes, this study aims to contribute valuable insights into the broader field of environmental microbiology and enhance further understanding of these ecosystems. This review seeks to provide a holistic overview regarding the formation, evolution, characterization, and molecular adaptations of cryoconite holes. Furthermore, future research directions and challenges underlining the need for long-term monitoring, and ethical considerations in preserving these pristine environments are also provided. Addressing these challenges and resolutely pursuing future research directions promises to enrich our comprehension of microbial diversity within cryoconite holes, revealing the broader ecological and biogeochemical implications. The inferences derived from the present study will provide researchers, ecologists, and policymakers with a profound understanding of the significance and utility of cryoconite holes in unveiling the microbial diversity and its potential applications.
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Affiliation(s)
- Shahnawaz Hassan
- Department of Environmental Science, University of Kashmir, Srinagar, 190006, India.
| | - Misba Mushtaq
- Centre of Research for Development, University of Kashmir, Srinagar, 190006, India
| | - Shahid Ahmad Ganiee
- Department of Environmental Science, University of Kashmir, Srinagar, 190006, India
| | - Muzafar Zaman
- Department of Environmental Science, University of Kashmir, Srinagar, 190006, India
| | - Aarif Yaseen
- Department of Environmental Science, University of Kashmir, Srinagar, 190006, India
| | - Abdul Jalil Shah
- Department of Pharmaceutical Sciences, University of Kashmir, Srinagar, 190006, India
| | - Bashir Ahmad Ganai
- Centre of Research for Development, University of Kashmir, Srinagar, 190006, India.
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4
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Woudstra C, Sørensen AN, Sørensen MCH, Brøndsted L. Strategies for developing phages into novel antimicrobial tailocins. Trends Microbiol 2024:S0966-842X(24)00069-6. [PMID: 38580606 DOI: 10.1016/j.tim.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 04/07/2024]
Abstract
Tailocins are high-molecular-weight bacteriocins produced by bacteria to kill related environmental competitors by binding and puncturing their target. Tailocins are promising alternative antimicrobials, yet the diversity of naturally occurring tailocins is limited. The structural similarities between phage tails and tailocins advocate using phages as scaffolds for developing new tailocins. This article reviews three strategies for producing tailocins: disrupting the capsid-tail junction of phage particles, blocking capsid assembly during phage propagation, and creating headless phage particles synthetically. Particularly appealing is the production of tailocins through synthetic biology using phages with contractile tails as scaffolds to unlock the antimicrobial potential of tailocins.
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Affiliation(s)
- Cedric Woudstra
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Anders Nørgaard Sørensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Martine C Holst Sørensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Lone Brøndsted
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark.
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5
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Rassner SME, Cook JM, Mitchell AC, Stevens IT, Irvine-Fynn TDL, Hodson AJ, Edwards A. The distinctive weathering crust habitat of a High Arctic glacier comprises discrete microbial micro-habitats. Environ Microbiol 2024; 26:e16617. [PMID: 38558266 DOI: 10.1111/1462-2920.16617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
Sunlight penetrates the ice surfaces of glaciers and ice sheets, forming a water-bearing porous ice matrix known as the weathering crust. This crust is home to a significant microbial community. Despite the potential implications of microbial processes in the weathering crust for glacial melting, biogeochemical cycles, and downstream ecosystems, there have been few explorations of its microbial communities. In our study, we used 16S rRNA gene sequencing and shotgun metagenomics of a Svalbard glacier surface catchment to characterise the microbial communities within the weathering crust, their origins and destinies, and the functional potential of the weathering crust metagenome. Our findings reveal that the bacterial community in the weathering crust is distinct from those in upstream and downstream habitats. However, it comprises two separate micro-habitats, each with different taxa and functional categories. The interstitial porewater is dominated by Polaromonas, influenced by the transfer of snowmelt, and exported via meltwater channels. In contrast, the ice matrix is dominated by Hymenobacter, and its metagenome exhibits a diverse range of functional adaptations. Given that the global weathering crust area and the subsequent release of microbes from it are strongly responsive to climate projections for the rest of the century, our results underscore the pressing need to integrate the microbiome of the weathering crust with other communities and processes in glacial ecosystems.
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Affiliation(s)
| | - Joseph M Cook
- Department of Life Sciences, Aberystwyth University, Wales, UK
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Andrew C Mitchell
- Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
| | - Ian T Stevens
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
| | | | - Andrew J Hodson
- Department of Arctic Geology, University Centre in Svalbard (UNIS), Longyearbyen, Norway
| | - Arwyn Edwards
- Department of Life Sciences, Aberystwyth University, Wales, UK
- Department of Arctic Biology, University Centre in Svalbard (UNIS), Longyearbyen, Norway
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6
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Wang Y, Xu N, Chen B, Zhang Z, Lei C, Zhang Q, Gu Y, Wang T, Wang M, Penuelas J, Qian H. Metagenomic analysis of antibiotic-resistance genes and viruses released from glaciers into downstream habitats. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168310. [PMID: 37944612 DOI: 10.1016/j.scitotenv.2023.168310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023]
Abstract
Glaciers serve as effective reservoirs of antibiotic resistance genes (ARGs) and viruses for millions of years. Climate change and anthropogenic activity have accelerated the melting of glaciers, but the patterns of release of ARGs and viruses from melting glaciers into downstream habitats remain unknown. We analyzed 171 metagenomic samples from glaciers and their downstream habitats and found that the abundance and diversity of ARGs were higher in glaciers (polar and plateau glaciers) than downstream habitats (Arctic Ocean, Qinghai Lake, and Yangtze River Basin), with the diversity of viruses having the opposite pattern. Proteobacteria and Actinobacteria were the main potential hosts of ARGs and viruses, and the richness of ARGs carried by the hosts was positively correlated with viral abundance, suggesting that the transmission of viruses in the hosts could disseminate ARGs. Source tracking indicated that >18 % of the ARGs and >25 % of the viruses detected in downstream habitats originated from glaciers, demonstrating that glaciers could be one of the potential sources of ARGs and viruses in downstream habitats. Increased solar radiation and emission of carbon dioxide mainly influenced the release of the ARGs and viruses from glaciers into downstream habitats. This study provides a systematic insight demonstrating the release of ARGs and viruses from the melting glaciers, potentially increasing ecological pressure.
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Affiliation(s)
- Yan Wang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Nuohan Xu
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Bingfeng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Chaotang Lei
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Qi Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Yanpeng Gu
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Tingzhang Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou 310012, PR China
| | - Meixia Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou 310012, PR China
| | - Josep Penuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona 08193, Catalonia, Spain; CREAF, Campus Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona 08193, Catalonia, Spain
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China.
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7
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Li J, Wu S, Zhang K, Sun X, Lin W, Wang C, Lin S. Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR-Associated Protein and Its Utility All at Sea: Status, Challenges, and Prospects. Microorganisms 2024; 12:118. [PMID: 38257946 PMCID: PMC10820777 DOI: 10.3390/microorganisms12010118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/02/2024] [Accepted: 01/04/2024] [Indexed: 01/24/2024] Open
Abstract
Initially discovered over 35 years ago in the bacterium Escherichia coli as a defense system against invasion of viral (or other exogenous) DNA into the genome, CRISPR/Cas has ushered in a new era of functional genetics and served as a versatile genetic tool in all branches of life science. CRISPR/Cas has revolutionized the methodology of gene knockout with simplicity and rapidity, but it is also powerful for gene knock-in and gene modification. In the field of marine biology and ecology, this tool has been instrumental in the functional characterization of 'dark' genes and the documentation of the functional differentiation of gene paralogs. Powerful as it is, challenges exist that have hindered the advances in functional genetics in some important lineages. This review examines the status of applications of CRISPR/Cas in marine research and assesses the prospect of quickly expanding the deployment of this powerful tool to address the myriad fundamental marine biology and biological oceanography questions.
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Affiliation(s)
- Jiashun Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
| | - Shuaishuai Wu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
| | - Kaidian Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Marine Biology and Fisheries, Hainan University, Haikou 570203, China
| | - Xueqiong Sun
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
| | - Wenwen Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
| | - Cong Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361101, China
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA
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8
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Liu Y, Jiao N, Xu Zhong K, Zang L, Zhang R, Xiao X, Shi Y, Zhang Z, Tao Y, Bai L, Gao B, Yang Y, Huang X, Ji M, Liu J, Liu P, Yao T. Diversity and function of mountain and polar supraglacial DNA viruses. Sci Bull (Beijing) 2023; 68:2418-2433. [PMID: 37739838 DOI: 10.1016/j.scib.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/29/2023] [Accepted: 06/30/2023] [Indexed: 09/24/2023]
Abstract
Mountain and polar glaciers cover 10% of the Earth's surface and are typically extreme environments that challenge life of all forms. Viruses are abundant and active in supraglacial ecosystems and play a crucial role in controlling the supraglacial microbial communities. However, our understanding of virus ecology on glacier surfaces and their potential impacts on downstream ecosystems remains limited. Here, we present the supraglacial virus genome (SgVG) catalog, a 15-fold expanded genomic inventory of 10,840 DNA-virus species from 38 mountain and polar glaciers, spanning habitats such as snow, ice, meltwater, and cryoconite. Supraglacial DNA-viruses were highly specific compared to viruses in other ecosystems yet exhibited low public health risks. Supraglacial viral communities were primarily constrained by habitat, with cryoconite displaying the highest viral activity levels. We observed a prevalence of lytic viruses in all habitats, especially in cryoconite, but a high level of lysogenic viruses in snow and ice. Additionally, we found that supraglacial viruses could be linked to ∼83% of obtained prokaryotic phyla/classes and possessed the genetic potential to promote metabolism and increase cold adaptation, cell mobility, and phenolic carbon use of hosts in hostile environmental conditions using diverse auxiliary metabolic genes. Our results provide the first systematic characterization of the diversity, function, and public health risks evaluation of mountain and polar supraglacial DNA viruses. This understanding of glacial viruses is crucial for function assessments and ecological modeling of glacier ecosystems, especially for the Tibetan Plateau's Mountain glaciers, which support ∼20% of the human populations on Earth.
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Affiliation(s)
- Yongqin Liu
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China; State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China.
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Kevin Xu Zhong
- Department of Earth, Ocean, and Atmospheric Sciences, The University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Lin Zang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China
| | - Rui Zhang
- Institute for Advanced Study, Shenzhen University, Shenzhen 518000, China
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yi Shi
- University of Chinese Academy of Sciences, Beijing 100101, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhihao Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China
| | - Ye Tao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Liping Bai
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China
| | - Bianli Gao
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China
| | - Yunlan Yang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Xingyu Huang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Mukan Ji
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China
| | - Junzhi Liu
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China
| | - Pengfei Liu
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China.
| | - Tandong Yao
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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Zhang W, Wang R, Zou X, Gu C, Yang Q, He M, Xiao W, He L, Zhao M, Yu Z. Comparative genomic analysis of alloherpesviruses: Exploring an available genus/species demarcation proposal and method. Virus Res 2023; 334:199163. [PMID: 37364814 PMCID: PMC10410580 DOI: 10.1016/j.virusres.2023.199163] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
The family Alloherpesviridae contains herpesviruses of fish and amphibians. Due to the significant economic losses to aquaculture that herpesviruses can cause, the primary areas of research interest are concerning their pathogenesis and prevention. Despite alloherpesvirus genomic sequences becoming more widely accessible, methods regarding their genus/species classification are still relatively unexplored. In the present study, the phylogenetic relationships between 40 completely sequenced alloherpesviruses were illustrated by the viral proteomic tree (ViPTree), which was divided into three monophyletic groups, namely Cyprinivirus, Ictalurivirus and Batrachovirus. Additionally, average nucleotide identity (ANI) and average amino acid identity (AAI) analyses were performed across all available sequences and clearly displayed species boundaries with the threshold value of ANI/AAI set at 90%. Subsequently, core-pan analysis uncovered 809 orthogroups and 11 core genes shared by all 40 alloherpesvirus genome sequences. For the former, a 15 percent identity depicts a clear genus boundary; for the latter, 8 of them may be qualified for phylogenetic analysis based on amino acid or nucleic acid sequences after being verified using maximum likelihood (ML) or neighbor-joining (NJ) phylogenetic trees. Finally, although the dot plot analysis was valid for the members within Ictalurivirus, it was unsuccessful for Cyprinivirus and Batrachovirus. Taken together, the comparison of individual methodologies provides a wide range of alternatives for alloherpesviruses classification under various circumstances.
