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Kamran A, Li Y, Zhang W, Jiao Y, Farooq T, Wang Y, Liu D, Jiang L, Shen L, Wang F, Yang J. Insights into the genetic variability and evolutionary dynamics of tomato spotted wilt orthotospovirus in China. BMC Genomics 2024; 25:40. [PMID: 38191299 PMCID: PMC10773106 DOI: 10.1186/s12864-023-09951-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 12/28/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND Viral diseases are posing threat to annual production and quality of tobacco in China. Recently, tomato spotted wilt orthotospovirus (TSWV) has been reported to infect three major crops including tobacco. Current study was aimed to investigate the population dynamics and molecular diversity of the TSWV. In the current study, to assess and identify the prevalence and evolutionary history of TSWV in tobacco crops in China, full-length genome sequences of TSWV isolates from tobacco, were identified and analyzed. METHODS After trimming and validation, sequences of new isolates were submitted to GenBank. We identified the full-length genomes of ten TSWV isolates, infecting tobacco plants from various regions of China. Besides these, six isolates were partially sequenced. Phylogenetic analysis was performed to assess the relativeness of newly identified sequences and corresponding sequences from GenBank. Recombination and population dynamics analysis was performed using RDP4, RAT, and statistical estimation. Reassortment analysis was performed using MegaX software. RESULTS Phylogenetic analysis of 41 newly identified sequences, depicted that the majority of the Chinese isolates have separate placement in the tree. RDP4 software predicted that RNA M of newly reported isolate YNKM-2 had a recombinant region spanning from 3111 to 3811 bp. The indication of parental sequences (YNKMXD and YNHHKY) from newly identified isolates, revealed the conservation of local TSWV population. Genetic diversity and population dynamics analysis also support the same trend. RNA M was highlighted to be more capable of mutating or evolving as revealed by data obtained from RDP4, RAT, population dynamics, and phylogenetic analyses. Reassortment analysis revealed that it might have happened in L segment of TSWV isolate YNKMXD (reported herein). CONCLUSION Taken together, this is the first detailed study revealing the pattern of TWSV genetic diversity, and population dynamics helping to better understand the ability of this pathogen to drastically reduce the tobacco production in China. Also, this is a valuable addition to the existing worldwide profile of TSWV, especially in China, where a few studies related to TSWV have been reported including only one complete genome of this virus isolated from tobacco plants.
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Affiliation(s)
- Ali Kamran
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China
- Graduate School of Chinese Academy of Agricultural Sciences, 100081, Beijing, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, 550025, Guiyang, China
| | - Ying Li
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China
| | - Wanhong Zhang
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China
| | - Yubin Jiao
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China
| | - Tahir Farooq
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, 510640, Guangzhou, China
| | - Yong Wang
- Tobacco Company of Yunnan Province, Liangshan Company, 615000, Xichang, Sichuan, China
| | - Dongyang Liu
- Tobacco Company of Yunnan Province, Liangshan Company, 615000, Xichang, Sichuan, China
| | - Lianqiang Jiang
- Tobacco Company of Yunnan Province, Liangshan Company, 615000, Xichang, Sichuan, China
| | - Lili Shen
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China
| | - Fenglong Wang
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China.
| | - Jinguang Yang
- Key Laboratory of Tobacco Pest Monitoring, Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 266101, Qingdao, China.
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Gong X, Hu M, Chen W, Yang H, Wang B, Yue J, Jin Y, Liang L, Ren H. Reassortment Network of Influenza A Virus. Front Microbiol 2021; 12:793500. [PMID: 34975817 PMCID: PMC8716808 DOI: 10.3389/fmicb.2021.793500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Influenza A virus (IAV) genomes are composed of eight single-stranded RNA segments. Genetic exchange through reassortment of the segmented genomes often endows IAVs with new genetic characteristics, which may affect transmissibility and pathogenicity of the viruses. However, a comprehensive understanding of the reassortment history of IAVs remains lacking. To this end, we assembled 40,296 whole-genome sequences of IAVs for analysis. Using a new clustering method based on Mean Pairwise Distances in the phylogenetic trees, we classified each segment of IAVs into clades. Correspondingly, reassortment events among IAVs were detected by checking the segment clade compositions of related genomes under specific environment factors and time period. We systematically identified 1,927 possible reassortment events of IAVs and constructed their reassortment network. Interestingly, minimum spanning tree of the reassortment network reproved that swine act as an intermediate host in the reassortment history of IAVs between avian species and humans. Moreover, reassortment patterns among related subtypes constructed in this study are consistent with previous studies. Taken together, our genome-wide reassortment analysis of all the IAVs offers an overview of the leaping evolution of the virus and a comprehensive network representing the relationships of IAVs.
