Recognition of six additional cystoviruses : Pseudomonas virus phi6 is no longer the sole species of the family Cystoviridae

Cystoviridae is a family of bacterial viruses (bacteriophages) with a tri-segmented dsRNA genome. It includes a single genus Cystovirus, which has presently only one recognised virus species, Pseudomonas virus phi6. However, a large number of additional dsRNA phages have been isolated from various environmental samples, indicating that such viruses are more widespread and abundant than previously recognised. Six of the additional dsRNA phage isolates (Pseudomonas phages phi8, phi12, phi13, phi2954, phiNN and phiYY) have been fully sequenced. They all infect Pseudomonas species, primarily plant pathogenic Pseudomonas syringae strains. Due to the notable genetic and structural similarities with Pseudomonas phage phi6, we propose that these viruses should be included into the Cystovirus genus (and consequently into the Cystoviridae family). Here, we present an updated taxonomy of the family Cystoviridae and give a short overview of the properties of the type member phi6 as well as the putative new members of the family.Peer reviewe

ICTV Virus Taxonomy Profile : Cystoviridae

The family Cystoviridae includes enveloped viruses with a tri-segmented dsRNA genome and a double-layered protein capsid. The innermost protein shell is a polymerase complex responsible for genome packaging, replication and transcription. Cystoviruses infect Gram-negative bacteria, primarily plant-pathogenic Pseudomonas syringae strains. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Cystoviridae, which is available at http://www. ictv. global/report/cystoviridae.Non peer reviewe

Kielen rakennustelineillä: kielellisen ja yhteiskunnallisen käänteen merkitys

Kielellinen käänne on ihmis- ja yhteiskuntatieteissä usein käytetty käsite. Harvoin sitä kuitenkaan määritellään tai pohditaan sen enempää. Sosiaalisen konstruktionismin viitekehykseen perustuva kielellinen käänne sekä kuvaa, muokkaa että rakentaa niin teorian kuin käytännönkin tasolla kielen yhteiskunnallistumista ja yhteiskunnan kielellistymistä. Kirjoituksessa kartoitetaan käsitteen historiallista syntyä, sen merkitystä suomalaisessa yhteiskunnallisessa ja humanistisessa tutkimuksessa sekä ongelmia, joita käsitteen soveltamisessa voidaan nähdä, ja mahdollisuuksia, joita se tarjoaa. Näkemyksemme mukaan kieli voidaan ajatella resurssina, joka suhteutuu makrorakenteisin, ja tutkija voi tietyn tilanteen kielenkäyttöä yksityiskohtaisesti tarkastelemalla tutkia niin kielenkäytön mikrotasoa kuin myös ympäröivän yhteiskunnan makrotasoa. Tutkimuksessa tämä yksityiskohtainen analyysi avaa näkökulman, jonka avulla voidaan pohtia, kuvata ja teoretisoida kielten huokoisia eroja ja rajoja, kielenkäyttäjän toimintaa ja valintoja, kielen kantamia valtarakenteita sekä kielenkäytön ja ympäröivän yhteiskunnan suhdetta. Kielen resurssiluonne mahdollistaa sen, että erilaiset humanistiset ja yhteiskuntatieteelliset tutkimusalat voivat todellisesti hyödyttää ja hyödyntää toisiaan

LANGUAGE IDEOLOGIES IN ELDERCARE : CONCEPTIONS OF EFFECTIVE COMMUNICATION AND LANGUAGE USE BY THE RESIDENTS, NURSES AND MANAGERS OF RETIREMENT HOMES

Peer reviewe

Half a Century of Research on Membrane-Containing Bacteriophages: Bringing New Concepts to Modern Virology

Half a century of research on membrane-containing phages has had a major impact on virology, providing new insights into virus diversity, evolution and ecological importance. The recent revolutionary technical advances in imaging, sequencing and lipid analysis have significantly boosted the depth and volume of knowledge on these viruses. This has resulted in new concepts of virus assembly, understanding of virion stability and dynamics, and the description of novel processes for viral genome packaging and membrane-driven genome delivery to the host. The detailed analyses of such processes have given novel insights into DNA transport across the protein-rich lipid bilayer and the transformation of spherical membrane structures into tubular nanotubes, resulting in the description of unexpectedly dynamic functions of the membrane structures. Membrane-containing phages have provided a framework for understanding virus evolution. The original observation on membrane-containing bacteriophage PRD1 and human pathogenic adenovirus has been fundamental in delineating the concept of “viral lineages”, postulating that the fold of the major capsid protein can be used as an evolutionary fingerprint to trace long-distance evolutionary relationships that are unrecognizable from the primary sequences. This has brought the early evolutionary paths of certain eukaryotic, bacterial, and archaeal viruses together, and potentially enables the reorganization of the nearly immeasurable virus population (~1 × 1031) on Earth into a reasonably low number of groups representing different architectural principles. In addition, the research on membrane-containing phages can support the development of novel tools and strategies for human therapy and crop protection

Black box of phage-bacterium interactions : exploring alternative phage infection strategies

The canonical lytic-lysogenic binary has been challenged in recent years, as more evidence has emerged on alternative bacteriophage infection strategies. These infection modes are little studied, and yet they appear to be more abundant and ubiquitous in nature than previously recognized, and can play a significant role in the ecology and evolution of their bacterial hosts. In this review, we discuss the extent, causes and consequences of alternative phage lifestyles, and clarify conceptual and terminological confusion to facilitate research progress. We propose distinct definitions for the terms 'pseudolysogeny' and 'productive or non-productive chronic infection', and distinguish them from the carrier state life cycle, which describes a population-level phenomenon. Our review also finds that phages may change their infection modes in response to environmental conditions or the physiological state of the host cell. We outline known molecular mechanisms underlying the alternative phage-host interactions, including specific genetic pathways and their considerable biotechnological potential. Moreover, we discuss potential implications of the alternative phage lifestyles for microbial biology and ecosystem functioning, as well as applied topics such as phage therapy.Peer reviewe

ICTV Virus Taxonomy Profile: Finnlakeviridae

Finnlakeviridae is a family of icosahedral, internal membrane-containing bacterial viruses with circular, single-stranded DNA genomes. The family includes the genus, Finnlakevirus, with the species, Flavobacterium virus FLiP. Flavobacterium phage FLiP was isolated with its Gram-negative host bacterium from a boreal freshwater habitat in Central Finland in 2010. It is the first described single-stranded DNA virus with an internal membrane and shares minimal sequence similarity with other known viruses. The virion organization (pseudo T=21 dextro) and major capsid protein fold (double-beta-barrel) resemble those of Pseudoalteromonas phage PM2 (family Corticoviridae), which has a double-stranded DNA genome. A similar major capsid protein fold is also found in other double-stranded DNA viruses in the kingdom Bamfordvirae.Non peer reviewe