scholarly journals Viral Metagenomics Revealed Sendai Virus and Coronavirus Infection of Malayan Pangolins (Manis javanica)

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 979 ◽  
Author(s):  
Ping Liu ◽  
Wu Chen ◽  
Jin-Ping Chen
Keyword(s):  
De Novo ◽  
Sendai Virus ◽  
Sequence Similarity ◽  
Viral Metagenomics ◽  
Manis Javanica ◽  
Pathogenic Viruses ◽  
Viral Communities ◽  
High Level ◽  
Viral Sequences ◽  
Insight Into

Pangolins are endangered animals in urgent need of protection. Identifying and cataloguing the viruses carried by pangolins is a logical approach to evaluate the range of potential pathogens and help with conservation. This study provides insight into viral communities of Malayan Pangolins (Manis javanica) as well as the molecular epidemiology of dominant pathogenic viruses between Malayan Pangolin and other hosts. A total of 62,508 de novo assembled contigs were constructed, and a BLAST search revealed 3600 ones (≥300 nt) were related to viral sequences, of which 68 contigs had a high level of sequence similarity to known viruses, while dominant viruses were the Sendai virus and Coronavirus. This is the first report on the viral diversity of pangolins, expanding our understanding of the virome in endangered species, and providing insight into the overall diversity of viruses that may be capable of directly or indirectly crossing over into other mammals.

scholarly journals Initial virome characterization of the common cnidarian lab model Nematostella vectensis

2020 ◽  
Author(s):  
Magda Lewandowska ◽  
Yael Hazan ◽  
Yehu Moran
Keyword(s):  
Developmental Stages ◽  
De Novo ◽  
Artemia Salina ◽  
Model Organisms ◽  
Nematostella Vectensis ◽  
Virus Identification ◽  
Functional Studies ◽  
Powerful Approach ◽  
Viral Communities ◽  
Viral Sequences

AbstractThe role of viruses in forming a stable holobiont has been a subject of extensive research in the recent years. However, many emerging model organisms still lack any data on the composition of the associated viral communities. Here, we re-analyzed seven publicly available transcriptome datasets of the starlet sea anemone Nematostella vectensis, the most commonly used anthozoan lab model, and searched for viral sequences. We applied a straightforward, yet powerful approach of de novo assembly followed by homology-based virus identification and a multi-step, thorough taxonomic validation. The comparison of different lab populations of N. vectensis revealed the existence of the core virome composed of 21 viral sequences, present in all adult datasets. Unexpectedly, we observed almost complete lack of viruses in the samples from the early developmental stages which together with the identification of the viruses shared with the major source of the food in the lab, the brine shrimp Artemia salina, shed new light on the course of viral species acquisition in N. vectensis. Our study provides an initial, yet comprehensive insight into N. vectensis virome and sets the first foundation for functional studies of viruses and antiviral systems in this lab model cnidarian.

scholarly journals Comprehensive discovery of CRISPR-targeted terminally redundant sequences in the human gut metagenome: Viruses, plasmids, and more

2021 ◽  
Vol 17 (10) ◽  
pp. e1009428
Author(s):  
Ryota Sugimoto ◽  
Luca Nishimura ◽  
Phuong Thanh Nguyen ◽  
Jumpei Ito ◽  
Nicholas F. Parrish ◽  
...  
Keyword(s):  
De Novo ◽  
Sequence Similarity ◽  
Metagenomic Data ◽  
Marker Genes ◽  
Biological Entity ◽  
Metagenomic Sequencing ◽  
Sequencing Data ◽  
Human Gut ◽  
Protein Coding ◽  
Viral Sequences

Viruses are the most numerous biological entity, existing in all environments and infecting all cellular organisms. Compared with cellular life, the evolution and origin of viruses are poorly understood; viruses are enormously diverse, and most lack sequence similarity to cellular genes. To uncover viral sequences without relying on either reference viral sequences from databases or marker genes that characterize specific viral taxa, we developed an analysis pipeline for virus inference based on clustered regularly interspaced short palindromic repeats (CRISPR). CRISPR is a prokaryotic nucleic acid restriction system that stores the memory of previous exposure. Our protocol can infer CRISPR-targeted sequences, including viruses, plasmids, and previously uncharacterized elements, and predict their hosts using unassembled short-read metagenomic sequencing data. By analyzing human gut metagenomic data, we extracted 11,391 terminally redundant CRISPR-targeted sequences, which are likely complete circular genomes. The sequences included 2,154 tailed-phage genomes, together with 257 complete crAssphage genomes, 11 genomes larger than 200 kilobases, 766 genomes of Microviridae species, 56 genomes of Inoviridae species, and 95 previously uncharacterized circular small genomes that have no reliably predicted protein-coding gene. We predicted the host(s) of approximately 70% of the discovered genomes at the taxonomic level of phylum by linking protospacers to taxonomically assigned CRISPR direct repeats. These results demonstrate that our protocol is efficient for de novo inference of CRISPR-targeted sequences and their host prediction.