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Affiliation(s)
- Xingfei Gong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
- College of Computer, National University of Defense Technology, Changsha, China
| | - Mingda Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Wei Chen
- College of Computer, National University of Defense Technology, Changsha, China
| | - Haoyi Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
- College of Computer, National University of Defense Technology, Changsha, China
| | - Boqian Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Yue
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Yuan Jin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
- Yuan Jin,
| | - Long Liang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
- Long Liang,
| | - Hongguang Ren
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
- *Correspondence: Hongguang Ren,
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Ding X, Qin L, Meng J, Peng Y, Wu A, Jiang T. Progress and Challenge in Computational Identification of Influenza Virus Reassortment. Virol Sin 2021; 36:1273-1283. [PMID: 34037948 DOI: 10.1007/s12250-021-00392-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/29/2021] [Indexed: 12/22/2022] Open
Abstract
Genomic reassortment is an important evolutionary mechanism for influenza viruses. In this process, the novel viruses acquire new characteristics by the exchange of the intact gene segments among multiple influenza virus genomes, which may cause flu endemics and epidemics within or even across hosts. Due to the safety and ethical limitations of the experimental studies on influenza virus reassortment, numerous computational researches on the influenza virus reassortment have been done with the explosion of the influenza virus genomic data. A great amount of computational methods and bioinformatics databases were developed to facilitate the identification of influenza virus reassortments. In this review, we summarized the progress and challenge of the bioinformatics research on influenza virus reassortment, which can guide the researchers to investigate the influenza virus reassortment events reasonably and provide valuable insight to develop the related computational identification tools.
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Affiliation(s)
- Xiao Ding
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.,Suzhou Institute of Systems Medicine, Suzhou, Jiangsu, 215123, China
| | - Luyao Qin
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.,Suzhou Institute of Systems Medicine, Suzhou, Jiangsu, 215123, China
| | - Jing Meng
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.,Suzhou Institute of Systems Medicine, Suzhou, Jiangsu, 215123, China
| | - Yousong Peng
- College of Biology, Hunan Provincial Key Laboratory of Medical Virology, Hunan University, Changsha, 410082, China
| | - Aiping Wu
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.,Suzhou Institute of Systems Medicine, Suzhou, Jiangsu, 215123, China
| | - Taijiao Jiang
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China. .,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, 510005, China. .,Suzhou Institute of Systems Medicine, Suzhou, Jiangsu, 215123, China.
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4
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Effect of N-linked glycosylation at position 162 of hemagglutinin in influenza A virus A(H1N1)pdm09. Meta Gene 2021. [DOI: 10.1016/j.mgene.2020.100828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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5
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Chaput DL, Bass D, Alam MM, Al Hasan N, Stentiford GD, van Aerle R, Moore K, Bignell JP, Haque MM, Tyler CR. The Segment Matters: Probable Reassortment of Tilapia Lake Virus (TiLV) Complicates Phylogenetic Analysis and Inference of Geographical Origin of New Isolate from Bangladesh. Viruses 2020; 12:v12030258. [PMID: 32120863 PMCID: PMC7150994 DOI: 10.3390/v12030258] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/26/2022] Open
Abstract
Tilapia lake virus (TiLV), a negative sense RNA virus with a 10 segment genome, is an emerging threat to tilapia aquaculture worldwide, with outbreaks causing over 90% mortality reported on several continents since 2014. Following a severe tilapia mortality event in July 2017, we confirmed the presence of TiLV in Bangladesh and obtained the near-complete genome of this isolate, BD-2017. Phylogenetic analysis of the concatenated 10 segment coding regions placed BD-2017 in a clade with the two isolates from Thailand, separate from the Israeli and South American isolates. However, phylogenetic analysis of individual segments gave conflicting results, sometimes clustering BD-2017 with one of the Israeli isolates, and splitting pairs of isolates from the same region. By comparing patterns of topological difference among segments of quartets of isolates, we showed that TiLV likely has a history of reassortment. Segments 5 and 6, in particular, appear to have undergone a relatively recent reassortment event involving Ecuador isolate EC-2012 and Israel isolate Til-4-2011. The phylogeny of TiLV isolates therefore depends on the segment sequenced. Our findings illustrate the need to exercise caution when using phylogenetic analysis to infer geographic origin and track the movement of TiLV, and we recommend using whole genomes wherever possible.