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Affiliation(s)
- Wenjie Zhang
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China
| | - Ran Wang
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China
| | - Xiaoxia Zou
- Suining First People's Hospital, Suining, PR China
| | - Congwei Gu
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Qian Yang
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Manli He
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Wudian Xiao
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Lvqin He
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Mingde Zhao
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China
| | - Zehui Yu
- Laboratory Animal Center, Southwest Medical University, Luzhou Sichuan, PR China; Model Animal and Human Disease Research of Luzhou Key Laboratory, PR China; Scholl of Basic Medical Sciences, Zhejiang University, Hangzhou, PR China.
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10
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Zhong ZP, Vik D, Rapp JZ, Zablocki O, Maughan H, Temperton B, Deming JW, Sullivan MB. Lower viral evolutionary pressure under stable versus fluctuating conditions in subzero Arctic brines. MICROBIOME 2023; 11:174. [PMID: 37550784 PMCID: PMC10405475 DOI: 10.1186/s40168-023-01619-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/12/2023] [Indexed: 08/09/2023]
Abstract
BACKGROUND Climate change threatens Earth's ice-based ecosystems which currently offer archives and eco-evolutionary experiments in the extreme. Arctic cryopeg brine (marine-derived, within permafrost) and sea ice brine, similar in subzero temperature and high salinity but different in temporal stability, are inhabited by microbes adapted to these extreme conditions. However, little is known about their viruses (community composition, diversity, interaction with hosts, or evolution) or how they might respond to geologically stable cryopeg versus fluctuating sea ice conditions. RESULTS We used long- and short-read viromics and metatranscriptomics to study viruses in Arctic cryopeg brine, sea ice brine, and underlying seawater, recovering 11,088 vOTUs (~species-level taxonomic unit), a 4.4-fold increase of known viruses in these brines. More specifically, the long-read-powered viromes doubled the number of longer (≥25 kb) vOTUs generated and recovered more hypervariable regions by >5-fold compared to short-read viromes. Distribution assessment, by comparing to known viruses in public databases, supported that cryopeg brine viruses were of marine origin yet distinct from either sea ice brine or seawater viruses, while 94% of sea ice brine viruses were also present in seawater. A virus-encoded, ecologically important exopolysaccharide biosynthesis gene was identified, and many viruses (~half of metatranscriptome-inferred "active" vOTUs) were predicted as actively infecting the dominant microbial genera Marinobacter and Polaribacter in cryopeg and sea ice brines, respectively. Evolutionarily, microdiversity (intra-species genetic variations) analyses suggested that viruses within the stable cryopeg brine were under significantly lower evolutionary pressures than those in the fluctuating sea ice environment, while many sea ice brine virus-tail genes were under positive selection, indicating virus-host co-evolutionary arms races. CONCLUSIONS Our results confirmed the benefits of long-read-powered viromics in understanding the environmental virosphere through significantly improved genomic recovery, expanding viral discovery and the potential for biological inference. Evidence of viruses actively infecting the dominant microbes in subzero brines and modulating host metabolism underscored the potential impact of viruses on these remote and underexplored extreme ecosystems. Microdiversity results shed light on different strategies viruses use to evolve and adapt when extreme conditions are stable versus fluctuating. Together, these findings verify the value of long-read-powered viromics and provide foundational data on viral evolution and virus-microbe interactions in Earth's destabilized and rapidly disappearing cryosphere. Video Abstract.
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Affiliation(s)
- Zhi-Ping Zhong
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Dean Vik
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Josephine Z Rapp
- Department of Biology, Université Laval, Québec, QC, Canada
- Center for Northern Studies (CEN), Université Laval, Québec, QC, Canada
| | - Olivier Zablocki
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | | | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, Devon, UK
| | - Jody W Deming
- School of Oceanography and Astrobiology Program, University of Washington, Seattle, WA, USA.
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA.
- Department of Microbiology, Ohio State University, Columbus, OH, USA.
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA.
- Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, USA.
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11
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Past and present giant viruses diversity explored through permafrost metagenomics. Nat Commun 2022; 13:5853. [PMID: 36207343 PMCID: PMC9546926 DOI: 10.1038/s41467-022-33633-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022] Open
Abstract
Giant viruses are abundant in aquatic environments and ecologically important through the metabolic reprogramming of their hosts. Less is known about giant viruses from soil even though two of them, belonging to two different viral families, were reactivated from 30,000-y-old permafrost samples. This suggests an untapped diversity of Nucleocytoviricota in this environment. Through permafrost metagenomics we reveal a unique diversity pattern and a high heterogeneity in the abundance of giant viruses, representing up to 12% of the sum of sequence coverage in one sample. Pithoviridae and Orpheoviridae-like viruses were the most important contributors. A complete 1.6 Mb Pithoviridae-like circular genome was also assembled from a 42,000-y-old sample. The annotation of the permafrost viral sequences revealed a patchwork of predicted functions amidst a larger reservoir of genes of unknown functions. Finally, the phylogenetic reconstructions not only revealed gene transfers between cells and viruses, but also between viruses from different families. Although giant viruses are abundant in aquatic environments, less is known about giant viruses in soil. Here, the authors use permafrost metagenomics to reveal giant virus diversity and heterogeneity, as well as gene transfers between viruses from different families.
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12
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Doting EL, Davie-Martin CL, Johansen A, Benning LG, Tranter M, Rinnan R, Anesio AM. Greenland Ice Sheet Surfaces Colonized by Microbial Communities Emit Volatile Organic Compounds. Front Microbiol 2022; 13:886293. [PMID: 35747370 PMCID: PMC9211068 DOI: 10.3389/fmicb.2022.886293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Volatile organic compounds (VOCs) are emitted by organisms for a range of physiological and ecological reasons. They play an important role in biosphere–atmosphere interactions and contribute to the formation of atmospheric secondary aerosols. The Greenland ice sheet is home to a variety of microbial communities, including highly abundant glacier ice algae, yet nothing is known about the VOCs emitted by glacial communities. For the first time, we present VOC emissions from supraglacial habitats colonized by active microbial communities on the southern Greenland ice sheet during July 2020. Emissions of C5–C30 compounds from bare ice, cryoconite holes, and red snow were collected using a push–pull chamber active sampling system. A total of 92 compounds were detected, yielding mean total VOC emission rates of 3.97 ± 0.70 μg m–2 h–1 from bare ice surfaces (n = 31), 1.63 ± 0.13 μg m–2 h–1 from cryoconite holes (n = 4), and 0.92 ± 0.08 μg m–2 h–1 from red snow (n = 2). No correlations were found between VOC emissions and ice surface algal counts, but a weak positive correlation (r = 0.43, p = 0.015, n = 31) between VOC emission rates from bare ice surfaces and incoming shortwave radiation was found. We propose that this may be due to the stress that high solar irradiance causes in bare ice microbial communities. Acetophenone, benzaldehyde, and phenylmaleic anhydride, all of which have reported antifungal activity, accounted for 51.1 ± 11.7% of emissions from bare ice surfaces, indicating a potential defense strategy against fungal infections. Greenland ice sheet microbial habitats are, hence, potential sources of VOCs that may play a role in supraglacial microbial interactions, as well as local atmospheric chemistry, and merit future research efforts.
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Affiliation(s)
- Eva L. Doting
- Department of Environmental Science, iClimate, Aarhus University, Roskilde, Denmark
- *Correspondence: Eva L. Doting,
| | - Cleo L. Davie-Martin
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anders Johansen
- Department of Environmental Science, iClimate, Aarhus University, Roskilde, Denmark
| | - Liane G. Benning
- Interface Geochemistry, German Research Centre for Geosciences, GFZ Potsdam, Potsdam, Germany
- Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
| | - Martyn Tranter
- Department of Environmental Science, iClimate, Aarhus University, Roskilde, Denmark
| | - Riikka Rinnan
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Alexandre M. Anesio
- Department of Environmental Science, iClimate, Aarhus University, Roskilde, Denmark
- Alexandre M. Anesio,
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13
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Winkel M, Trivedi CB, Mourot R, Bradley JA, Vieth-Hillebrand A, Benning LG. Seasonality of Glacial Snow and Ice Microbial Communities. Front Microbiol 2022; 13:876848. [PMID: 35651494 PMCID: PMC9149292 DOI: 10.3389/fmicb.2022.876848] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/26/2022] [Indexed: 01/03/2023] Open
Abstract
Blooms of microalgae on glaciers and ice sheets are amplifying surface ice melting rates, which are already affected by climate change. Most studies on glacial microorganisms (including snow and glacier ice algae) have so far focused on the spring and summer melt season, leading to a temporal bias, and a knowledge gap in our understanding of the variations in microbial diversity, productivity, and physiology on glacier surfaces year-round. Here, we investigated the microbial communities from Icelandic glacier surface snow and bare ice habitats, with sampling spanning two consecutive years and carried out in both winter and two summer seasons. We evaluated the seasonal differences in microbial community composition using Illumina sequencing of the 16S rRNA, 18S rRNA, and ITS marker genes and correlating them with geochemical signals in the snow and ice. During summer, Chloromonas, Chlainomonas, Raphidonema, and Hydrurus dominated surface snow algal communities, while Ancylonema and Mesotaenium dominated the surface bare ice habitats. In winter, algae could not be detected, and the community composition was dominated by bacteria and fungi. The dominant bacterial taxa found in both winter and summer samples were Bacteriodetes, Actinobacteria, Alphaproteobacteria, and Gammaproteobacteria. The winter bacterial communities showed high similarities to airborne and fresh snow bacteria reported in other studies. This points toward the importance of dry and wet deposition as a wintertime source of microorganisms to the glacier surface. Winter samples were also richer in nutrients than summer samples, except for dissolved organic carbon-which was highest in summer snow and ice samples with blooming microalgae, suggesting that nutrients are accumulated during winter but primarily used by the microbial communities in the summer. Overall, our study shows that glacial snow and ice microbial communities are highly variable on a seasonal basis.
