Download or read book Archaeal Virus host Interactions written by Tessa Quax and published by . This book was released on 2013 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis provides novel insights in several aspects of the molecular biology of Archaea, Bacteria and their viruses. The archaeal virus Sulfolobus islandicus rod-shaped virus 2 (SIRV2), has a remarkable infection cycle. Infection with SIRV2 results in the formation of large virus associated pyramids (VAPs) on the host cell surface. The pyramids open during the final step of the infection cycle, to allow the release of virions. This virus release mechanism is unique. The VAPs are formed by self-assembly of one virus-encoded protein, PVAP. VAPs exist as discrete particles, and are baseless pyramids with heptagonal perimeter. The assembly process of the VAPs is described, based on cryo-electron tomography experiments and mutational analysis of PVAP. VAPs consists of two layers of which the outer one continuous with the cell membrane. PVAP expression in bacterial and eukaryotic cells resulted in VAP formation on nearly all membranes, demonstrating that PVAP serves as a universal membrane remodeling system, which might be exploited for biotechnological purposes. Whole transcriptome sequencing allowed determination of a global map of virus and host gene expression during the infection cycle. Host genes involved in anti-viral defence are activated (i.e. CRISPR-Cas and toxin anti-toxin systems). The multi-subunit protein complexes crucial for CRISPR anti-viral defence have an uneven stoichiometry and are encoded on operons. It is shown that differential translation is a key determinant of modulated expression of genes clustered in operons and that codon bias generally is the best in silico indicator of unequal protein production.
Download or read book Encyclopedia of Virology written by and published by Academic Press. This book was released on 2021-02-24 with total page 4109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Virology, Fourth Edition, Five Volume Set builds on the solid foundation laid by the previous editions, expanding its reach with new and timely topics. In five volumes, the work provides comprehensive coverage of the whole virosphere, making this a unique resource. Content explores viruses present in the environment and the pathogenic viruses of humans, animals, plants and microorganisms. Key areas and concepts concerning virus classification, structure, epidemiology, pathogenesis, diagnosis, treatment and prevention are discussed, guiding the reader through chapters that are presented at an accessible level, and include further readings for those needing more specific information. More than ever now, with the Covid19 pandemic, we are seeing the huge impact viruses have on our life and society. This encyclopedia is a must-have resource for scientists and practitioners, and a great source of information for the wider public. Offers students and researchers a one-stop shop for information on virology not easily available elsewhere Fills a critical gap of information in a field that has seen significant progress in recent years Authored and edited by recognized experts in the field, with a range of different expertise, thus ensuring a high-quality standard
Download or read book Archaeal Host Virus Interactions written by Jennifer Fulton Wirth and published by . This book was released on 2011 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viruses are the most abundant biological entity on earth, and virus-host interactions are one of the most important factors shaping microbial populations (Suttle, 2007b). The study of both the cellular and viral members of the domain Archaea is a relatively new field. Thus, the viruses (and their cellular hosts) of Archaea are poorly understood as compared to viruses of Bacteria and Eukarya. This work has sought to expand our understanding of archaeal viruses by two general approaches. The first is by developing and implementing the use of a genetic system for a crenarchaeal virus, Sulfolobus turreted icosahedral virus (STIV), isolated from a hot (82°C) acidic (pH 2.2) pool in Yellowstone National Park, USA. The second approach has been to look at viral communities and their interactions with their cellular hosts in natural environments. We have developed a genetic tool, an infectious clone for STIV, which has allowed for genetic analysis of this virus. A number of viral genes have been knocked out, and their functions investigated using this tool. We have determined that at least three viral genes, A197, B345 and C381, are required for viral replication, while one gene, B116, is not essential. Work continues investigating function for other STIV genes as well as specific interactions with its host, Sulfolobus solfataricus. We have performed total community sequencing (metagenomics) for both the cellular and viral populations of several hot springs in Yellowstone National Park. We have been able to assemble a near full-length putative novel viral genome from one of these sites. We have also performed an in depth analysis of the function of a newly described bacterial and archaeal adaptive immune system (CRISPR/Cas) in a natural environment. This study has provided insights into the function of this immune system in a complex nutrient limited environment, which would not have been observed by studying cultured isolates in a laboratory.