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Affiliation(s)
- Dominique L. Chaput
- Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, Devon EX4 4QD, UK
- Correspondence: (D.L.C.); (C.R.T.); Tel.: +44-(0)-1392-724450 (C.R.T.)
| | - David Bass
- Centre for Sustainable Aquaculture Futures, University of Exeter, Exeter, Devon EX4 4QD, UK; (D.B.); (G.D.S.); (R.v.A.)
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset DT4 8UB, UK;
| | - Md. Mehedi Alam
- Department of Aquaculture, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh; (M.M.A.); (N.A.H.); (M.M.H.)
| | - Neaz Al Hasan
- Department of Aquaculture, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh; (M.M.A.); (N.A.H.); (M.M.H.)
| | - Grant D. Stentiford
- Centre for Sustainable Aquaculture Futures, University of Exeter, Exeter, Devon EX4 4QD, UK; (D.B.); (G.D.S.); (R.v.A.)
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset DT4 8UB, UK;
| | - Ronny van Aerle
- Centre for Sustainable Aquaculture Futures, University of Exeter, Exeter, Devon EX4 4QD, UK; (D.B.); (G.D.S.); (R.v.A.)
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset DT4 8UB, UK;
| | - Karen Moore
- Exeter Sequencing Service, Geoffrey Pope Building, University of Exeter, Exeter, Devon EX4 4QD, UK;
| | - John P. Bignell
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset DT4 8UB, UK;
| | - Mohammad Mahfujul Haque
- Department of Aquaculture, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh; (M.M.A.); (N.A.H.); (M.M.H.)
| | - Charles R. Tyler
- Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, Devon EX4 4QD, UK
- Centre for Sustainable Aquaculture Futures, University of Exeter, Exeter, Devon EX4 4QD, UK; (D.B.); (G.D.S.); (R.v.A.)
- Correspondence: (D.L.C.); (C.R.T.); Tel.: +44-(0)-1392-724450 (C.R.T.)
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6
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Sequence analysis of the medium and small RNAs of impatiens necrotic spot virus reveals segment reassortment but not recombination. Arch Virol 2019; 164:2829-2836. [PMID: 31486908 DOI: 10.1007/s00705-019-04389-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 07/31/2019] [Indexed: 02/05/2023]
Abstract
The complete sequence of the medium (M) and small (S) RNA genome segments were determined for twelve isolates of impatiens necrotic spot virus from eight plant species. The M- and S-RNAs of these isolates shared 97-99% and 93-98% nucleotide sequence identity, respectively, with the corresponding full-length sequences available in public databases. Phylogenetic analysis based on the M- or S-RNA sequences showed incongruence in the phylogenetic position of some isolates, suggesting intraspecies segment reassortment. The lack of phylogenetic discordance in individual and concatenated sequences of individual genes encoded by M- or S-RNAs suggests that segment reassortment rather than recombination is driving evolution of these INSV isolates.
