scholarly journals Measuring Alphavirus Fidelity Using Non-Infectious Virus Particles

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 546 ◽  
Author(s):  
Edward I. Patterson ◽  
Kamil Khanipov ◽  
Daniele M. Swetnam ◽  
Samantha Walsdorf ◽  
Tiffany F. Kautz ◽  
...  
Keyword(s):  
Cleavage Site ◽  
Mutation Frequency ◽  
Infectious Virus ◽  
Sequencing Analysis ◽  
Venezuelan Equine Encephalitis ◽  
Virus Particles ◽  
Equine Encephalitis Virus ◽  
Next Generation Sequencing Analysis ◽  
Multiple Replication ◽  
Selection Of

Mutations are incorporated into the genomes of RNA viruses at an optimal frequency and altering this precise frequency has been proposed as a strategy to create live-attenuated vaccines. However, determining the effect of specific mutations that alter fidelity has been difficult because of the rapid selection of the virus population during replication. By deleting residues of the structural polyprotein PE2 cleavage site, E3Δ56-59, in Venezuelan equine encephalitis virus (VEEV) TC-83 vaccine strain, non-infectious virus particles were used to assess the effect of single mutations on mutation frequency without the interference of selection that results from multiple replication cycles. Next-generation sequencing analysis revealed a significantly lower frequency of transversion mutations and overall mutation frequency for the fidelity mutants compared to VEEV TC-83 E3Δ56-59. We demonstrate that deletion of the PE2 cleavage site halts virus infection while making the virus particles available for downstream sequencing. The conservation of the site will allow the evaluation of suspected fidelity mutants across alphaviruses of medical importance.

scholarly journals A Low Fidelity Virus Shows Increased Recombination during the Removal of an Alphavirus Reporter Gene

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 660
Author(s):  
Tiffany F. Kautz ◽  
Elizabeth Jaworski ◽  
Andrew Routh ◽  
Naomi L. Forrester
Keyword(s):  
Reporter Gene ◽  
Virus Population ◽  
Rna Recombination ◽  
Venezuelan Equine Encephalitis ◽  
Live Attenuated Vaccine ◽  
Equine Encephalitis Virus ◽  
Gfp Gene ◽  
Rapid Removal ◽  
Minority Variant ◽  
Multiple Replication

Reporter genes for RNA viruses are well-known to be unstable due to putative RNA recombination events that excise inserted nucleic acids. RNA recombination has been demonstrated to be co-regulated with replication fidelity in alphaviruses, but it is unknown how recombination events at the minority variant level act, which is important for vaccine and trans-gene delivery design. Therefore, we sought to characterize the removal of a reporter gene by a low-fidelity alphavirus mutant over multiple replication cycles. To examine this, GFP was inserted into TC-83, a live-attenuated vaccine for the alphavirus Venezuelan equine encephalitis virus, as well as a low-fidelity variant of TC-83, and passaged until fluorescence was no longer observed. Short-read RNA sequencing using ClickSeq was performed to determine which regions of the viral genome underwent recombination and how this changed over multiple replication cycles. A rapid removal of the GFP gene was observed, where minority variants in the virus population accumulated small deletions that increased in size over the course of passaging. Eventually, these small deletions merged to fully remove the GFP gene. The removal was significantly enhanced during the passaging of low-fidelity TC-83, suggesting that increased levels of recombination are a defining characteristic of this mutant.

scholarly journals Bioinformatics and Computational Tools for Next-Generation Sequencing Analysis in Clinical Genetics

2020 ◽  
Vol 9 (1) ◽  
pp. 132 ◽  
Author(s):  
Rute Pereira ◽  
Jorge Oliveira ◽  
Mário Sousa
Keyword(s):  
Next Generation Sequencing ◽  
Clinical Genetics ◽  
Sequencing Analysis ◽  
Next Generation ◽  
Process Data ◽  
Next Generation Sequencing Analysis ◽  
Generate Process ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Selection Of

Clinical genetics has an important role in the healthcare system to provide a definitive diagnosis for many rare syndromes. It also can have an influence over genetics prevention, disease prognosis and assisting the selection of the best options of care/treatment for patients. Next-generation sequencing (NGS) has transformed clinical genetics making possible to analyze hundreds of genes at an unprecedented speed and at a lower price when comparing to conventional Sanger sequencing. Despite the growing literature concerning NGS in a clinical setting, this review aims to fill the gap that exists among (bio)informaticians, molecular geneticists and clinicians, by presenting a general overview of the NGS technology and workflow. First, we will review the current NGS platforms, focusing on the two main platforms Illumina and Ion Torrent, and discussing the major strong points and weaknesses intrinsic to each platform. Next, the NGS analytical bioinformatic pipelines are dissected, giving some emphasis to the algorithms commonly used to generate process data and to analyze sequence variants. Finally, the main challenges around NGS bioinformatics are placed in perspective for future developments. Even with the huge achievements made in NGS technology and bioinformatics, further improvements in bioinformatic algorithms are still required to deal with complex and genetically heterogeneous disorders.