Download or read book Isolation and Characterization of Hyperthermophilic Archaeal Viruses written by Diana Paola Baquero Uriza and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme geothermal environments are inhabited by archaeal viruses with unique genome contents and remarkable morphologies, many of which have not been described among viruses infecting bacteria or eukaryotes. However, the number of known species of viruses infecting archaea remains low compared to the eukaryotic or bacterial viruses. Moreover, the lack of relationships to other known viruses and distinctiveness of their genomes suggest that the mechanisms of virus-host interaction are likely to be also novel. Therefore, in the framework of my studies, I have focused on two major lines of research: (i) isolation and characterization of new hyperthermophilic archaeal viruses and (ii) molecular mechanisms of virus-host interactions in Archaea. We investigated the virus diversity in the sulfurous fields of the Campi Flegrei volcano in Pozzuoli, Italy. Five new archaeal viruses infecting neutrophilic hyperthermophiles of the genus Pyrobaculum and acidophilic hyperthermophiles belonging to three different genera of the order Sulfolobales, namely, Saccharolobus, Acidianus, and Metallosphaera were isolated. The newly characterized viruses belong to the families Rudiviridae, Globuloviridae and Tristromaviridae. Notably, phylogenomic analysis of the newly isolated and previously sequenced rudiviruses revealed a clear biogeographic pattern, with all Italian rudiviruses forming a monophyletic clade, suggesting geographical structuring of virus communities in extreme geothermal environments. One of the non-enveloped rudiviruses isolated in Pozzuoli, namely, Saccharolobus solfataricus rod-shaped virus 1 (SSRV1), and the enveloped Sulfolobus islandicus filamentous virus (SIFV) were structurally and biochemically characterized. The study has revealed conserved structural features shared by these viruses and clarified the evolutionary relationship between non-enveloped and enveloped filamentous viruses. The second line of research focused on understanding the mechanisms of virion assembly and release on the example of the enveloped filamentous virus SIFV, which infects the hyperthermophilic and acidophilic archaeon Sulfolobus islandicus. Our results showed that SIFV is a lytic virus, which is released through pyramidal portals formed in the host cell membrane, a highly unexpected egress mechanism for an enveloped virus. Interestingly, dual-axis electron tomography revealed that SIFV virions acquire their lipid envelopes inside the host through an unknown mechanism, involving either de novo membrane formation or trafficking of lipids from the cytoplasmic membrane to virion assembly centers.
Download or read book Virus Structure written by and published by Elsevier. This book was released on 2003-10-02 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virus Structure covers the full spectrum of modern structural virology. Its goal is to describe the means for defining moderate to high resolution structures and the basic principles that have emerged from these studies. Among the topics covered are Hybrid Vigor, Structural Folds of Viral Proteins, Virus Particle Dynamics, Viral Gemone Organization, Enveloped Viruses and Large Viruses. Covers viral assembly using heterologous expression systems and cell extracts Discusses molecular mechanisms in bacteriophage T7 procapsid assembly, maturation and DNA containment Includes information on structural studies on antibody/virus complexes
Download or read book Biocommunication of Phages written by Guenther Witzany and published by Springer Nature. This book was released on 2020-06-29 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to systemize all levels of communicative behavior of phages. Phages represent the most diverse inhabitants on this planet. Until today they are completely underestimated in their number, skills and competences and still remain the dark matter of biology. Phages have serious effects on global energy and nutrient cycles. Phages actively compete for host. They can distinguish between ‘self’ and ‘non-self’ (complement same, preclude others). They process and evaluate available information and then modify their behaviour accordingly. These diverse competences show us that this capacity to evaluate information is possible owing to communication processes within phages (intra-organismic), between the same, related and different phage species (interorganismic), and between phages and non-phage organisms (transorganismic). This is crucial in coordinating infection strategies (lytic vs. lysogenic) and recombination in phage genomes. In 22 chapters, expert contributors review current research into the varying forms of phage biocommunication and Phagetherapy. Biocommunication of Phages aims to assess the current state of research, to orient further investigations on how phages communicate with each other to coordinate their behavioral patterns, and to inspire further investigation of the role of non-phage viruses (non-lytic, non-prokaryotic) in these highly dynamic interactional networks.