scholarly journals Initial Virome Characterization of the Common Cnidarian Lab Model Nematostella vectensis

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 218
Author(s):  
Magda Lewandowska ◽  
Yael Hazan ◽  
Yehu Moran
Keyword(s):  
Developmental Stages ◽  
De Novo ◽  
Artemia Salina ◽  
Model Organisms ◽  
Nematostella Vectensis ◽  
Virus Identification ◽  
Functional Studies ◽  
Powerful Approach ◽  
Viral Communities ◽  
Viral Sequences

The role of viruses in forming a stable holobiont has been the subject of extensive research in recent years. However, many emerging model organisms still lack any data on the composition of the associated viral communities. Here, we re-analyzed seven publicly available transcriptome datasets of the starlet sea anemone Nematostella vectensis, the most commonly used anthozoan lab model, and searched for viral sequences. We applied a straightforward, yet powerful approach of de novo assembly followed by homology-based virus identification and a multi-step, thorough taxonomic validation. The comparison of different lab populations of N. vectensis revealed the existence of the core virome composed of 21 viral sequences, present in all adult datasets. Unexpectedly, we observed an almost complete lack of viruses in the samples from the early developmental stages, which together with the identification of the viruses shared with the major source of the food in the lab, the brine shrimp Artemia salina, shed new light on the course of viral species acquisition in N. vectensis. Our study provides an initial, yet comprehensive insight into N. vectensis virome and sets the first foundation for the functional studies of viruses and antiviral systems in this lab model cnidarian.

scholarly journals Temporal Patterns of Bacterial and Viral Communities during Algae Blooms of a Reservoir in Macau

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 894
Author(s):  
Dini Hu ◽  
John P. Giesy ◽  
Min Guo ◽  
Wai Kin Ung ◽  
Yijun Kong ◽  
...  
Keyword(s):  
16S Rrna ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
Viral Metagenomics ◽  
Principal Coordinates Analysis ◽  
Algae Blooms ◽  
Principal Coordinates ◽  
Viral Communities ◽  
Insight Into ◽  
Generation Sequencing

Compositions of microbial communities associated with blooms of algae in a storage reservoir in Macau, China were investigated between 2013 and 2016. Algae were enumerated by visible light microscopy. Profiles of organisms in water were examined by 16S rRNA sequences and viral metagenomics, based on next generation sequencing. Results of 16S rRNA sequencing indicated that majority of the identified organisms were bacteria closely related to Proteobacteria, Cyanobacteria, Verrucomicrobia, Bacteroidetes, and Actinobacteria. Metagenomics sequences demonstrated that the dominant virus was Phycodnavirus, accounting for 70% of the total population. Patterns of relative numbers of bacteria in the microbial community and their temporal changes were determined through alpha diversity indices, principal coordinates analysis (PCoA), relative abundance, and visualized by Venn diagrams. Ways in which the bacterial and viral communities are influenced by various water-related variables were elucidated based on redundancy analysis (RDA). Relationships of the relative numbers of bacteria with trophic status in a reservoir used for drinking water in Macau, provided insight into associations of Phycodnavirus and Proteobacteria with changes in blooms of algae.

scholarly journals The Use of Informativity in the Development of Robust Metaviromics-based Examinations

2016 ◽  
Author(s):  
Siobhan C. Watkins ◽  
Thomas Hatzopoulos ◽  
Catherine Putonti
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Information Content ◽  
Sequence Similarity ◽  
Phylogenetic Signal ◽  
Viral Metagenomics ◽  
Proof Of Concept ◽  
Sequence Identity ◽  
Genomic Approach ◽  
Insight Into

AbstractThe field of metagenomics has developed insight into many of the complex microbial communities responsible for maintaining life on this planet. Sequencing efforts often uncover novel genetic content; this is most evident for viral metagenomics, in which upwards of 90% of all sequences demonstrate no sequence similarity with present databases. For the small fraction which can be identified, the top BLAST hit is often posited as being representative of the phage taxon. However, as previous research has shown, the top BLAST hit is sometimes misinterpreted. Furthermore, the appearance of a particular gene homolog is frequently not representative of the presence of the particular taxon in question. To circumvent these limitations, we have developed a new method for the analysis of metaviromic datasets. BLAST hits are weighted, integrating the sequence identity and length of alignments as well as a phylogenetic signal. A genic rather than genomic approach is presented in which each gene is evaluated with respect to its information content. Through this quantifiable metric, predictions of viral community structure can be made with greater confidence. As a proof-of-concept, the approach presented here was implemented and applied to seven metaviromes. While providing a more robust means of evaluating metaviromic data, the tool is versatile and can easily be customized to investigations of any environment or biome.