scholarly journals Characterization of tulip streak virus, a novel virus associated with the family Phenuiviridae

2020 ◽  
Author(s):  
Yutaro Neriya ◽  
Toshiyuki Morikawa ◽  
Kakeru Hamamoto ◽  
Kengo Noguchi ◽  
Tominari Kobayashi ◽  
...  
Keyword(s):  
Chenopodium Quinoa ◽  
Streak Virus ◽  
Sequencing Analysis ◽  
Virus Particles ◽  
The Family ◽  
Next Generation Sequencing Analysis ◽  
Electron Microscopy Analysis ◽  
Complete Sequences ◽  
Microscopy Analysis

In Japan, tulip-growing areas have been plagued by viral diseases for decades, but the viruses causing the damage remain undescribed. In this study, Nicotiana benthamiana and Chenopodium quinoa plants mechanically inoculated with crude sap from a symptomatic tulip flower exhibited necrosis symptoms. Additionally, flexuous and filamentous virus particles were detected by electron microscopy analysis. Moreover, we determined the complete sequences of two genomic segments of the tulip streak virus (TuSV), which is a new virus associated with streaking symptoms, on the basis of a next-generation sequencing analysis. Homology analyses of the amino acid sequence of RNA-dependent RNA polymerase and the terminal sequence of the genomic RNA indicated that TuSV is associated with viruses in the family Phenuiviridae, but differs substantially from other reported viruses.

scholarly journals Resveratrol Inhibits Venezuelan Equine Encephalitis Virus Infection by Interfering with the AKT/GSK Pathway

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 346
Author(s):  
Caitlin W. Lehman ◽  
Kylene Kehn-Hall ◽  
Megha Aggarwal ◽  
Nicole R. Bracci ◽  
Han-Chi Pan ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Fluorescent Protein ◽  
Glycogen Synthase ◽  
Venezuelan Equine Encephalitis Virus ◽  
Encephalitis Virus ◽  
Host Cells ◽  
Dynamics Simulation ◽  
Luciferase Reporter ◽  
Venezuelan Equine Encephalitis ◽  
Equine Encephalitis Virus

The host proteins Protein Kinase B (AKT) and glycogen synthase kinase-3 (GSK-3) are associated with multiple neurodegenerative disorders. They are also important for the replication of Venezuelan equine encephalitis virus (VEEV), thereby making the AKT/GSK-3 pathway an attractive target for developing anti-VEEV therapeutics. Resveratrol, a natural phytochemical, has been shown to substantially inhibit the AKT pathway. Therefore, we attempted to explore whether it exerts any antiviral activity against VEEV. In this study, we utilized green fluorescent protein (GFP)- and luciferase-encoding recombinant VEEV to determine the cytotoxicity and antiviral efficacy via luciferase reporter assays, flow cytometry, and immunofluorescent assays. Our results indicate that resveratrol treatment is capable of inhibiting VEEV replication, resulting in increased viability of Vero and U87MG cells as well as reduced virion production and viral RNA contents within host cells for at least 48 h with a single treatment. Furthermore, the suppression of apoptotic signaling adaptors, caspase-3, caspase-7, and annexin V may also be implicated in resveratrol-mediated antiviral activity. We found that decreased phosphorylation of the AKT/GSK-3 pathway, mediated by resveratrol, can be triggered during the early stages of VEEV infection, suggesting that resveratrol disrupts the viral replication cycle and consequently promotes cell survival. Finally, molecular docking and dynamics simulation studies revealed that resveratrol can directly bind to VEEV glycoproteins, which may interfere with virus attachment and entry. In conclusion, our results suggest that resveratrol exerts inhibitory activity against VEEV infection and upon further modification could be a useful compound to study in neuroprotective research and veterinary sciences.

scholarly journals Next-Generation Sequencing Analysis of the Tineola bisselliella Larval Gut Transcriptome Reveals Candidate Enzymes for Keratin Digestion

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1113
Author(s):  
Michael Schwabe ◽  
Sven Griep ◽  
Henrike Schmidtberg ◽  
Rudy Plarre ◽  
Alexander Goesmann ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Disulfide Bonds ◽  
Differentially Expressed ◽  
Intestinal Microbiome ◽  
Sequencing Analysis ◽  
High Quality ◽  
Transcriptomic Data ◽  
Next Generation Sequencing Analysis ◽  
Generation Sequencing ◽  
Tineola Bisselliella