Download or read book Viruses Essential Agents of Life written by Günther Witzany and published by Springer Science & Business Media. This book was released on 2012-11-13 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: A renaissance of virus research is taking centre stage in biology. Empirical data from the last decade indicate the important roles of viruses, both in the evolution of all life and as symbionts of host organisms. There is increasing evidence that all cellular life is colonized by exogenous and/or endogenous viruses in a non-lytic but persistent lifestyle. Viruses and viral parts form the most numerous genetic matter on this planet.
Download or read book Sequence based Bioinformatics Approaches to Predict Virus host Relationships in Archaea and Eukaryotes written by Yingshan Li and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viral metagenomics is independent of lab culturing and capable of investigating viromes of virtually any given environmental niches. While numerous sequences of viral genomes have been assembled from metagenomic studies over the past years, the natural hosts for the majority of these viral contigs have not been determined. Different computational approaches have been developed to predict hosts of bacteria phages. Nevertheless, little progress has been made in the virus-host prediction, especially for viruses that infect eukaryotes and archaea. In this study, by analyzing all documented viruses with known eukaryotic and archaeal hosts, we assessed the predictive power of four computational approaches in viral host prediction. The use of the following biological relationships among viruses and hosts were explored: 1. Sequence similarity between virus and host genome, where direct genetic interactions between viruses and hosts are assumed to leave traces of historical infections. 2. Co-evolution between viruses and hosts, where the viral dependency on their hosts for replication is assumed to result in similar genomic features including nucleotide composition and codon usage. 3. Sequence similarity between viruses, where closely related viruses are assumed to infect the same hosts. And 4. genomic feature similarities between viruses based on nucleotide compositions and dinucleotide/codon/bicodon usage biases. We assume that viruses with similar genomic features tend to share the same hosts. We showed that using any of the four approaches produced better predictions than uninformed guesses, indicating that our current knowledge of virus-host interaction and co-evolution can be exploited to help predict natural hosts among eukaryotes and archaea for viral contigs. Overall, the third and fourth approaches (prediction based on virus-virus genomic sequence similarity and genomic feature similarity) had the highest prediction accuracy. The second approach (prediction based on virus-host co-evolution) has the least predictive power. We also discuss the biological underpinnings of different predictive power shown in each of these approaches. We anticipate a significant increase in predictive capacity as more training data and knowledge of virus-host relationships are accumulated in the future.
Download or read book Comprehensive Virology written by Heinz Fraenkel-Conrat and published by Springer. This book was released on 1980-11-01 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having passed only recently through its descriptive phase of naming and num bering, has probably reached that stage at which relatively few new truly new-viruses will be discovered. Triggered by the intellectual probes and techniques of molecular biology, genetics, biochemical cytology, and high resolution microscopy and spectroscopy, the field has experienced a genuine information explosion. Few serious attempts have been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of about 18 volumes, represents a commitment by a large group of active investigators to analyze, digest, and expostulate on the great mass of data relating to viruses, much of which is now amorphous and disjointed, and scattered throughout a wide literature. In this way, we hope to place the entire field in perspective, and to develop an invalua ble reference and sourcebook for researchers and students at all levels. This series is designed as a continuum that can be entered anywhere, but which also provides a logical progression of developing facts and integrated concepts.
Download or read book Life in Extreme Environments written by Ricardo Amils Pibernat and published by Springer Science & Business Media. This book was released on 2007-07-21 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an intriguing look at how life can adapt to many different extreme environments. It addresses the limits for life development and examines different strategies used by organisms to adapt to different extreme environments.
Download or read book Principles of Molecular Virology written by Alan Cann and published by Elsevier. This book was released on 2005-07-26 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Principles of Molecular Virology, Fourth Edition" provides an essential introduction to modern virology in a clear and concise manner. It is a highly enjoyable and readable text with numerous illustrations that enhance the reader's understanding of important principles. It contains new material on virus structure, virus evolution, zoonoses, bushmeat, SARS and bioterrorism. The standard version includes a CD-ROM with Flash animations, virtual interactive tutorials and experiments, self-assessment questions, useful online resources, along with the glossary, classification of subcellular infectious agents and history of virology.