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7
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Fitness cost of reassortment in human influenza. PLoS Pathog 2017; 13:e1006685. [PMID: 29112968 PMCID: PMC5675378 DOI: 10.1371/journal.ppat.1006685] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 10/09/2017] [Indexed: 12/15/2022] Open
Abstract
Reassortment, which is the exchange of genome sequence between viruses co-infecting a host cell, plays an important role in the evolution of segmented viruses. In the human influenza virus, reassortment happens most frequently between co-existing variants within the same lineage. This process breaks genetic linkage and fitness correlations between viral genome segments, but the resulting net effect on viral fitness has remained unclear. In this paper, we determine rate and average selective effect of reassortment processes in the human influenza lineage A/H3N2. For the surface proteins hemagglutinin and neuraminidase, reassortant variants with a mean distance of at least 3 nucleotides to their parent strains get established at a rate of about 10−2 in units of the neutral point mutation rate. Our inference is based on a new method to map reassortment events from joint genealogies of multiple genome segments, which is tested by extensive simulations. We show that intra-lineage reassortment processes are, on average, under substantial negative selection that increases in strength with increasing sequence distance between the parent strains. The deleterious effects of reassortment manifest themselves in two ways: there are fewer reassortment events than expected from a null model of neutral reassortment, and reassortant strains have fewer descendants than their non-reassortant counterparts. Our results suggest that influenza evolves under ubiquitous epistasis across proteins, which produces fitness barriers against reassortment even between co-circulating strains within one lineage. The genome of the human influenza virus consists of 8 disjoint RNA polymer segments. These segments can undergo reassortment: when two viruses co-infect a host cell, they can produce viral offspring with a new combination of segments. In this paper, we show that reassortment within a given influenza lineage induces a fitness cost that increases in strength with increasing genetic distance of the parent viruses. Our finding suggests that evolution continuously produces viral proteins whose fitness depends on each other; reassortment reduces fitness by breaking up successful combinations of proteins. Thus, selection across proteins constrains viral evolution within a given lineage, and it may be an important factor in defining a viral species.
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8
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Vijaykrishna D, Mukerji R, Smith GJD. RNA Virus Reassortment: An Evolutionary Mechanism for Host Jumps and Immune Evasion. PLoS Pathog 2015; 11:e1004902. [PMID: 26158697 PMCID: PMC4497687 DOI: 10.1371/journal.ppat.1004902] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Dhanasekaran Vijaykrishna
- Duke-NUS Graduate Medical School, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Pathology, Singapore General Hospital, SingHealth, Singapore
- * E-mail:
| | | | - Gavin J. D. Smith
- Duke-NUS Graduate Medical School, Singapore
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
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9
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Neverov AD, Lezhnina KV, Kondrashov AS, Bazykin GA. Intrasubtype reassortments cause adaptive amino acid replacements in H3N2 influenza genes. PLoS Genet 2014; 10:e1004037. [PMID: 24415946 PMCID: PMC3886890 DOI: 10.1371/journal.pgen.1004037] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 11/01/2013] [Indexed: 01/15/2023] Open
Abstract
Reassortments and point mutations are two major contributors to diversity of Influenza A virus; however, the link between these two processes is unclear. It has been suggested that reassortments provoke a temporary increase in the rate of amino acid changes as the viral proteins adapt to new genetic environment, but this phenomenon has not been studied systematically. Here, we use a phylogenetic approach to infer the reassortment events between the 8 segments of influenza A H3N2 virus since its emergence in humans in 1968. We then study the amino acid replacements that occurred in genes encoded in each segment subsequent to reassortments. In five out of eight genes (NA, M1, HA, PB1 and NS1), the reassortment events led to a transient increase in the rate of amino acid replacements on the descendant phylogenetic branches. In NA and HA, the replacements following reassortments were enriched with parallel and/or reversing replacements; in contrast, the replacements at sites responsible for differences between antigenic clusters (in HA) and at sites under positive selection (in NA) were underrepresented among them. Post-reassortment adaptive walks contribute to adaptive evolution in Influenza A: in NA, an average reassortment event causes at least 2.1 amino acid replacements in a reassorted gene, with, on average, 0.43 amino acid replacements per evolving post-reassortment lineage; and at least ~9% of all amino acid replacements are provoked by reassortments.