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Affiliation(s)
- Matthias Winkel
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany
| | - Christopher B Trivedi
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany
| | - Rey Mourot
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany
| | - James A Bradley
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany.,School of Geography, Queen Mary University of London, London, United Kingdom
| | - Andrea Vieth-Hillebrand
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany
| | - Liane G Benning
- GFZ German Research Centre for Geosciences, Helmholtz Centre for Geosciences, Potsdam, Germany.,Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
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14
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Perini L, Gostinčar C, Likar M, Frisvad JC, Kostanjšek R, Nicholes M, Williamson C, Anesio AM, Zalar P, Gunde-Cimerman N. Interactions of Fungi and Algae from the Greenland Ice Sheet. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02033-5. [PMID: 35608637 DOI: 10.1007/s00248-022-02033-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
Heavily pigmented glacier ice algae Ancylonema nordenskiöldii and Ancylonema alaskanum (Zygnematophyceae, Streptophyta) reduce the bare ice albedo of the Greenland Ice Sheet, amplifying melt from the largest cryospheric contributor to eustatic sea-level rise. Little information is available about glacier ice algae interactions with other microbial communities within the surface ice environment, including fungi, which may be important for sustaining algal bloom development. To address this substantial knowledge gap and investigate the nature of algal-fungal interactions, an ex situ co-cultivation experiment with two species of fungi, recently isolated from the surface of the Greenland Ice Sheet (here proposed new species Penicillium anthracinoglaciei Perini, Frisvad and Zalar, Mycobank (MB 835602), and Articulospora sp.), and the mixed microbial community dominated by glacier ice algae was performed. The utilization of the dark pigment purpurogallin carboxylic acid-6-O-β-D-glucopyranoside (C18H18O12) by the two fungi was also evaluated in a separate experiment. P. anthracinoglaciei was capable of utilizing and converting the pigment to purpurogallin carboxylic acid, possibly using the sugar moiety as a nutrient source. Furthermore, after 3 weeks of incubation in the presence of P. anthracinoglaciei, a significantly slower decline in the maximum quantum efficiency (Fv/Fm, inverse proxy of algal stress) in glacier ice algae, compared to other treatments, was evident, suggesting a positive relationship between these species. Articulospora sp. did uptake the glycosylated purpurogallin, but did not seem to be involved in its conversion to aglycone derivative. At the end of the incubation experiments and, in conjunction with increased algal mortality, we detected a substantially increasing presence of the zoosporic fungi Chytridiomycota suggesting an important role for them as decomposers or parasites of glacier ice algae.
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Affiliation(s)
- L Perini
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.
- Department of Environmental Science, Aarhus University, 4000, Roskilde, Denmark.
| | - C Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
- Lars Bolund Institute of Regenerative Medicine, BGI-Qingdao, Qingdao, 266555, China
| | - M Likar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - J C Frisvad
- Department of Biotechnology and Biomedicine, Fungal Chemodiversity, Technical University of Denmark, Søltofts Plads, Building 221, 2800, Kgs. Lyngby, Denmark
| | - R Kostanjšek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - M Nicholes
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - C Williamson
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - A M Anesio
- Department of Environmental Science, Aarhus University, 4000, Roskilde, Denmark
| | - P Zalar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - N Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
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15
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Alternative functions of CRISPR-Cas systems in the evolutionary arms race. Nat Rev Microbiol 2022; 20:351-364. [PMID: 34992260 DOI: 10.1038/s41579-021-00663-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 12/14/2022]
Abstract
CRISPR-Cas systems of bacteria and archaea comprise chromosomal loci with typical repetitive clusters and associated genes encoding a range of Cas proteins. Adaptation of CRISPR arrays occurs when virus-derived and plasmid-derived sequences are integrated as new CRISPR spacers. Cas proteins use CRISPR-derived RNA guides to specifically recognize and cleave nucleic acids of invading mobile genetic elements. Apart from this role as an adaptive immune system, some CRISPR-associated nucleases are hijacked by mobile genetic elements: viruses use them to attack their prokaryotic hosts, and transposons have adopted CRISPR systems for guided transposition. In addition, some CRISPR-Cas systems control the expression of genes involved in bacterial physiology and virulence. Moreover, pathogenic bacteria may use their Cas nuclease activity indirectly to evade the human immune system or directly to invade the nucleus and damage the chromosomal DNA of infected human cells. Thus, the evolutionary arms race has led to the expansion of exciting variations in CRISPR mechanisms and functionalities. In this Review, we explore the latest insights into the diverse functions of CRISPR-Cas systems beyond adaptive immunity and discuss the implications for the development of CRISPR-based applications.
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16
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Zhong ZP, Tian F, Roux S, Gazitúa MC, Solonenko NE, Li YF, Davis ME, Van Etten JL, Mosley-Thompson E, Rich VI, Sullivan MB, Thompson LG. Glacier ice archives nearly 15,000-year-old microbes and phages. MICROBIOME 2021; 9:160. [PMID: 34281625 PMCID: PMC8290583 DOI: 10.1186/s40168-021-01106-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/31/2021] [Indexed: 05/05/2023]
Abstract
BACKGROUND Glacier ice archives information, including microbiology, that helps reveal paleoclimate histories and predict future climate change. Though glacier-ice microbes are studied using culture or amplicon approaches, more challenging metagenomic approaches, which provide access to functional, genome-resolved information and viruses, are under-utilized, partly due to low biomass and potential contamination. RESULTS We expand existing clean sampling procedures using controlled artificial ice-core experiments and adapted previously established low-biomass metagenomic approaches to study glacier-ice viruses. Controlled sampling experiments drastically reduced mock contaminants including bacteria, viruses, and free DNA to background levels. Amplicon sequencing from eight depths of two Tibetan Plateau ice cores revealed common glacier-ice lineages including Janthinobacterium, Polaromonas, Herminiimonas, Flavobacterium, Sphingomonas, and Methylobacterium as the dominant genera, while microbial communities were significantly different between two ice cores, associating with different climate conditions during deposition. Separately, ~355- and ~14,400-year-old ice were subject to viral enrichment and low-input quantitative sequencing, yielding genomic sequences for 33 vOTUs. These were virtually all unique to this study, representing 28 novel genera and not a single species shared with 225 environmentally diverse viromes. Further, 42.4% of the vOTUs were identifiable temperate, which is significantly higher than that in gut, soil, and marine viromes, and indicates that temperate phages are possibly favored in glacier-ice environments before being frozen. In silico host predictions linked 18 vOTUs to co-occurring abundant bacteria (Methylobacterium, Sphingomonas, and Janthinobacterium), indicating that these phages infected ice-abundant bacterial groups before being archived. Functional genome annotation revealed four virus-encoded auxiliary metabolic genes, particularly two motility genes suggest viruses potentially facilitate nutrient acquisition for their hosts. Finally, given their possible importance to methane cycling in ice, we focused on Methylobacterium viruses by contextualizing our ice-observed viruses against 123 viromes and prophages extracted from 131 Methylobacterium genomes, revealing that the archived viruses might originate from soil or plants. CONCLUSIONS Together, these efforts further microbial and viral sampling procedures for glacier ice and provide a first window into viral communities and functions in ancient glacier environments. Such methods and datasets can potentially enable researchers to contextualize new discoveries and begin to incorporate glacier-ice microbes and their viruses relative to past and present climate change in geographically diverse regions globally. Video Abstract.
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Affiliation(s)
- Zhi-Ping Zhong
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Funing Tian
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Simon Roux
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Natalie E Solonenko
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Yueh-Fen Li
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Mary E Davis
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Ellen Mosley-Thompson
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
- Department of Geography, Ohio State University, Columbus, OH, USA
| | - Virginia I Rich
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA.
- Department of Microbiology, Ohio State University, Columbus, OH, USA.
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA.
- Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, USA.
| | - Lonnie G Thompson
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA.
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA.
- School of Earth Sciences, Ohio State University, Columbus, OH, USA.
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17
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Yarzábal LA, Salazar LMB, Batista-García RA. Climate change, melting cryosphere and frozen pathogens: Should we worry…? ENVIRONMENTAL SUSTAINABILITY (SINGAPORE) 2021; 4:489-501. [PMID: 38624658 PMCID: PMC8164958 DOI: 10.1007/s42398-021-00184-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 05/12/2021] [Accepted: 05/15/2021] [Indexed: 11/21/2022]
Abstract
Permanently frozen environments (glaciers, permafrost) are considered as natural reservoirs of huge amounts of microorganisms, mostly dormant, including human pathogens. Due to global warming, which increases the rate of ice-melting, approximately 4 × 1021 of these microorganisms are released annually from their frozen confinement and enter natural ecosystems, in close proximity to human settlements. Some years ago, the hypothesis was put forward that this massive release of potentially-pathogenic microbes-many of which disappeared from the face of the Earth thousands and even millions of years ago-could give rise to epidemics. The recent anthrax outbreaks that occurred in Siberia, and the presence of bacterial and viral pathogens in glaciers worldwide, seem to confirm this hypothesis. In that context, the present review summarizes the currently available scientific evidence that allows us to imagine a near future in which epidemic outbreaks, similar to the abovementioned, could occur as a consequence of the resurrection and release of microbes from glaciers and permafrost. Supplementary Information The online version of this article (10.1007/s42398-021-00184-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luis Andrés Yarzábal
- Unidad de Salud y Bienestar, Universidad Católica de Cuenca, Av. Las Américas and Calle Humboldt, Cuenca, Ecuador
- Centro de Investigación, Innovación y Transferencia de Tecnología (CIITT), Universidad Católica de Cuenca, Campus Miracielos, Ricaurte, Ecuador
| | - Lenys M. Buela Salazar
- Unidad de Salud y Bienestar, Universidad Católica de Cuenca, Av. Las Américas and Calle Humboldt, Cuenca, Ecuador
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos Mexico
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18
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Qian H, Zhang Q, Lu T, Peijnenburg WJGM, Penuelas J, Zhu YG. Lessons learned from COVID-19 on potentially pathogenic soil microorganisms. SOIL ECOLOGY LETTERS 2021. [PMCID: PMC7661327 DOI: 10.1007/s42832-020-0068-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032 China
| | - Qi Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032 China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032 China
| | - W. J. G. M. Peijnenburg
- Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, The Netherlands
- Center for Safety of Substances and Products, National Institute of Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, The Netherlands
| | - Josep Penuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia Spain
- CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia Spain
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 China
- University of the Chinese Academy of Sciences, Beijing, 100049 China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China
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19
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Sajjad W, Rafiq M, Din G, Hasan F, Iqbal A, Zada S, Ali B, Hayat M, Irfan M, Kang S. Resurrection of inactive microbes and resistome present in the natural frozen world: Reality or myth? THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 735:139275. [PMID: 32480145 DOI: 10.1016/j.scitotenv.2020.139275] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
The present world faces a new threat of ancient microbes and resistomes that are locked in the cryosphere and now releasing upon thawing due to climate change and anthropogenic activities. The cryosphere act as the best preserving place for these microbes and resistomes that stay alive for millions of years. Current reviews extensively discussed whether the resurrection of microbes and resistomes existing in these pristine environments is true or just a hype. Release of these ancient microorganisms and naked DNA is of great concern for society as these microbes can either cause infections directly or they can interact with contemporary microorganisms and affect their fitness, survival, and mutation rate. Moreover, the contemporary microorganisms may uptake the unlocked naked DNA, which might transform non-pathogenic microorganisms into deadly antibiotic-resistant microbes. Additionally, the resurrection of glacial microorganisms can cause adverse effects on ecosystems downstream. The release of glacial pathogens and naked DNA is real and can lead to fatal outbreaks; therefore, we must prepare ourselves for the possible reemergence of diseases caused by these microbes. This study provides a scientific base for the adoption of actions by international cooperation to develop preventive measures.
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Affiliation(s)
- Wasim Sajjad
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Muhammad Rafiq
- Department of Microbiology, Faculty of Life Sciences and Informatics, Balochistan University of IT, Engineering and Management Sciences, Quetta, Pakistan
| | - Ghufranud Din
- Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Fariha Hasan
- Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Awais Iqbal
- School of Life Sciences, State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, Lanzhou, China
| | - Sahib Zada
- Department of Biology, College of Science, Shantou University, Shantou, China
| | - Barkat Ali
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Muhammad Hayat
- Institute of Microbial Technology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao Campus, China
| | - Muhammad Irfan
- College of Dentistry, Department of Oral Biology, University of Florida, Gainesville, FL. USA
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China.