scholarly journals VIGA: a sensitive, precise and automatic de novo VIral Genome Annotator

2018 ◽  
Author(s):  
Enrique González-Tortuero ◽  
Thomas David Sean Sutton ◽  
Vimalkumar Velayudhan ◽  
Andrey Nikolaevich Shkoporov ◽  
Lorraine Anne Draper ◽  
...  
Keyword(s):  
Genome Annotation ◽  
Viral Genome ◽  
De Novo ◽  
Lower Number ◽  
Viral Metagenomics ◽  
Viral Genomes ◽  
Genomic Studies ◽  
Bioinformatic Approaches ◽  
Viral Sequences

AbstractViral (meta)genomics is a rapidly growing field of study that is hampered by an inability to annotate the majority of viral sequences; therefore, the development of new bioinformatic approaches is very important. Here, we present a new automatic de novo genome annotation pipeline, called VIGA, to annotate prokaryotic and eukaryotic viral sequences from (meta)genomic studies. VIGA was benchmarked on a database of known viral genomes and a viral metagenomics case study. VIGA generated the most accurate outputs according to the number of coding sequences and their coordinates, outputs also had a lower number of non-informative annotations compared to other programs.

scholarly journals Close relationship between coral-associated Chromera strains despite major differences within the Symbiodiniaceae

2019 ◽  
Author(s):  
Amin R. Mohamed ◽  
Cheong Xin Chan ◽  
Mark A. Ragan ◽  
Jia Zhang ◽  
Ira Cooke ◽  
...  
Keyword(s):  
Reference Strain ◽  
De Novo ◽  
Sequence Similarity ◽  
Temperature Tolerance ◽  
Coral Host ◽  
Reef Corals ◽  
Close Relationship ◽  
Mutualistic Relationship ◽  
Low Levels ◽  
High Level

SummaryReef-building corals live in a mutualistic relationship with photosynthetic algae (family Symbiodiniaceae) that usually provide most of the energy required by the coral host. This relationship is sensitive to temperature stress; as little as a 1°C increase often leading to collapse of the association. This sensitivity has led to interest in the potential of more stress tolerant algae to supplement or substitute for the normal Symbiodiniaceae mutualists. In this respect, the apicomplexan-like microalga Chromera is of particular interest due to its greater temperature tolerance. We generated a de novo transcriptome for a Chromera strain isolated from a GBR coral (“GBR Chromera”) and compared to those of the reference strain of Chromera (“Sydney Chromera”), and to those of Symbiodiniaceae (Fugacium, Cladocopium and Breviolum), as well as the apicomplexan parasite, Plasmodium falciparum. By contrast with the Symbiodiniaceae, the two Chromera strains had a high level of sequence similarity evident by very low levels of divergence in orthologous genes. Although KEGG categories provide few criteria by which true coral mutualists might be identified, they do supply a molecular rationalization for the ubiquitous association of Cladocopium strains with Indo-Pacific reef corals. The presence of HSP20 genes may underlie the higher thermal tolerance of Chromera.

scholarly journals De novo virus inference and host prediction from metagenome using CRISPR spacers

2020 ◽  
Author(s):  
Ryota Sugimoto ◽  
Luca Nishimura ◽  
Phuong Nguyen Thanh ◽  
Jumpei Ito ◽  
Nicholas F. Parrish ◽  
...  
Keyword(s):  
De Novo ◽  
Sequence Similarity ◽  
Metagenomic Data ◽  
Marker Genes ◽  
Biological Entity ◽  
Metagenomic Sequencing ◽  
Sequencing Data ◽  
Human Gut ◽  
Cellular Genes ◽  
Viral Sequences

AbstractViruses are the most numerous biological entity, existing in all environments and infecting all cellular organisms. Compared with cellular life, the evolution and origin of viruses are poorly understood; viruses are enormously diverse and most lack sequence similarity to cellular genes. To uncover viral sequences without relying on either reference viral sequences from databases or marker genes known to characterize specific viral taxa, we developed an analysis pipeline for virus inference based on clustered regularly interspaced short palindromic repeats (CRISPR). CRISPR is a prokaryotic nucleic acid restriction system that stores memory of previous exposure. Our protocol can infer viral sequences targeted by CRISPR and predict their hosts using unassembled short-read metagenomic sequencing data. Analysing human gut metagenomic data, we extracted 11,391 terminally redundant CRISPR-targeted sequences which are likely complete circular genomes of viruses or plasmids. The sequences include 257 complete crAssphage family genomes, 11 genomes larger than 200 kilobases, 766 genomes of Microviridae species, 114 genomes of Inoviridae species and many entirely novel genomes of unknown taxa. We predicted the host(s) of approximately 70% of discovered genomes by linking protospacers to taxonomically assigned CRISPR direct repeats. These results support that our protocol is efficient for de novo inference of viral genomes and host prediction. In addition, we investigated the origin of the diversity-generating retroelement (DGR) locus of the crAssphage family. Phylogenetic analysis and gene locus comparisons indicate that DGR is orthologous in human gut crAssphages and shares a common ancestor with baboon-derived crAssphage; however, the locus has likely been lost in multiple lineages recently.