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Affiliation(s)
- Alexey D. Neverov
- Federal Budget Institution of Science “Central Research Institute for Epidemiology”, Moscow, Russia
- Department of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Ksenia V. Lezhnina
- Department of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Alexey S. Kondrashov
- Department of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
- Life Sciences Institute and Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Georgii A. Bazykin
- Department of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
- Institute for Information Transmission Problems of the Russian Academy of Sciences (Kharkevich Institute), Moscow, Russia
- * E-mail:
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10
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Critical role of segment-specific packaging signals in genetic reassortment of influenza A viruses. Proc Natl Acad Sci U S A 2013; 110:E3840-8. [PMID: 24043788 DOI: 10.1073/pnas.1308649110] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The fragmented nature of the influenza A genome allows the exchange of gene segments when two or more influenza viruses infect the same cell, but little is known about the rules underlying this process. Here, we studied genetic reassortment between the A/Moscow/10/99 (H3N2, MO) virus originally isolated from human and the avian A/Finch/England/2051/91 (H5N2, EN) virus and found that this process is strongly biased. Importantly, the avian HA segment never entered the MO genetic background alone but always was accompanied by the avian PA and M fragments. Introduction of the 5' and 3' packaging sequences of HA(MO) into an otherwise HA(EN) backbone allowed efficient incorporation of the chimerical viral RNA (vRNA) into the MO genetic background. Furthermore, forcing the incorporation of the avian M segment or introducing five silent mutations into the human M segment was sufficient to drive coincorporation of the avian HA segment into the MO genetic background. These silent mutations also strongly affected the genotype of reassortant viruses. Taken together, our results indicate that packaging signals are crucial for genetic reassortment and that suboptimal compatibility between the vRNA packaging signals, which are detected only when vRNAs compete for packaging, limit this process.
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11
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Svinti V, Cotton JA, McInerney JO. New approaches for unravelling reassortment pathways. BMC Evol Biol 2013; 13:1. [PMID: 23279962 PMCID: PMC3541980 DOI: 10.1186/1471-2148-13-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 11/21/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Every year the human population encounters epidemic outbreaks of influenza, and history reveals recurring pandemics that have had devastating consequences. The current work focuses on the development of a robust algorithm for detecting influenza strains that have a composite genomic architecture. These influenza subtypes can be generated through a reassortment process, whereby a virus can inherit gene segments from two different types of influenza particles during replication. Reassortant strains are often not immediately recognised by the adaptive immune system of the hosts and hence may be the source of pandemic outbreaks. Owing to their importance in public health and their infectious ability, it is essential to identify reassortant influenza strains in order to understand the evolution of this virus and describe reassortment pathways that may be biased towards particular viral segments. Phylogenetic methods have been used traditionally to identify reassortant viruses. In many studies up to now, the assumption has been that if two phylogenetic trees differ, it is because reassortment has caused them to be different. While phylogenetic incongruence may be caused by real differences in evolutionary history, it can also be the result of phylogenetic error. Therefore, we wish to develop a method for distinguishing between topological inconsistency that is due to confounding effects and topological inconsistency that is due to reassortment. RESULTS The current work describes the implementation of two approaches for robustly identifying reassortment events. The algorithms rest on the idea of significance of difference between phylogenetic trees or phylogenetic tree sets, and subtree pruning and regrafting operations, which mimic the effect of reassortment on tree topologies. The first method is based on a maximum likelihood (ML) framework (MLreassort) and the second implements a Bayesian approach (Breassort) for reassortment detection. We focus on reassortment events that are found by both methods. We test both methods on a simulated dataset and on a small collection of real viral data isolated in Hong Kong in 1999. CONCLUSIONS The nature of segmented viral genomes present many challenges with respect to disease. The algorithms developed here can effectively identify reassortment events in small viral datasets and can be applied not only to influenza but also to other segmented viruses. Owing to computational demands of comparing tree topologies, further development in this area is necessary to allow their application to larger datasets.