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20
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Federici S, Nobs SP, Elinav E. Phages and their potential to modulate the microbiome and immunity. Cell Mol Immunol 2020; 18:889-904. [PMID: 32901128 DOI: 10.1038/s41423-020-00532-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023] Open
Abstract
Bacteriophages (hence termed phages) are viruses that target bacteria and have long been considered as potential future treatments against antibiotic-resistant bacterial infection. However, the molecular nature of phage interactions with bacteria and the human host has remained elusive for decades, limiting their therapeutic application. While many phages and their functional repertoires remain unknown, the advent of next-generation sequencing has increasingly enabled researchers to decode new lytic and lysogenic mechanisms by which they attack and destroy bacteria. Furthermore, the last decade has witnessed a renewed interest in the utilization of phages as therapeutic vectors and as a means of targeting pathogenic or commensal bacteria or inducing immunomodulation. Importantly, the narrow host range, immense antibacterial repertoire, and ease of manipulating phages may potentially allow for their use as targeted modulators of pathogenic, commensal and pathobiont members of the microbiome, thereby impacting mammalian physiology and immunity along mucosal surfaces in health and in microbiome-associated diseases. In this review, we aim to highlight recent advances in phage biology and how a mechanistic understanding of phage-bacteria-host interactions may facilitate the development of novel phage-based therapeutics. We provide an overview of the challenges of the therapeutic use of phages and how these could be addressed for future use of phages as specific modulators of the human microbiome in a variety of infectious and noncommunicable human diseases.
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Affiliation(s)
- Sara Federici
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Samuel P Nobs
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel. .,Cancer-Microbiome Division Deutsches Krebsforschungszentrum (DKFZ), Neuenheimer Feld 280, 69120, Heidelberg, Germany.
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21
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Bellas CM, Schroeder DC, Edwards A, Barker G, Anesio AM. Flexible genes establish widespread bacteriophage pan-genomes in cryoconite hole ecosystems. Nat Commun 2020; 11:4403. [PMID: 32879312 PMCID: PMC7468147 DOI: 10.1038/s41467-020-18236-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022] Open
Abstract
Bacteriophage genomes rapidly evolve via mutation and horizontal gene transfer to counter evolving bacterial host defenses; such arms race dynamics should lead to divergence between phages from similar, geographically isolated ecosystems. However, near-identical phage genomes can reoccur over large geographical distances and several years apart, conversely suggesting many are stably maintained. Here, we show that phages with near-identical core genomes in distant, discrete aquatic ecosystems maintain diversity by possession of numerous flexible gene modules, where homologous genes present in the pan-genome interchange to create new phage variants. By repeatedly reconstructing the core and flexible regions of phage genomes from different metagenomes, we show a pool of homologous gene variants co-exist for each module in each location, however, the dominant variant shuffles independently in each module. These results suggest that in a natural community, recombination is the largest contributor to phage diversity, allowing a variety of host recognition receptors and genes to counter bacterial defenses to co-exist for each phage. Bacteriophages and their hosts are involved in a constant evolutionary arms race that should lead to divergence between phage genes over time. Here, the authors recruit metagenomic reads to virus reference genomes and genome fragments in samples from cryoconite holes and show that phages with near-identical core genomes maintain diversity by possession of numerous flexible gene modules, where homologous genes present in the pan-genome interchange to create new phage variants.
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Affiliation(s)
- Christopher M Bellas
- Department of Ecology, Lake and Glacier Ecology, University of Innsbruck, Technikerstrasse 25, 6020, Innsbruck, Austria.
| | - Declan C Schroeder
- Department of Veterinary Population Medicine, University of Minnesota, 1333 Gortner Avenue, St. Paul, MN, 55108, USA.,School of Biological Sciences, University of Reading, Reading, UK
| | - Arwyn Edwards
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3EE, UK
| | - Gary Barker
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Alexandre M Anesio
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark
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22
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Tsiola A, Michoud G, Fodelianakis S, Karakassis I, Kotoulas G, Pavlidou A, Pavloudi C, Pitta P, Simboura N, Daffonchio D, Tsapakis M. Viral Metagenomic Content Reflects Seawater Ecological Quality in the Coastal Zone. Viruses 2020; 12:v12080806. [PMID: 32722579 PMCID: PMC7472104 DOI: 10.3390/v12080806] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 01/21/2023] Open
Abstract
Viruses interfere with their host’s metabolism through the expression of auxiliary metabolic genes (AMGs) that, until now, are mostly studied under large physicochemical gradients. Here, we focus on coastal marine ecosystems and we sequence the viral metagenome (virome) of samples with discrete levels of human-driven disturbances. We aim to describe the relevance of viromics with respect to ecological quality status, defined by the classic seawater trophic index (TRIX). Neither viral (family level) nor bacterial (family level, based on 16S rRNA sequencing) community structure correlated with TRIX. AMGs involved in the Calvin and tricarboxylic acid cycles were found at stations with poor ecological quality, supporting viral lysis by modifying the host’s energy supply. AMGs involved in “non-traditional” energy-production pathways (3HP, sulfur oxidation) were found irrespective of ecological quality, highlighting the importance of recognizing the prevalent metabolic paths and their intermediate byproducts. Various AMGs explained the variability between stations with poor vs. good ecological quality. Our study confirms the pivotal role of the virome content in ecosystem functioning, acting as a “pool” of available functions that may be transferred to the hosts. Further, it suggests that AMGs could be used as an ultra-sensitive metric of energy-production pathways with relevance in the vulnerable coastal zone and its ecological quality.
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Affiliation(s)
- Anastasia Tsiola
- Institute of Oceanography, Hellenic Centre for Marine Research, 71003 Heraklion Crete, Greece; (P.P.); (M.T.)
- Department of Biology, University of Crete, 70013 Heraklion Crete, Greece;
- Institute of Marine Biology, Biotechnology & Aquaculture, 71003 Heraklion Crete, Greece; (G.K.); (C.P.)
- Correspondence: ; Tel.: +30-2810-337713; Fax: +30-2810-337822
| | - Grégoire Michoud
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 23955-6900, Saudi Arabia; (G.M.); (S.F.); (D.D.)
| | - Stilianos Fodelianakis
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 23955-6900, Saudi Arabia; (G.M.); (S.F.); (D.D.)
| | - Ioannis Karakassis
- Department of Biology, University of Crete, 70013 Heraklion Crete, Greece;
| | - Georgios Kotoulas
- Institute of Marine Biology, Biotechnology & Aquaculture, 71003 Heraklion Crete, Greece; (G.K.); (C.P.)
| | - Alexandra Pavlidou
- Institute of Oceanography, Hellenic Centre for Marine Research, 19013 Anavyssos Attiki, Greece; (A.P.); (N.S.)
| | - Christina Pavloudi
- Institute of Marine Biology, Biotechnology & Aquaculture, 71003 Heraklion Crete, Greece; (G.K.); (C.P.)
| | - Paraskevi Pitta
- Institute of Oceanography, Hellenic Centre for Marine Research, 71003 Heraklion Crete, Greece; (P.P.); (M.T.)
| | - Nomiki Simboura
- Institute of Oceanography, Hellenic Centre for Marine Research, 19013 Anavyssos Attiki, Greece; (A.P.); (N.S.)
| | - Daniele Daffonchio
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 23955-6900, Saudi Arabia; (G.M.); (S.F.); (D.D.)
| | - Manolis Tsapakis
- Institute of Oceanography, Hellenic Centre for Marine Research, 71003 Heraklion Crete, Greece; (P.P.); (M.T.)
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23
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Wang W, Ren J, Tang K, Dart E, Ignacio-Espinoza JC, Fuhrman JA, Braun J, Sun F, Ahlgren NA. A network-based integrated framework for predicting virus-prokaryote interactions. NAR Genom Bioinform 2020; 2:lqaa044. [PMID: 32626849 PMCID: PMC7324143 DOI: 10.1093/nargab/lqaa044] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/12/2020] [Accepted: 06/05/2020] [Indexed: 12/12/2022] Open
Abstract
Metagenomic sequencing has greatly enhanced the discovery of viral genomic sequences; however, it remains challenging to identify the host(s) of these new viruses. We developed VirHostMatcher-Net, a flexible, network-based, Markov random field framework for predicting virus–prokaryote interactions using multiple, integrated features: CRISPR sequences and alignment-free similarity measures (\documentclass[12pt]{minimal}
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}{}$s_2^*$\end{document} and WIsH). Evaluation of this method on a benchmark set of 1462 known virus–prokaryote pairs yielded host prediction accuracy of 59% and 86% at the genus and phylum levels, representing 16–27% and 6–10% improvement, respectively, over previous single-feature prediction approaches. We applied our host prediction tool to crAssphage, a human gut phage, and two metagenomic virus datasets: marine viruses and viral contigs recovered from globally distributed, diverse habitats. Host predictions were frequently consistent with those of previous studies, but more importantly, this new tool made many more confident predictions than previous tools, up to nearly 3-fold more (n > 27 000), greatly expanding the diversity of known virus–host interactions.
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Affiliation(s)
- Weili Wang
- Quantitative and Computational Biology Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Jie Ren
- Quantitative and Computational Biology Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Kujin Tang
- Quantitative and Computational Biology Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Emily Dart
- Biology Department, Clark University, Worcester, MA 01610, USA
| | | | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Jonathan Braun
- Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Fengzhu Sun
- Quantitative and Computational Biology Program, University of Southern California, Los Angeles, CA 90089, USA
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24
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McKitterick AC, LeGault KN, Angermeyer A, Alam M, Seed KD. Competition between mobile genetic elements drives optimization of a phage-encoded CRISPR-Cas system: insights from a natural arms race. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180089. [PMID: 30905288 PMCID: PMC6452262 DOI: 10.1098/rstb.2018.0089] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CRISPR-Cas systems function as adaptive immune systems by acquiring nucleotide sequences called spacers that mediate sequence-specific defence against competitors. Uniquely, the phage ICP1 encodes a Type I-F CRISPR-Cas system that is deployed to target and overcome PLE, a mobile genetic element with anti-phage activity in Vibrio cholerae. Here, we exploit the arms race between ICP1 and PLE to examine spacer acquisition and interference under laboratory conditions to reconcile findings from wild populations. Natural ICP1 isolates encode multiple spacers directed against PLE, but we find that single spacers do not interfere equally with PLE mobilization. High-throughput sequencing to assay spacer acquisition reveals that ICP1 can also acquire spacers that target the V. cholerae chromosome. We find that targeting the V. cholerae chromosome proximal to PLE is sufficient to block PLE and is dependent on Cas2-3 helicase activity. We propose a model in which indirect chromosomal spacers are able to circumvent PLE by Cas2-3-mediated processive degradation of the V. cholerae chromosome before PLE mobilization. Generally, laboratory-acquired spacers are much more diverse than the subset of spacers maintained by ICP1 in nature, showing how evolutionary pressures can constrain CRISPR-Cas targeting in ways that are often not appreciated through in vitro analyses. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.