The clothes moth Tineola bisselliella is one of a few insects that can digest keratin, leading to the destruction of clothing, textiles and artwork. The mechanism of keratin digestion is not yet fully understood, partly reflecting the lack of publicly available genomic and transcriptomic data. Here we present a high-quality gut transcriptome of T. bisselliella generated from larvae reared on keratin-rich and keratin-free diets. The overall transcriptome consists of 428,221 contigs that were functionally annotated and screened for candidate enzymes involved in keratin utilization. As a mechanism for keratin digestion, we identified cysteine synthases, cystathionine β-synthases and cystathionine γ-lyases. These enzymes release hydrogen sulfite, which may reduce the disulfide bonds in keratin. The dataset also included 27 differentially expressed contigs with trypsin domains, among which 20 were associated with keratin feeding. Finally, we identified seven collagenases that were upregulated on the keratin-rich diet. In addition to this enzymatic repertoire potentially involved in breaking down keratin, our analysis of poly(A)-enriched and poly(A)-depleted transcripts suggested that T. bisselliella larvae possess an unstable intestinal microbiome that may nevertheless contribute to keratin digestion.

scholarly journals MicroRNAs from Snellenius manilae bracovirus regulate innate and cellular immune responses of its host Spodoptera litura

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cheng-Kang Tang ◽  
Chih-Hsuan Tsai ◽  
Carol-P. Wu ◽  
Yu-Hsien Lin ◽  
Sung-Chan Wei ◽  
...  
Keyword(s):  
Immune Responses ◽  
Spodoptera Litura ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Sequencing Analysis ◽  
Innate Immune Responses ◽  
Cellular Immune Responses ◽  
Next Generation Sequencing Analysis ◽  
Cellular Immune ◽  
Generation Sequencing

AbstractTo avoid inducing immune and physiological responses in insect hosts, parasitoid wasps have developed several mechanisms to inhibit them during parasitism, including the production of venom, specialized wasp cells, and symbioses with polydnaviruses (PDVs). These mechanisms alter the host physiology to give the wasp offspring a greater chance of survival. However, the molecular mechanisms for most of these alterations remain unclear. In the present study, we applied next-generation sequencing analysis and identified several miRNAs that were encoded in the genome of Snellenius manilae bracovirus (SmBV), and expressed in the host larvae, Spodoptera litura, during parasitism. Among these miRNAs, SmBV-miR-199b-5p and SmBV-miR-2989 were found to target domeless and toll-7 in the host, which are involved in the host innate immune responses. Microinjecting the inhibitors of these two miRNAs into parasitized S. litura larvae not only severely decreased the pupation rate of Snellenius manilae, but also restored the phagocytosis and encapsulation activity of the hemocytes. The results demonstrate that these two SmBV-encoded miRNAs play an important role in suppressing the immune responses of parasitized hosts. Overall, our study uncovers the functions of two SmBV-encoded miRNAs in regulating the host innate immune responses upon wasp parasitism.

scholarly journals Mutation Profile of Aggressive Pheochromocytoma and Paraganglioma with Comparison of TCGA Data

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2389
Author(s):  
Yun Mi Choi ◽  
Jinyeong Lim ◽  
Min Ji Jeon ◽  
Yu-Mi Lee ◽  
Tae-Yon Sung ◽  
...  
Keyword(s):  
Somatic Mutations ◽  
The Cancer Genome Atlas ◽  
Sequencing Analysis ◽  
Poor Overall Survival ◽  
Sdhb Mutation ◽  
Targeted Next Generation Sequencing ◽  
Mutation Profile ◽  
Next Generation Sequencing Analysis ◽  
Number Variation ◽  
Frequent Mutations

In pheochromocytoma and paraganglioma (PPGL), germline or somatic mutations in one of the known susceptibility genes are identified in up to 60% patients. However, the peculiar genetic events that drive the aggressive behavior including metastasis in PPGL are poorly understood. We performed targeted next-generation sequencing analysis to characterize the mutation profile in fifteen aggressive PPGL patients and compared accessible data of aggressive PPGLs from The Cancer Genome Atlas (TCGA) with findings of our cohort. A total of 115 germline and 34 somatic variants were identified with a median 0.58 per megabase tumor mutation burden in our cohort. The most frequent mutation was SDHB germline mutation (27%) and the second frequent mutations were somatic mutations for SETD2, NF1, and HRAS (13%, respectively). Patients were subtyped into three categories based on the kind of mutated genes: pseudohypoxia (n = 5), kinase (n = 5), and unknown (n = 5) group. In copy number variation analysis, deletion of chromosome arm 1p harboring SDHB gene was the most frequently observed. In our cohort, SDHB mutation and pseudohypoxia subtype were significantly associated with poor overall survival. In conclusion, subtyping of mutation profile can be helpful in aggressive PPGL patients with heterogeneous prognosis to make relevant follow-up plan and achieve proper treatment.

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