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Affiliation(s)
- Victoria Svinti
- Department of Biology, National University of Ireland at Maynooth, Maynooth, Co Kildare, Ireland
- Current address: Department of Microbiology & Immunology, Life Sciences Centre, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - James A Cotton
- Department of Biology, National University of Ireland at Maynooth, Maynooth, Co Kildare, Ireland
- Current address: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - James O McInerney
- Department of Biology, National University of Ireland at Maynooth, Maynooth, Co Kildare, Ireland
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12
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Suzuki Y, Kobayashi Y. Evolution of complementary nucleotides in 5' and 3' untranslated regions of influenza A virus genomic segments. INFECTION GENETICS AND EVOLUTION 2012; 13:175-9. [PMID: 23146832 DOI: 10.1016/j.meegid.2012.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/29/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022]
Abstract
The genome of influenza A virus comprises 8 segments (segments 1-8) of single-stranded RNA (virion RNA: vRNA) with negative-polarity. All vRNAs share 13 and 12 terminal nucleotides in the 5' and 3' untranslated regions (UTRs), respectively, which are partially complementary and constitute panhandle and corkscrew structures. Here, it is shown, from the analysis of genomic sequences for 506 strains of influenza A virus, that the number of contiguous complementary nucleotides in the 5' and 3' UTRs varies from 4 to 7 among segments. Complementary nucleotides were segment specific and highly conserved in all segments except for segment 6, where in the phylogenetic analysis co-evolution was observed to have occurred between and within subtypes of neuraminidase (NA). Mutations in the terminal sequences sometimes appeared to have caused convergence between subtypes, involving changes in multiple nucleotide positions. These observations suggest that intra-segmental (homologous) recombinations may have taken place for transferring terminal sequences in segment 6.
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Affiliation(s)
- Yoshiyuki Suzuki
- Graduate School of Natural Sciences, Nagoya City University, 1 Yamanohata, Nagoya-shi, Aichi-ken 467-8501, Japan.
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13
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Lun AT, Wong JW, Downard KM. FluShuffle and FluResort: new algorithms to identify reassorted strains of the influenza virus by mass spectrometry. BMC Bioinformatics 2012; 13:208. [PMID: 22906155 PMCID: PMC3505172 DOI: 10.1186/1471-2105-13-208] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/10/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Influenza is one of the oldest and deadliest infectious diseases known to man. Reassorted strains of the virus pose the greatest risk to both human and animal health and have been associated with all pandemics of the past century, with the possible exception of the 1918 pandemic, resulting in tens of millions of deaths. We have developed and tested new computer algorithms, FluShuffle and FluResort, which enable reassorted viruses to be identified by the most rapid and direct means possible. These algorithms enable reassorted influenza, and other, viruses to be rapidly identified to allow prevention strategies and treatments to be more efficiently implemented. RESULTS The FluShuffle and FluResort algorithms were tested with both experimental and simulated mass spectra of whole virus digests. FluShuffle considers different combinations of viral protein identities that match the mass spectral data using a Gibbs sampling algorithm employing a mixed protein Markov chain Monte Carlo (MCMC) method. FluResort utilizes those identities to calculate the weighted distance of each across two or more different phylogenetic trees constructed through viral protein sequence alignments. Each weighted mean distance value is normalized by conversion to a Z-score to establish a reassorted strain. CONCLUSIONS The new FluShuffle and FluResort algorithms can correctly identify the origins of influenza viral proteins and the number of reassortment events required to produce the strains from the high resolution mass spectral data of whole virus proteolytic digestions. This has been demonstrated in the case of constructed vaccine strains as well as common human seasonal strains of the virus. The algorithms significantly improve the capability of the proteotyping approach to identify reassorted viruses that pose the greatest pandemic risk.