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Affiliation(s)
- Amelia C McKitterick
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Kristen N LeGault
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Angus Angermeyer
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Munirul Alam
- 2 International Centre for Diarrhoeal Disease Research , Dhaka , Bangladesh
| | - Kimberley D Seed
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA.,3 Chan Zuckerberg Biohub , San Francisco, CA 94158 , USA
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25
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Moore RM, Harrison AO, McAllister SM, Polson SW, Wommack KE. Iroki: automatic customization and visualization of phylogenetic trees. PeerJ 2020; 8:e8584. [PMID: 32149022 PMCID: PMC7049256 DOI: 10.7717/peerj.8584] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/17/2020] [Indexed: 12/26/2022] Open
Abstract
Phylogenetic trees are an important analytical tool for evaluating community diversity and evolutionary history. In the case of microorganisms, the decreasing cost of sequencing has enabled researchers to generate ever-larger sequence datasets, which in turn have begun to fill gaps in the evolutionary history of microbial groups. However, phylogenetic analyses of these types of datasets create complex trees that can be challenging to interpret. Scientific inferences made by visual inspection of phylogenetic trees can be simplified and enhanced by customizing various parts of the tree. Yet, manual customization is time-consuming and error prone, and programs designed to assist in batch tree customization often require programming experience or complicated file formats for annotation. Iroki, a user-friendly web interface for tree visualization, addresses these issues by providing automatic customization of large trees based on metadata contained in tab-separated text files. Iroki’s utility for exploring biological and ecological trends in sequencing data was demonstrated through a variety of microbial ecology applications in which trees with hundreds to thousands of leaf nodes were customized according to extensive collections of metadata. The Iroki web application and documentation are available at https://www.iroki.net or through the VIROME portal http://virome.dbi.udel.edu. Iroki’s source code is released under the MIT license and is available at https://github.com/mooreryan/iroki.
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Affiliation(s)
- Ryan M Moore
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
| | - Amelia O Harrison
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States of America
| | - Sean M McAllister
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States of America
| | - Shawn W Polson
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
| | - K Eric Wommack
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
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26
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Coutinho FH, Edwards RA, Rodríguez-Valera F. Charting the diversity of uncultured viruses of Archaea and Bacteria. BMC Biol 2019. [PMID: 31884971 DOI: 10.1101/480491v1.full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND Viruses of Archaea and Bacteria are among the most abundant and diverse biological entities on Earth. Unraveling their biodiversity has been challenging due to methodological limitations. Recent advances in culture-independent techniques, such as metagenomics, shed light on the unknown viral diversity, revealing thousands of new viral nucleotide sequences at an unprecedented scale. However, these novel sequences have not been properly classified and the evolutionary associations between them were not resolved. RESULTS Here, we performed phylogenomic analysis of nearly 200,000 viral nucleotide sequences to establish GL-UVAB: Genomic Lineages of Uncultured Viruses of Archaea and Bacteria. The pan-genome content of the identified lineages shed light on some of their infection strategies, potential to modulate host physiology, and mechanisms to escape host resistance systems. Furthermore, using GL-UVAB as a reference database for annotating metagenomes revealed elusive habitat distribution patterns of viral lineages and environmental drivers of community composition. CONCLUSIONS These findings provide insights about the genomic diversity and ecology of viruses of prokaryotes. The source code used in these analyses is freely available at https://sourceforge.net/projects/gluvab/.
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Affiliation(s)
- F H Coutinho
- Evolutionary Genomics Group, Departamento de Produccíon Vegetal y Microbiología, Universidad Miguel Hernández, Campus San Juan, San Juan, 03550, Alicante, Spain.
| | - R A Edwards
- Viral Information Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92128, USA
| | - F Rodríguez-Valera
- Evolutionary Genomics Group, Departamento de Produccíon Vegetal y Microbiología, Universidad Miguel Hernández, Campus San Juan, San Juan, 03550, Alicante, Spain
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27
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Coutinho FH, Edwards RA, Rodríguez-Valera F. Charting the diversity of uncultured viruses of Archaea and Bacteria. BMC Biol 2019; 17:109. [PMID: 31884971 PMCID: PMC6936153 DOI: 10.1186/s12915-019-0723-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 11/13/2019] [Indexed: 12/21/2022] Open
Abstract
Background Viruses of Archaea and Bacteria are among the most abundant and diverse biological entities on Earth. Unraveling their biodiversity has been challenging due to methodological limitations. Recent advances in culture-independent techniques, such as metagenomics, shed light on the unknown viral diversity, revealing thousands of new viral nucleotide sequences at an unprecedented scale. However, these novel sequences have not been properly classified and the evolutionary associations between them were not resolved. Results Here, we performed phylogenomic analysis of nearly 200,000 viral nucleotide sequences to establish GL-UVAB: Genomic Lineages of Uncultured Viruses of Archaea and Bacteria. The pan-genome content of the identified lineages shed light on some of their infection strategies, potential to modulate host physiology, and mechanisms to escape host resistance systems. Furthermore, using GL-UVAB as a reference database for annotating metagenomes revealed elusive habitat distribution patterns of viral lineages and environmental drivers of community composition. Conclusions These findings provide insights about the genomic diversity and ecology of viruses of prokaryotes. The source code used in these analyses is freely available at https://sourceforge.net/projects/gluvab/.
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Affiliation(s)
- F H Coutinho
- Evolutionary Genomics Group, Departamento de Produccíon Vegetal y Microbiología, Universidad Miguel Hernández, Campus San Juan, San Juan, 03550, Alicante, Spain.
| | - R A Edwards
- Viral Information Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92128, USA
| | - F Rodríguez-Valera
- Evolutionary Genomics Group, Departamento de Produccíon Vegetal y Microbiología, Universidad Miguel Hernández, Campus San Juan, San Juan, 03550, Alicante, Spain
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28
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Sommers P, Fontenele RS, Kringen T, Kraberger S, Porazinska DL, Darcy JL, Schmidt SK, Varsani A. Single-Stranded DNA Viruses in Antarctic Cryoconite Holes. Viruses 2019; 11:E1022. [PMID: 31689942 PMCID: PMC6893807 DOI: 10.3390/v11111022] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 10/28/2019] [Accepted: 10/31/2019] [Indexed: 12/28/2022] Open
Abstract
Antarctic cryoconite holes, or small melt-holes in the surfaces of glaciers, create habitable oases for isolated microbial communities with tightly linked microbial population structures. Viruses may influence the dynamics of polar microbial communities, but the viromes of the Antarctic cryoconite holes have yet to be characterized. We characterize single-stranded DNA (ssDNA) viruses from three cryoconite holes in the Taylor Valley, Antarctica, using metagenomics. Half of the assembled metagenomes cluster with those in the viral family Microviridae (n = 7), and the rest with unclassified circular replication associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses (n = 7). An additional 18 virus-like circular molecules encoding either a Rep, a capsid protein gene, or other unidentified but viral-like open reading frames were identified. The samples from which the genomes were identified show a strong gradient in microbial diversity and abundances, and the number of viral genomes detected in each sample mirror that gradient. Additionally, one of the CRESS genomes assembled here shares ~90% genome-wide pairwise identity with a virus identified from a freshwater pond on the McMurdo Ice Shelf (Antarctica). Otherwise, the similarity of these viruses to those previously identified is relatively low. Together, these patterns are consistent with the presence of a unique regional virome present in fresh water host populations of the McMurdo Dry Valley region.
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Affiliation(s)
- Pacifica Sommers
- Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - Rafaela S Fontenele
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287-5001, USA.
| | - Tayele Kringen
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287-5001, USA.
| | - Simona Kraberger
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287-5001, USA.
| | - Dorota L Porazinska
- Entomology and Nematology Department, University of Florida, Gainesville, FL 32611, USA.
| | - John L Darcy
- Division of Biomedical Informatics and Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Steven K Schmidt
- Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287-5001, USA.
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, Observatory, Cape Town 7701, South Africa.
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29
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Dávila-Ramos S, Castelán-Sánchez HG, Martínez-Ávila L, Sánchez-Carbente MDR, Peralta R, Hernández-Mendoza A, Dobson ADW, Gonzalez RA, Pastor N, Batista-García RA. A Review on Viral Metagenomics in Extreme Environments. Front Microbiol 2019; 10:2403. [PMID: 31749771 PMCID: PMC6842933 DOI: 10.3389/fmicb.2019.02403] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/04/2019] [Indexed: 12/22/2022] Open
Abstract
Viruses are the most abundant biological entities in the biosphere, and have the ability to infect Bacteria, Archaea, and Eukaryotes. The virome is estimated to be at least ten times more abundant than the microbiome with 107 viruses per milliliter and 109 viral particles per gram in marine waters and sediments or soils, respectively. Viruses represent a largely unexplored genetic diversity, having an important role in the genomic plasticity of their hosts. Moreover, they also play a significant role in the dynamics of microbial populations. In recent years, metagenomic approaches have gained increasing popularity in the study of environmental viromes, offering the possibility of extending our knowledge related to both virus diversity and their functional characterization. Extreme environments represent an interesting source of both microbiota and their virome due to their particular physicochemical conditions, such as very high or very low temperatures and >1 atm hydrostatic pressures, among others. Despite the fact that some progress has been made in our understanding of the ecology of the microbiota in these habitats, few metagenomic studies have described the viromes present in extreme ecosystems. Thus, limited advances have been made in our understanding of the virus community structure in extremophilic ecosystems, as well as in their biotechnological potential. In this review, we critically analyze recent progress in metagenomic based approaches to explore the viromes in extreme environments and we discuss the potential for new discoveries, as well as methodological challenges and perspectives.
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Affiliation(s)
- Sonia Dávila-Ramos
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Hugo G Castelán-Sánchez
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Liliana Martínez-Ávila
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | | | - Raúl Peralta
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Armando Hernández-Mendoza
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Alan D W Dobson
- School of Microbiology, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Ramón A Gonzalez
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Nina Pastor
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
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30
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Garretto A, Hatzopoulos T, Putonti C. virMine: automated detection of viral sequences from complex metagenomic samples. PeerJ 2019; 7:e6695. [PMID: 30993039 PMCID: PMC6462185 DOI: 10.7717/peerj.6695] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/26/2019] [Indexed: 12/29/2022] Open
Abstract
Metagenomics has enabled sequencing of viral communities from a myriad of different environments. Viral metagenomic studies routinely uncover sequences with no recognizable homology to known coding regions or genomes. Nevertheless, complete viral genomes have been constructed directly from complex community metagenomes, often through tedious manual curation. To address this, we developed the software tool virMine to identify viral genomes from raw reads representative of viral or mixed (viral and bacterial) communities. virMine automates sequence read quality control, assembly, and annotation. Researchers can easily refine their search for a specific study system and/or feature(s) of interest. In contrast to other viral genome detection tools that often rely on the recognition of viral signature sequences, virMine is not restricted by the insufficient representation of viral diversity in public data repositories. Rather, viral genomes are identified through an iterative approach, first omitting non-viral sequences. Thus, both relatives of previously characterized viruses and novel species can be detected, including both eukaryotic viruses and bacteriophages. Here we present virMine and its analysis of synthetic communities as well as metagenomic data sets from three distinctly different environments: the gut microbiota, the urinary microbiota, and freshwater viromes. Several new viral genomes were identified and annotated, thus contributing to our understanding of viral genetic diversity in these three environments.