Download or read book Virus Bioinformatics written by Manja Marz and published by MDPI. This book was released on 2020-02-21 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virus bioinformatics is evolving and succeeding as an area of research in its own right, representing the interface of virology and computer science. Bioinformatic approaches to investigate viral infections and outbreaks have become central to virology research, and have been successfully used to detect, control, and treat infections of humans and animals. As part of the Third Annual Meeting of the European Virus Bioinformatics Center (EVBC), we have published this Special Issue on Virus Bioinformatics.
Download or read book Bacteriophages written by David R. Harper and published by Springer Nature. This book was released on 2021-01-30 with total page 1376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first major reference work dedicated to the mannifold industrial and medical applications of bacteriophages provides both theoretical and practical insights into the emerging field of bacteriophage biotechnology. The book introduces to bacteriophage biology, ecology and history and reviews the latest technologies and tools in bacteriophage detection, strain optimization and nanotechnology. Usage of bacteriophages in food safety, agriculture, and different therapeutic areas is discussed in detail. This book serves as essential guide for researchers in applied microbiology, biotechnology and medicine coming from both academia and industry.
Download or read book DNA Traffic in the Environment written by Hiromi Nishida and published by Springer. This book was released on 2019-02-21 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprehensively discusses our current understanding of the role and biological mechanisms of horizontal transfer of genetic elements in the environment, which has been important in the evolution of prokaryotes (archaea and bacteria). Horizontal transfer of genetic elements generates variations of prokaryotes and their genomes. Comparative studies of genomes revealed that it frequently occurred during archaeal and bacterial evolution. The book introduces a variety of studies related to horizontal gene transfer, gene silencing, plasmids, phages, transposons, and the emergence of microbes that degrade man-made xenobiotics and have antimicrobial resistance. Written by leading researchers in DNA traffic, the book is a valuable guide to horizontal transfer for both young scientists and experts in the field.
Download or read book Origin and Evolution of Viruses written by Esteban Domingo and published by Elsevier. This book was released on 2008-06-23 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: New viral diseases are emerging continuously. Viruses adapt to new environments at astounding rates. Genetic variability of viruses jeopardizes vaccine efficacy. For many viruses mutants resistant to antiviral agents or host immune responses arise readily, for example, with HIV and influenza. These variations are all of utmost importance for human and animal health as they have prevented us from controlling these epidemic pathogens. This book focuses on the mechanisms that viruses use to evolve, survive and cause disease in their hosts. Covering human, animal, plant and bacterial viruses, it provides both the basic foundations for the evolutionary dynamics of viruses and specific examples of emerging diseases. NEW - methods to establish relationships among viruses and the mechanisms that affect virus evolution UNIQUE - combines theoretical concepts in evolution with detailed analyses of the evolution of important virus groups SPECIFIC - Bacterial, plant, animal and human viruses are compared regarding their interation with their hosts
Download or read book Archaea written by Roger A. Garrett and published by John Wiley & Sons. This book was released on 2008-05-12 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduced by Crafoord Prize winner Carl Woese, this volumecombines reviews of the major developments in archaeal researchover the past 10–15 years with more specialized articlesdealing with important recent breakthroughs. Drawing on majorthemes presented at the June 2005 meeting held in Munich to honorthe archaea pioneers Wolfram Zillig and Karl O. Stetter, the bookprovides a thorough survey of the field from its controversialbeginnings to its ongoing expansion to include aspects ofeukaryotic biology. The editors have assembled articles from the premier researchersin this rapidly burgeoning field, including an account by CarlWoese of his original discovery of the Archaea (until 1990 termedarchaebacteria) and the initially mixed reactions of the scientificcommunity. The review chapters and specialized articles address theemerging significance of the Archaea within a broader scientificand technological context, and include accounts of cutting-edgeresearch developments. The book spans archaeal evolution,physiology, and molecular and cellular biology and will be anessential reference for both graduate students and researchers.
Download or read book Studies of Archaeal Virus host Systems in Thermal Environments written by and published by . This book was released on 2013 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