scholarly journals Genomic Characterization Provides an Insight into the Pathogenicity of the Poplar Canker Bacterium Lonsdalea populi

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 246
Author(s):  
Xiaomeng Chen ◽  
Rui Li ◽  
Yonglin Wang ◽  
Aining Li
Keyword(s):  
Genome Sequence ◽  
Extracellular Enzymes ◽  
De Novo ◽  
Whole Genome Sequence ◽  
Hybrid Poplars ◽  
A Genome ◽  
Conserved Genes ◽  
Genomic Characterization ◽  
Molecular Bases ◽  
Insight Into

An emerging poplar canker caused by the gram-negative bacterium, Lonsdalea populi, has led to high mortality of hybrid poplars Populus × euramericana in China and Europe. The molecular bases of pathogenicity and bark adaptation of L. populi have become a focus of recent research. This study revealed the whole genome sequence and identified putative virulence factors of L. populi. A high-quality L. populi genome sequence was assembled de novo, with a genome size of 3,859,707 bp, containing approximately 3434 genes and 107 RNAs (75 tRNA, 22 rRNA, and 10 ncRNA). The L. populi genome contained 380 virulence-associated genes, mainly encoding for adhesion, extracellular enzymes, secretory systems, and two-component transduction systems. The genome had 110 carbohydrate-active enzyme (CAZy)-coding genes and putative secreted proteins. The antibiotic-resistance database annotation listed that L. populi was resistant to penicillin, fluoroquinolone, and kasugamycin. Analysis of comparative genomics found that L. populi exhibited the highest homology with the L. britannica genome and L. populi encompassed 1905 specific genes, 1769 dispensable genes, and 1381 conserved genes, suggesting high evolutionary diversity and genomic plasticity. Moreover, the pan genome analysis revealed that the N-5-1 genome is an open genome. These findings provide important resources for understanding the molecular basis of the pathogenicity and biology of L. populi and the poplar-bacterium interaction.

scholarly journals Genome-Wide Metabolic Reconstruction of the Synthesis of Polyhydroxyalkanoates from Sugars and Fatty Acids by Burkholderia Sensu Lato Species

2021 ◽  
Vol 9 (6) ◽  
pp. 1290
Author(s):  
Natalia Alvarez-Santullano ◽  
Pamela Villegas ◽  
Mario Sepúlveda Mardones ◽  
Roberto E. Durán ◽  
Raúl Donoso ◽  
...  
Keyword(s):  
Fatty Acids ◽  
De Novo ◽  
Reducing Power ◽  
Pentose Phosphate ◽  
Fine Tuning ◽  
Metabolic Reconstruction ◽  
Phylogenetic Groups ◽  
Outlier Group ◽  
Pha Genes ◽  
High Level

Burkholderia sensu lato (s.l.) species have a versatile metabolism. The aims of this review are the genomic reconstruction of the metabolic pathways involved in the synthesis of polyhydroxyalkanoates (PHAs) by Burkholderia s.l. genera, and the characterization of the PHA synthases and the pha genes organization. The reports of the PHA synthesis from different substrates by Burkholderia s.l. strains were reviewed. Genome-guided metabolic reconstruction involving the conversion of sugars and fatty acids into PHAs by 37 Burkholderia s.l. species was performed. Sugars are metabolized via the Entner–Doudoroff (ED), pentose-phosphate (PP), and lower Embden–Meyerhoff–Parnas (EMP) pathways, which produce reducing power through NAD(P)H synthesis and PHA precursors. Fatty acid substrates are metabolized via β-oxidation and de novo synthesis of fatty acids into PHAs. The analysis of 194 Burkholderia s.l. genomes revealed that all strains have the phaC, phaA, and phaB genes for PHA synthesis, wherein the phaC gene is generally present in ≥2 copies. PHA synthases were classified into four phylogenetic groups belonging to class I II and III PHA synthases and one outlier group. The reconstruction of PHAs synthesis revealed a high level of gene redundancy probably reflecting complex regulatory layers that provide fine tuning according to diverse substrates and physiological conditions.

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