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Affiliation(s)
- Andrea Garretto
- Bioinformatics Program, Loyola University of Chicago, Chicago, IL, United States of America
| | - Thomas Hatzopoulos
- Department of Computer Science, Loyola University of Chicago, Chicago, IL, United States of America
| | - Catherine Putonti
- Bioinformatics Program, Loyola University of Chicago, Chicago, IL, United States of America.,Department of Computer Science, Loyola University of Chicago, Chicago, IL, United States of America.,Department of Biology, Loyola University of Chicago, Chicago, IL, United States of America.,Department of Microbiology and Immunology, Loyola University of Chicago, Maywood, IL, United States of America
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Margesin R, Collins T. Microbial ecology of the cryosphere (glacial and permafrost habitats): current knowledge. Appl Microbiol Biotechnol 2019; 103:2537-2549. [PMID: 30719551 PMCID: PMC6443599 DOI: 10.1007/s00253-019-09631-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 11/28/2022]
Abstract
Microorganisms in cold ecosystems play a key ecological role in their natural habitats. Since these ecosystems are especially sensitive to climate changes, as indicated by the worldwide retreat of glaciers and ice sheets as well as permafrost thawing, an understanding of the role and potential of microbial life in these habitats has become crucial. Emerging technologies have added significantly to our knowledge of abundance, functional activity, and lifestyles of microbial communities in cold environments. The current knowledge of microbial ecology in glacial habitats and permafrost, the most studied habitats of the cryosphere, is reported in this review.
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Affiliation(s)
- Rosa Margesin
- Institute of Microbiology, University of Innsbruck, 6020, Innsbruck, Austria.
| | - Tony Collins
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057, Braga, Portugal
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32
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Abstract
Bacteriophages, discovered about a century ago, have been pivotal as models for understanding the fundamental principles of molecular biology. While interest in phage biology declined after the phage "golden era," key recent developments, including advances in phage genomics, microscopy, and the discovery of the CRISPR-Cas anti-phage defense system, have sparked a renaissance in phage research in the past decade. This review highlights recently discovered unexpected complexities in phage biology, describes a new arsenal of phage genes that help them overcome bacterial defenses, and discusses advances toward documentation of the phage biodiversity on a global scale.
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Affiliation(s)
- Gal Ofir
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rotem Sorek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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33
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Watkins SC, Sible E, Putonti C. Pseudomonas PB1-Like Phages: Whole Genomes from Metagenomes Offer Insight into an Abundant Group of Bacteriophages. Viruses 2018; 10:v10060331. [PMID: 29914169 PMCID: PMC6024596 DOI: 10.3390/v10060331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/11/2018] [Accepted: 06/11/2018] [Indexed: 02/07/2023] Open
Abstract
Despite the abundance, ubiquity and impact of environmental viruses, their inherent genomic plasticity and extreme diversity pose significant challenges for the examination of bacteriophages on Earth. Viral metagenomic studies have offered insight into broader aspects of phage ecology and repeatedly uncover genes to which we are currently unable to assign function. A combined effort of phage isolation and metagenomic survey of Chicago’s nearshore waters of Lake Michigan revealed the presence of Pbunaviruses, relatives of the Pseudomonas phage PB1. This prompted our expansive investigation of PB1-like phages. Genomic signatures of PB1-like phages and Pbunaviruses were identified, permitting the unambiguous distinction between the presence/absence of these phages in soils, freshwater and wastewater samples, as well as publicly available viral metagenomic datasets. This bioinformatic analysis led to the de novo assembly of nine novel PB1-like phage genomes from a metagenomic survey of samples collected from Lake Michigan. While this study finds that Pbunaviruses are abundant in various environments of Northern Illinois, genomic variation also exists to a considerable extent within individual communities.
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Affiliation(s)
- Siobhan C Watkins
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA.
| | - Emily Sible
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA.
| | - Catherine Putonti
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA.
- Department of Computer Science, Loyola University Chicago, Chicago, IL 60660, USA.
- Bioinformatics Program, Loyola University Chicago, Chicago, IL 60660, USA.
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34
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Abstract
Viruses play an important role in the control of microbial communities, and it has been suggested that the influence of viruses in polar ecosystems, with low nutrients and under extreme environmental conditions, may be greater. Viral metagenomics allows the genetic characterization of complex viral communities without the need to isolate and grow viruses. Recent investigations in Antarctica and the Arctic are uncovering a great diversity of DNA viruses, including bacteriophages, circular single-stranded DNA viruses, algal-infecting phycodnaviruses, and virophages, adapted to these extreme environments. The limited sequence similarity between viruses in Antarctica and the Arctic suggests that viral communities in the two polar regions have evolved independently since the formation of the Antarctic continent, estimated to occur 25 million years ago. The community of RNA viruses in Antarctica is dominated by the order Picornavirales and their quasispecies composition suggests that higher genetic variability may correlate with viral adaptation to new environmental conditions.
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35
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Chrismas NAM, Anesio AM, Sánchez-Baracaldo P. The future of genomics in polar and alpine cyanobacteria. FEMS Microbiol Ecol 2018; 94:4904125. [PMID: 29506259 PMCID: PMC5939894 DOI: 10.1093/femsec/fiy032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/23/2018] [Indexed: 01/01/2023] Open
Abstract
In recent years, genomic analyses have arisen as an exciting way of investigating the functional capacity and environmental adaptations of numerous micro-organisms of global relevance, including cyanobacteria. In the extreme cold of Arctic, Antarctic and alpine environments, cyanobacteria are of fundamental ecological importance as primary producers and ecosystem engineers. While their role in biogeochemical cycles is well appreciated, little is known about the genomic makeup of polar and alpine cyanobacteria. In this article, we present ways that genomic techniques might be used to further our understanding of cyanobacteria in cold environments in terms of their evolution and ecology. Existing examples from other environments (e.g. marine/hot springs) are used to discuss how methods developed there might be used to investigate specific questions in the cryosphere. Phylogenomics, comparative genomics and population genomics are identified as methods for understanding the evolution and biogeography of polar and alpine cyanobacteria. Transcriptomics will allow us to investigate gene expression under extreme environmental conditions, and metagenomics can be used to complement tradition amplicon-based methods of community profiling. Finally, new techniques such as single cell genomics and metagenome assembled genomes will also help to expand our understanding of polar and alpine cyanobacteria that cannot readily be cultured.
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Affiliation(s)
- Nathan A M Chrismas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Alexandre M Anesio
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
| | - Patricia Sánchez-Baracaldo
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
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36
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Nishimura Y, Yoshida T, Kuronishi M, Uehara H, Ogata H, Goto S. ViPTree: the viral proteomic tree server. Bioinformatics 2018; 33:2379-2380. [PMID: 28379287 DOI: 10.1093/bioinformatics/btx157] [Citation(s) in RCA: 332] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/21/2017] [Indexed: 11/12/2022] Open
Abstract
Summary ViPTree is a web server provided through GenomeNet to generate viral proteomic trees for classification of viruses based on genome-wide similarities. Users can upload viral genomes sequenced either by genomics or metagenomics. ViPTree generates proteomic trees for the uploaded genomes together with flexibly selected reference viral genomes. ViPTree also serves as a platform to visually investigate genomic alignments and automatically annotated gene functions for the uploaded viral genomes, thus providing virus researchers the first choice for classifying and understanding newly sequenced viral genomes. Availability and Implementation ViPTree is freely available at: http://www.genome.jp/viptree . Contact goto@kuicr.kyoto-u.ac.jp. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Yosuke Nishimura
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.,Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takashi Yoshida
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Megumi Kuronishi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hideya Uehara
- SGI Japan, Ltd., Yebisu Garden Place Tower 31F, 4-20-3 Ebisu, Shibuya-ku, Tokyo 150-6031, Japan
| | - Hiroyuki Ogata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Susumu Goto
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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37
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Tikhe CV, Husseneder C. Metavirome Sequencing of the Termite Gut Reveals the Presence of an Unexplored Bacteriophage Community. Front Microbiol 2018; 8:2548. [PMID: 29354098 PMCID: PMC5759034 DOI: 10.3389/fmicb.2017.02548] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/08/2017] [Indexed: 12/25/2022] Open
Abstract
The Formosan subterranean termite; Coptotermes formosanus is nutritionally dependent on the complex and diverse community of bacteria and protozoa in their gut. Although, there have been many studies to decipher the taxonomic and functional diversity of bacterial communities in the guts of termites, their bacteriophages remain unstudied. We sequenced the metavirome of the guts of Formosan subterranean termite workers to study the diversity of bacteriophages and other associated viruses. Results showed that the termites harbor a virome in their gut comprised of varied and previously unknown bacteriophages. Between 87-90% of the predicted dsDNA virus genes by Metavir showed similarity to the tailed bacteriophages (Caudovirales). Many predicted genes from the virome matched to bacterial prophage regions. These data are suggestive of a virome dominated by temperate bacteriophages. We predicted the genomes of seven novel Caudovirales bacteriophages from the termite gut. Three of these predicted bacteriophage genomes were found in high proportions in all the three termite colonies tested. Two bacteriophages are predicted to infect endosymbiotic bacteria of the gut protozoa. The presence of these putative bacteriophages infecting endosymbionts of the gut protozoa, suggests a quadripartite relationship between the termites their symbiotic protozoa, endosymbiotic bacteria of the protozoa and their bacteriophages. Other than Caudovirales, ss-DNA virus related genes were also present in the termite gut. We predicted the genomes of 12 novel Microviridae phages from the termite gut and seven of those possibly represent a new proposed subfamily. Circovirus like genomes were also assembled from the termite gut at lower relative abundance. We predicted 10 novel circovirus genomes in this study. Whether these circoviruses infect the termites remains elusive at the moment. The functional and taxonomical annotations suggest that the termites may harbor a core virome comprised of the bacteriophages infecting endosymbionts of the gut protozoa.
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Affiliation(s)
- Chinmay V Tikhe
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Claudia Husseneder
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
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38
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Shi W, Li J, Zhou H, Gao GF. Pathogen genomic surveillance elucidates the origins, transmission and evolution of emerging viral agents in China. SCIENCE CHINA. LIFE SCIENCES 2017; 60:1317-1330. [PMID: 29270793 PMCID: PMC7088571 DOI: 10.1007/s11427-017-9211-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/01/2017] [Indexed: 02/06/2023]
Abstract
In the past twenty years, numerous novel zoonotic viral agents with pandemic potential have emerged in China, such as the severe acute respiratory syndrome (SARS) coronavirus and, more recently, the avian-origin influenza A/H7N9 virus, which have caused outbreaks among humans with high morbidity and mortality. In addition, several emerging and re-emerging viral pathogens have also been imported into China from travelers, e.g. the Middle East respiratory syndrome (MERS) coronavirus and Zika virus (ZIKV). Herein, we review these emerging viral pathogens in China and focus on how surveillance by pathogen genomics has been employed to discover and annotate novel pathogenic agents, identify natural reservoirs, monitor the transmission events and delineate their evolution and adaption to the human host. We also highlight the application of genomic sequencing in the recent Ebola epidemics in Western Africa. In summary, genomic sequencing has become a standard research tool in the field of emerging infectious diseases which has been proven invaluable in containing these viral infections and reducing burden of disease in humans and animals. Genomic surveillance of pathogenic agents will serve as a key epidemiological and research tool in the modern era of precision infectious diseases and in the future studies of virosphere.