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Affiliation(s)
- Aaron Tl Lun
- School of Molecular Bioscience G-08, The University of Sydney, Sydney, NSW, 2006, Australia
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Lei F, Shi W. Prospective of Genomics in Revealing Transmission, Reassortment and Evolution of Wildlife-Borne Avian Influenza A (H5N1) Viruses. Curr Genomics 2011; 12:466-74. [PMID: 22547954 PMCID: PMC3219842 DOI: 10.2174/138920211797904052] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 07/27/2011] [Accepted: 08/10/2011] [Indexed: 12/24/2022] Open
Abstract
The outbreak of highly pathogenic avian influenza (HPAI) H5N1 disease has led to significant loss of poultry and wild life and case fatality rates in humans of 60%. Wild birds are natural hosts for all avian influenza virus subtypes and over120 bird species have been reported with evidence of H5N1 infection. Influenza A viruses possess a segmented RNA genome and are characterized by frequently occurring genetic reassortment events, which play a very important role in virus evolution and the spread of novel gene constellations in immunologically naïve human and animal populations. Phylogenetic analysis of whole genome or sub-genomic sequences is a standard means for delineating genetic variation, novel reassortment events, and surveillance to trace the global transmission pathways. In this paper, special emphasis is given to the transmission and circulation of H5N1 among wild life populations, and to the reassortment events that are associated with inter-host transmission of the H5N1 viruses when they infect different hosts, such as birds, pigs and humans. In addition, we review the inter-subtype reassortment of the viral segments encoding inner proteins between the H5N1 viruses and viruses of other subtypes, such as H9N2 and H6N1. Finally, we highlight the usefulness of genomic sequences in molecular epidemiological analysis of HPAI H5N1 and the technical limitations in existing analytical methods that hinder them from playing a greater role in virological research.
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Affiliation(s)
- Fumin Lei
- Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weifeng Shi
- The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Increased pathogenicity of a reassortant 2009 pandemic H1N1 influenza virus containing an H5N1 hemagglutinin. J Virol 2011; 85:12262-70. [PMID: 21917948 DOI: 10.1128/jvi.05582-11] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A novel H1N1 influenza virus emerged in 2009 (pH1N1) to become the first influenza pandemic of the 21st century. This virus is now cocirculating with highly pathogenic H5N1 avian influenza viruses in many parts of the world, raising concerns that a reassortment event may lead to highly pathogenic influenza strains with the capacity to infect humans more readily and cause severe disease. To investigate the virulence of pH1N1-H5N1 reassortant viruses, we created pH1N1 (A/California/04/2009) viruses expressing individual genes from an avian H5N1 influenza strain (A/Hong Kong/483/1997). Using several in vitro models of virus replication, we observed increased replication for a reassortant CA/09 virus expressing the hemagglutinin (HA) gene of HK/483 (CA/09-483HA) relative to that of either parental CA/09 virus or reassortant CA/09 expressing other HK/483 genes. This increased replication correlated with enhanced pathogenicity in infected mice similar to that of the parental HK/483 strain. The serial passage of the CA/09 parental virus and the CA/09-483HA virus through primary human lung epithelial cells resulted in increased pathogenicity, suggesting that these viruses easily adapt to humans and become more virulent. In contrast, serial passage attenuated the parental HK/483 virus in vitro and resulted in slightly reduced morbidity in vivo, suggesting that sustained replication in humans attenuates H5N1 avian influenza viruses. Taken together, these data suggest that reassortment between cocirculating human pH1N1 and avian H5N1 influenza strains will result in a virus with the potential for increased pathogenicity in mammals.
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Molecular and genetic analysis of NS gene from high pathogenic strains of the avian influenza (H5N1) virus isolated in Kazakhstan. Gene 2011; 476:15-9. [PMID: 21338659 DOI: 10.1016/j.gene.2011.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 02/05/2011] [Accepted: 02/13/2011] [Indexed: 11/21/2022]
Abstract
The high pathogenic strains of the avian influenza H5N1 virus isolated in Kazakhstan have NS of different genotypes. The influenza virus strains isolated in 2005 is of NS1E Qinghai genotype. A/swan/Mangystau/3/2006 strain is of NS2A genotype that is typical for Gs/Gd-like strains. The results of the analysis allow assuming that A/swan/Mangystau/3/2006 strain has been brought onto the territory of Kazakhstan from the European part of the continent along the Black Sea-Mediterranean flyway.
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