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Affiliation(s)
- Weifeng Shi
- Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong (Taishan Medical College), Taishan Medical College, Taian, 271000, China.
| | - Juan Li
- Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong (Taishan Medical College), Taishan Medical College, Taian, 271000, China
| | - Hong Zhou
- Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong (Taishan Medical College), Taishan Medical College, Taian, 271000, China
| | - George F Gao
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, 102206, China
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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39
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CRISPR-Cas-Mediated Gene Silencing Reveals RacR To Be a Negative Regulator of YdaS and YdaT Toxins in Escherichia coli K-12. mSphere 2017; 2:mSphere00483-17. [PMID: 29205229 PMCID: PMC5700377 DOI: 10.1128/msphere.00483-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 10/20/2017] [Indexed: 01/05/2023] Open
Abstract
racR is an essential gene and one of the many poorly studied genes found on the rac prophage element that is present in many Escherichia coli genomes. Employing a CRISPR-based approach, we have silenced racR expression to various levels and elucidated its physiological consequences. We show that the downregulation of racR leads to upregulation of the adjacent ydaS-ydaT operon. Both YdaS and YdaT act as toxins by perturbing the cell division resulting in enhanced cell killing. This work establishes a physiological role for RacR, which is to keep the toxic effects of YdaS and YdaT in check and promote cell survival. We, thus, provide a rationale for the essentiality of racR in Escherichia coli K-12 strains. Bacterial genomes are rich in horizontally acquired prophages. racR is an essential gene located in the rac prophage that is resident in many Escherichia coli genomes. Employing a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas-based gene silencing approach, we show that RacR is a negative regulator of the divergently transcribed and adjacent ydaS-ydaT operon in Escherichia coli K-12. Overexpression of YdaS and YdaT due to RacR depletion leads to cell division defects and decrease in survival. We further show that both YdaS and YdaT can act independently as toxins and that RacR serves to counteract the toxicity by tightly downregulating the expression of these toxins. IMPORTANCEracR is an essential gene and one of the many poorly studied genes found on the rac prophage element that is present in many Escherichia coli genomes. Employing a CRISPR-based approach, we have silenced racR expression to various levels and elucidated its physiological consequences. We show that the downregulation of racR leads to upregulation of the adjacent ydaS-ydaT operon. Both YdaS and YdaT act as toxins by perturbing the cell division resulting in enhanced cell killing. This work establishes a physiological role for RacR, which is to keep the toxic effects of YdaS and YdaT in check and promote cell survival. We, thus, provide a rationale for the essentiality of racR in Escherichia coli K-12 strains.
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40
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Koonin EV, Makarova KS. Mobile Genetic Elements and Evolution of CRISPR-Cas Systems: All the Way There and Back. Genome Biol Evol 2017; 9:2812-2825. [PMID: 28985291 PMCID: PMC5737515 DOI: 10.1093/gbe/evx192] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2017] [Indexed: 12/13/2022] Open
Abstract
The Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-CRISPR-associated proteins (Cas) systems of bacterial and archaeal adaptive immunity show multifaceted evolutionary relationships with at least five classes of mobile genetic elements (MGE). First, the adaptation module of CRISPR-Cas that is responsible for the formation of the immune memory apparently evolved from a Casposon, a self-synthesizing transposon that employs the Cas1 protein as the integrase and might have brought additional cas genes to the emerging immunity loci. Second, a large subset of type III CRISPR-Cas systems recruited a reverse transcriptase from a Group II intron, providing for spacer acquisition from RNA. Third, effector nucleases of Class 2 CRISPR-Cas systems that are responsible for the recognition and cleavage of the target DNA were derived from transposon-encoded TnpB nucleases, most likely, on several independent occasions. Fourth, accessory nucleases in some variants of types I and III toxin and type VI effectors RNases appear to be ultimately derived from toxin nucleases of microbial toxin-antitoxin modules. Fifth, the opposite direction of evolution is manifested in the recruitment of CRISPR-Cas systems by a distinct family of Tn7-like transposons that probably exploit the capacity of CRISPR-Cas to recognize unique DNA sites to facilitate transposition as well as by bacteriophages that employ them to cope with host defense. Additionally, individual Cas proteins, such as the Cas4 nuclease, were recruited by bacteriophages and transposons. The two-sided evolutionary connection between CRISPR-Cas and MGE fits the "guns for hire" paradigm whereby homologous enzymatic machineries, in particular nucleases, are shuttled between MGE and defense systems and are used alternately as means of offense or defense.
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Affiliation(s)
- Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland
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41
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Disentangling the origins of virophages and polintons. Curr Opin Virol 2017; 25:59-65. [PMID: 28802203 DOI: 10.1016/j.coviro.2017.07.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/10/2017] [Accepted: 07/14/2017] [Indexed: 01/04/2023]
Abstract
Virophages and polintons are part of a complex system that also involves eukaryotes, giant viruses, as well as other viruses and transposable elements. Virophages are cosmopolitan, being found in environments ranging from the Amazon River to Antarctic hypersaline lakes, while polintons are found in many single celled and multicellular eukaryotes. Virophages and polintons have a shared ancestry, but their exact origins are unknown and obscured by antiquity and extensive horizontal gene transfer (HGT). Paleovirology can help disentangle the complicated gene flow between these two, as well as their giant viral and eukaryotic hosts. We outline the evidence and theoretical support for polintons being descended from viruses and not vice versa. In order to disentangle the natural history of polintons and virophages, we suggest that there is much to be gained by embracing rigorous metagenomics and evolutionary analyses. Methods from paleovirology will play a pivotal role in unravelling ancient relationships, HGT and patterns of cross-species transmission.
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42
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Adriaenssens EM, Kramer R, Van Goethem MW, Makhalanyane TP, Hogg I, Cowan DA. Environmental drivers of viral community composition in Antarctic soils identified by viromics. MICROBIOME 2017; 5:83. [PMID: 28724405 PMCID: PMC5518109 DOI: 10.1186/s40168-017-0301-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 07/06/2017] [Indexed: 05/18/2023]
Abstract
BACKGROUND The Antarctic continent is considered the coldest and driest place on earth with simple ecosystems, devoid of higher plants. Soils in the ice-free regions of Antarctica are known to harbor a wide range of microorganisms from primary producers to grazers, yet their ecology and particularly the role of viruses is poorly understood. In this study, we examined the virus community structures of 14 soil samples from the Mackay Glacier region. METHODS Viral communities were extracted from soil and the dsDNA was extracted, amplified using single-primer amplification, and sequenced using the Ion Torrent Proton platform. Metadata on soil physico-chemistry was collected from all sites. Both read and contig datasets were analyzed with reference-independent and reference-dependent methods to assess viral community structures and the influence of environmental parameters on their distribution. RESULTS We observed a high heterogeneity in virus signatures, independent of geographical proximity. Tailed bacteriophages were dominant in all samples, but the incidences of the affiliated families Siphoviridae and Myoviridae were inversely correlated, suggesting direct competition for hosts. Viruses of the families Phycodnaviridae and Mimiviridae were present at significant levels in high-diversity soil samples and were found to co-occur, implying little competition between them. Combinations of soil factors, including pH, calcium content, and site altitude, were found to be the main drivers of viral community structure. CONCLUSIONS The pattern of viral community structure with higher levels of diversity at lower altitude and pH, and co-occurring viral families, suggests that these cold desert soil viruses interact with each other, the host, and the environment in an intricate manner, playing a potentially crucial role in maintaining host diversity and functioning of the microbial ecosystem in the extreme environments of Antarctic soil.
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Affiliation(s)
- Evelien M. Adriaenssens
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB UK
| | - Rolf Kramer
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Marc W. Van Goethem
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Thulani P. Makhalanyane
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Ian Hogg
- School of Science, University of Waikato, Hamilton, New Zealand
- Polar Knowledge Canada, 170 Laurier Avenue West, Ottawa, Ontario K1P 5V5 Canada
| | - Don A. Cowan
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
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43
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Anesio AM, Lutz S, Chrismas NAM, Benning LG. The microbiome of glaciers and ice sheets. NPJ Biofilms Microbiomes 2017; 3:10. [PMID: 28649411 PMCID: PMC5460203 DOI: 10.1038/s41522-017-0019-0] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/17/2017] [Accepted: 03/23/2017] [Indexed: 01/09/2023] Open
Abstract
Glaciers and ice sheets, like other biomes, occupy a significant area of the planet and harbour biological communities with distinct interactions and feedbacks with their physical and chemical environment. In the case of the glacial biome, the biological processes are dominated almost exclusively by microbial communities. Habitats on glaciers and ice sheets with enough liquid water to sustain microbial activity include snow, surface ice, cryoconite holes, englacial systems and the interface between ice and overridden rock/soil. There is a remarkable similarity between the different specific glacial habitats across glaciers and ice sheets worldwide, particularly regarding their main primary producers and ecosystem engineers. At the surface, cyanobacteria dominate the carbon production in aquatic/sediment systems such as cryoconite holes, while eukaryotic Zygnematales and Chlamydomonadales dominate ice surfaces and snow dynamics, respectively. Microbially driven chemolithotrophic processes associated with sulphur and iron cycle and C transformations in subglacial ecosystems provide the basis for chemical transformations at the rock interface under the ice that underpin an important mechanism for the delivery of nutrients to downstream ecosystems. In this review, we focus on the main ecosystem engineers of glaciers and ice sheets and how they interact with their chemical and physical environment. We then discuss the implications of this microbial activity on the icy microbiome to the biogeochemistry of downstream ecosystems.
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Affiliation(s)
- Alexandre M. Anesio
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS UK
| | - Stefanie Lutz
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Nathan A. M. Chrismas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS UK
| | - Liane G. Benning
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Department of Earth Sciences, Free University of Berlin, 12249 Berlin, Germany
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44
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Environmental Viral Genomes Shed New Light on Virus-Host Interactions in the Ocean. mSphere 2017; 2:mSphere00359-16. [PMID: 28261669 PMCID: PMC5332604 DOI: 10.1128/msphere.00359-16] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/02/2017] [Indexed: 11/27/2022] Open
Abstract
Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes. Metagenomics has revealed the existence of numerous uncharacterized viral lineages, which are referred to as viral “dark matter.” However, our knowledge regarding viral genomes is biased toward culturable viruses. In this study, we analyzed 1,600 (1,352 nonredundant) complete double-stranded DNA viral genomes (10 to 211 kb) assembled from 52 marine viromes. Together with 244 previously reported uncultured viral genomes, a genome-wide comparison delineated 617 genus-level operational taxonomic units (OTUs) for these environmental viral genomes (EVGs). Of these, 600 OTUs contained no representatives from known viruses, thus putatively corresponding to novel viral genera. Predicted hosts of the EVGs included major groups of marine prokaryotes, such as marine group II Euryarchaeota and SAR86, from which no viruses have been isolated to date, as well as Flavobacteriaceae and SAR116. Our analysis indicates that marine cyanophages are already well represented in genome databases and that one of the EVGs likely represents a new cyanophage lineage. Several EVGs encode many enzymes that appear to function for an efficient utilization of iron-sulfur clusters or to enhance host survival. This suggests that there is a selection pressure on these marine viruses to accumulate genes for specific viral propagation strategies. Finally, we revealed that EVGs contribute to a 4-fold increase in the recruitment of photic-zone viromes compared with the use of current reference viral genomes. IMPORTANCE Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes.
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Grazziotin AL, Koonin EV, Kristensen DM. Prokaryotic Virus Orthologous Groups (pVOGs): a resource for comparative genomics and protein family annotation. Nucleic Acids Res 2016; 45:D491-D498. [PMID: 27789703 PMCID: PMC5210652 DOI: 10.1093/nar/gkw975] [Citation(s) in RCA: 217] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/08/2016] [Accepted: 10/21/2016] [Indexed: 11/13/2022] Open
Abstract
Viruses are the most abundant and diverse biological entities on earth, and while most of this diversity remains completely unexplored, advances in genome sequencing have provided unprecedented glimpses into the virosphere. The Prokaryotic Virus Orthologous Groups (pVOGs, formerly called Phage Orthologous Groups, POGs) resource has aided in this task over the past decade by using automated methods to keep pace with the rapid increase in genomic data. The uses of pVOGs include functional annotation of viral proteins, identification of genes and viruses in uncharacterized DNA samples, phylogenetic analysis, large-scale comparative genomics projects, and more. The pVOGs database represents a comprehensive set of orthologous gene families shared across multiple complete genomes of viruses that infect bacterial or archaeal hosts (viruses of eukaryotes will be added at a future date). The pVOGs are constructed within the Clusters of Orthologous Groups (COGs) framework that is widely used for orthology identification in prokaryotes. Since the previous release of the POGs, the size has tripled to nearly 3000 genomes and 300 000 proteins, and the number of conserved orthologous groups doubled to 9518. User-friendly webpages are available, including multiple sequence alignments and HMM profiles for each VOG. These changes provide major improvements to the pVOGs database, at a time of rapid advances in virus genomics. The pVOGs database is hosted jointly at the University of Iowa at http://dmk-brain.ecn.uiowa.edu/pVOGs and the NCBI at ftp://ftp.ncbi.nlm.nih.gov/pub/kristensen/pVOGs/home.html.
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Affiliation(s)
- Ana Laura Grazziotin
- Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - David M Kristensen
- Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, IA 52242, USA .,National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Rassner SME, Anesio AM, Girdwood SE, Hell K, Gokul JK, Whitworth DE, Edwards A. Can the Bacterial Community of a High Arctic Glacier Surface Escape Viral Control? Front Microbiol 2016; 7:956. [PMID: 27446002 PMCID: PMC4914498 DOI: 10.3389/fmicb.2016.00956] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/02/2016] [Indexed: 02/05/2023] Open
Abstract
Glacial ice surfaces represent a seasonally evolving three-dimensional photic zone which accumulates microbial biomass and potentiates positive feedbacks in ice melt. Since viruses are abundant in glacial systems and may exert controls on supraglacial bacterial production, we examined whether changes in resource availability would promote changes in the bacterial community and the dynamics between viruses and bacteria of meltwater from the photic zone of a Svalbard glacier. Our results indicated that, under ambient nutrient conditions, low estimated viral decay rates account for a strong viral control of bacterial productivity, incurring a potent viral shunt of a third of bacterial carbon in the supraglacial microbial loop. Moreover, it appears that virus particles are very stable in supraglacial meltwater, raising the prospect that viruses liberated in melt are viable downstream. However, manipulating resource availability as dissolved organic carbon, nitrogen, and phosphorous in experimental microcosms demonstrates that the photic zone bacterial communities can escape viral control. This is evidenced by a marked decline in virus-to-bacterium ratio (VBR) concomitant with increased bacterial productivity and number. Pyrosequencing shows a few bacterial taxa, principally Janthinobacterium sp., dominate both the source meltwater and microcosm communities. Combined, our results suggest that viruses maintain high VBR to promote contact with low-density hosts, by the manufacture of robust particles, but that this necessitates a trade-off which limits viral production. Consequently, dominant bacterial taxa appear to access resources to evade viral control. We propose that a delicate interplay of bacterial and viral strategies affects biogeochemical cycling upon glaciers and, ultimately, downstream ecosystems.
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Affiliation(s)
- Sara M E Rassner
- Institute of Biological, Rural and Environmental Sciences, Aberystwyth UniversityAberystwyth, UK; Department of Geography and Earth Sciences, Aberystwyth UniversityAberystwyth, UK
| | - Alexandre M Anesio
- School of Geographical Sciences, Bristol Glaciology Centre, University of Bristol Bristol, UK
| | - Susan E Girdwood
- Institute of Biological, Rural and Environmental Sciences, Aberystwyth University Aberystwyth, UK
| | - Katherina Hell
- Institute of Ecology, University of Innsbruck Innsbruck, Austria
| | - Jarishma K Gokul
- Institute of Biological, Rural and Environmental Sciences, Aberystwyth University Aberystwyth, UK
| | - David E Whitworth
- Institute of Biological, Rural and Environmental Sciences, Aberystwyth University Aberystwyth, UK
| | - Arwyn Edwards
- Institute of Biological, Rural and Environmental Sciences, Aberystwyth University Aberystwyth, UK
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Wang X, Wood TK. Cryptic prophages as targets for drug development. Drug Resist Updat 2016; 27:30-8. [PMID: 27449596 DOI: 10.1016/j.drup.2016.06.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 05/30/2016] [Accepted: 05/30/2016] [Indexed: 12/20/2022]
Abstract
Bacterial chromosomes may contain up to 20% phage DNA that encodes diverse proteins ranging from those for photosynthesis to those for autoimmunity; hence, phages contribute greatly to the metabolic potential of pathogens. Active prophages carrying genes encoding virulence factors and antibiotic resistance can be excised from the host chromosome to form active phages and are transmissible among different bacterial hosts upon SOS responses. Cryptic prophages are artifacts of mutagenesis in which lysogenic phage are captured in the bacterial chromosome: they may excise but they do not form active phage particles or lyse their captors. Hence, cryptic prophages are relatively permanent reservoirs of genes, many of which benefit pathogens, in ways we are just beginning to discern. Here we explore the role of active prophage- and cryptic prophage-derived proteins in terms of (i) virulence, (ii) antibiotic resistance, and (iii) antibiotic tolerance; antibiotic tolerance occurs as a result of the non-heritable phenotype of dormancy which is a result of activation of toxins of toxin/antitoxin loci that are frequently encoded in cryptic prophages. Therefore, cryptic prophages are promising targets for drug development.
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Affiliation(s)
- Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China.
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802-4400, United States; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802-4400, United States.
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Cai L, Zhang R, He Y, Feng X, Jiao N. Metagenomic Analysis of Virioplankton of the Subtropical Jiulong River Estuary, China. Viruses 2016; 8:v8020035. [PMID: 26848678 PMCID: PMC4776190 DOI: 10.3390/v8020035] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 11/24/2022] Open
Abstract
Viruses are the most abundant biological entities in the oceans, and encompass a significant reservoir of genetic diversity. However, little is known about their biodiversity in estuary environments, which represent a highly dynamic and potentially more diverse habitat. Here, we report a metagenomic analysis of the dsDNA viral community from the Jiulong River Estuary (JRE), China, and provide a comparative analysis with other closely related environments. The results showed that the majority of JRE virome did not show any significant similarity to the database. For the major viral group (Caudovirales) detected in the sample, Podoviridae (44.88%) were the most abundant family, followed by Siphoviridae (32.98%) and Myoviridae (17.32%). The two most abundant viruses identified in the virome were phages HTVC010P and HMO-2011, which infect bacteria belonging to marine SAR11 and SAR116 clades, respectively. Two contigs larger than 20 kb, which show similar overall genome architectures to Celeribacter phage P12053L and Thalosomonas phage BA3, respectively, were generated during assembly. Comparative analysis showed that the JRE virome was more similar to marine viromes than to freshwater viromes, and shared a relative coarse-grain genetic overlap (averaging 14.14% ± 1.68%) with other coastal viromes. Our study indicated that the diversity and community structure of the virioplankton found in JRE were mainly affected by marine waters, with less influence from freshwater discharge.
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Affiliation(s)
- Lanlan Cai
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University (Xiang'an), Xiamen 361005, China.
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University (Xiang'an), Xiamen 361005, China.
| | - Ying He
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Xiaoyuan Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University (Xiang'an), Xiamen 361005, China.
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Gong C, Zhang W, Zhou X, Wang H, Sun G, Xiao J, Pan Y, Yan S, Wang Y. Novel Virophages Discovered in a Freshwater Lake in China. Front Microbiol 2016; 7:5. [PMID: 26834726 PMCID: PMC4722103 DOI: 10.3389/fmicb.2016.00005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/05/2016] [Indexed: 12/22/2022] Open
Abstract
Virophages are small double-stranded DNA viruses that are parasites of giant DNA viruses that infect unicellular eukaryotes. Here we identify a novel group of virophages, named Dishui Lake virophages (DSLVs) that were discovered in Dishui Lake (DSL): an artificial freshwater lake in Shanghai, China. Based on PCR and metagenomic analysis, the complete genome of DSLV1 was found to be circular and 28,788 base pairs in length, with a G+C content 43.2%, and 28 predicted open reading frames (ORFs). Fifteen of the DSLV1 ORFs have sequence similarity to known virophages. Two DSLV1 ORFs exhibited sequence similarity to that of prasinoviruses (Phycodnaviridae) and chloroviruses (Phycodnaviridae), respectively, suggesting horizontal gene transfer occurred between these large algal DNA viruses and DSLV1. 46 other virophages-related contigs were also obtained, including six homologous major capsid protein (MCP) gene. Phylogenetic analysis of these MCPs showed that DSLVs are closely related to OLV (Organic Lake virophage) and YSLVs (Yellowstone Lake virophages), especially to YSLV3, except for YSLV7. These results indicate that freshwater ecotopes are the hotbed for discovering novel virophages as well as understanding their diversity and properties.
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Affiliation(s)
- Chaowen Gong
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Weijia Zhang
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Xuewen Zhou
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Hongming Wang
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Guowei Sun
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Jinzhou Xiao
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
| | - Shuling Yan
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Institute of Biochemistry and Molecular Cell Biology, University of GoettingenGoettingen, Germany
| | - Yongjie Wang
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of AgricultureShanghai, China
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Acidianus Tailed Spindle Virus: a New Archaeal Large Tailed Spindle Virus Discovered by Culture-Independent Methods. J Virol 2016; 90:3458-68. [PMID: 26763997 DOI: 10.1128/jvi.03098-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/07/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The field of viral metagenomics has expanded our understanding of viral diversity from all three domains of life (Archaea, Bacteria, and Eukarya). Traditionally, viral metagenomic studies provide information about viral gene content but rarely provide knowledge about virion morphology and/or cellular host identity. Here we describe a new virus, Acidianus tailed spindle virus (ATSV), initially identified by bioinformatic analysis of viral metagenomic data sets from a high-temperature (80°C) acidic (pH 2) hot spring located in Yellowstone National Park, followed by more detailed characterization using only environmental samples without dependency on culturing. Characterization included the identification of the large tailed spindle virion morphology, determination of the complete 70.8-kb circular double-stranded DNA (dsDNA) viral genome content, and identification of its cellular host. Annotation of the ATSV genome revealed a potential three-domain gene product containing an N-terminal leucine-rich repeat domain, followed by a likely posttranslation regulatory region consisting of high serine and threonine content, and a C-terminal ESCRT-III domain, suggesting interplay with the host ESCRT system. The host of ATSV, which is most closely related to Acidianus hospitalis, was determined by a combination of analysis of cellular clustered regularly interspaced short palindromic repeat (CRISPR)/Cas loci and dual viral and cellular fluorescence in situ hybridization (viral FISH) analysis of environmental samples and confirmed by culture-based infection studies. This work provides an expanded pathway for the discovery, isolation, and characterization of new viruses using culture-independent approaches and provides a platform for predicting and confirming virus hosts. IMPORTANCE Virus discovery and characterization have been traditionally accomplished by using culture-based methods. While a valuable approach, it is limited by the availability of culturable hosts. In this research, we report a virus-centered approach to virus discovery and characterization, linking viral metagenomic sequences to a virus particle, its sequenced genome, and its host directly in environmental samples, without using culture-dependent methods. This approach provides a pathway for the discovery, isolation, and characterization of new viruses. While this study used an acidic hot spring environment to characterize a new archaeal virus, Acidianus tailed spindle virus (ATSV), the approach can be generally applied to any environment to expand knowledge of virus diversity in all three domains of life.
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