Zernike phase contrast electron microscopy of ice-embedded influenza A virus

Yamaguchi, Masashi; Danev, Radostin; Nishiyama, Kiyoto; Sugawara, Keishin; Nagayama, Kuniaki

doi:10.1016/j.jsb.2008.01.009

Cited by 92 publications

(85 citation statements)

References 15 publications

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“…5. Application of more specialized EM imaging techniques to influenza viruses has provided data that are, at least in part, consistent with this arrangement; although not all particles were seen to contain organized bundles of RNPs, no evidence for routine incorporation of more than eight RNPs has been presented (Harris et al, 2006;Yamaguchi et al, 2008).…”

Section: Genome Segmentation: a Mixed Blessingmentioning

confidence: 82%

“…Indeed, it has even been proposed that the viral glycoproteins alone can drive particle assembly and that not all influenza virions even contain a matrix protein layer (Chen et al, 2007;Harris et al, 2006). Instead, as EM analyses suggest that budding influenza A virions incorporate a parallel 7+1 array of eight RNPs (Harris et al, 2006;Noda et al, 2006;Oxford & Hockley, 1987;Yamaguchi et al, 2008), it has been plausibly hypothesized that this represents a specific multi-segmental 'genome complex' containing one copy of each of the eight vRNAs whose assembly confers specificity on packaging (Heggeness et al, 1982;Noda et al, 2006).…”

Section: Mechanisms Of Segment Selectionmentioning

confidence: 99%

“…Although EM imaging indicates that some virions contain a 7+1 array of RNPs, this is not proof of a complex with a specific composition or even that the RNPs are actually associated; the apparent order could potentially result from the geometry of packing eight rods into a spherical particle and/or the mechanism of the budding process itself. Images showing the 7+1 array appear to be less common when released particles are examined, in comparison to sections across budding virions (Booy et al, 1985;Harris et al, 2006;Noda et al, 2006;Oxford & Hockley, 1987;Yamaguchi et al, 2008;Yazaki et al, 1984). This may well be because released particles are free to rotate, reducing the chance of seeing RNPs in cross section, whereas cell-associated virions maintain the directionality of budding.…”

Section: Mechanisms Of Segment Selectionmentioning

confidence: 99%

See 2 more Smart Citations

Genome packaging in influenza A virus

Hutchinson

Kirchbach

Gog

et al. 2009

Journal of General Virology

258

279

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Section: Genome Segmentation: a Mixed Blessingmentioning

confidence: 82%

Section: Mechanisms Of Segment Selectionmentioning

confidence: 99%

Section: Mechanisms Of Segment Selectionmentioning

confidence: 99%

See 1 more Smart Citation

Genome packaging in influenza A virus

Hutchinson

Kirchbach

Gog

et al. 2009

Journal of General Virology

258

279

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“…In addition, ultrastructural changes that are essential to membrane fusion and virion disassembly during cell entry remain to be described. Electron cryomicroscopy of influenza virions that are vitrified by rapid plungefreezing (14)(15)(16)(17) shows contrast from virion structures themselves and not from stain distributions, which can also distort or disrupt virus structure. However, an understanding of the structural organization of influenza virus has remained difficult because of its pleomorphic nature.…”

mentioning

confidence: 99%

Structural organization of a filamentous influenza A virus

Calder

Wasilewski²,

Berriman³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

219

280

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Influenza is a lipid-enveloped, pleomorphic virus. We combine electron cryotomography and analysis of images of frozen-hydrated virions to determine the structural organization of filamentous influenza A virus. Influenza A/Udorn/72 virions are capsule-shaped or filamentous particles of highly uniform diameter. We show that the matrix layer adjacent to the membrane is an ordered helix of the M1 protein and its close interaction with the surrounding envelope determines virion morphology. The ribonucleoprotein particles (RNPs) that package the genome segments form a tapered assembly at one end of the virus interior. The neuraminidase, which is present in smaller numbers than the hemagglutinin, clusters in patches and are typically present at the end of the virion opposite to RNP attachment. Incubation of virus at low pH causes a loss of filamentous morphology, during which we observe a structural transition of the matrix layer from its helical, membrane-associated form to a multilayered coil structure inside the virus particle. The polar organization of the virus provides a model for assembly of the virion during budding at the host membrane. Images and tomograms of A/Aichi/68 X-31 virions show the generality of these conclusions to non-filamentous virions.electron cryomicroscopy | matrix protein | ribonucleoprotein particles hemagglutinin | neuramindase

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“…1-2a. 5) They appeared as spherical or elongated particles consisting of many glycoprotein spikes, a viral envelope, and an inner core. The images were clear and natural with high contrast.…”

Section: Ice-embedding Image Of Influenza Virusmentioning

confidence: 99%

An electron microscopic study of microorganisms: from influenza virus to deep-sea microorganisms

Yamaguchi

2015

Proc. Jpn. Assoc. Mycotoxicol.

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Three topics from electron microscopic studies of microorganisms carried out in my laboratory in recent ten years are described. 1) Influenza A virus was observed in water by an ice-embedding method using phase contrast electron microscopy developed in Japan. Virions appeared as spherical or elongated particles consisting of spikes, an envelope, and a core with high contrast. 2) A new term the "structome" was introduced and defined as "the quantitative and three-dimensional structural information of a whole cell at electron microscopic level." We performed structome analyses of Saccharomyces cerevisiae by using freeze-substitution and serial ultrathin sectioning electron microscopy. We found that there were one to four mitochondria and about 195,000 ribosomes in a cell. 3) In the deep-sea off the coast of Japan, we discovered a unique microorganism appearing to have cellular features intermediate between prokaryotes and eukaryotes. The organism, named as the Myojin parakaryote, was two orders of magnitude larger than a typical bacterium and had a large "nucleoid", surrounded by a single layered "nucleoid membrane", and bacteria-like "endosymbionts", but it lacked mitochondria. This organism exemplifies a potential evolutionary path between prokaryotes and eukaryotes, and the presence of the organism supports the endosymbiotic theory for the origin of mitochondria and the karyogenetic hypothesis for the origin of the nucleus. These studies show that the electron microscopy is a powerful tool for studying a wide range of problems of microorganisms.

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Zernike phase contrast electron microscopy of ice-embedded influenza A virus

Cited by 92 publications

References 15 publications

Genome packaging in influenza A virus

Genome packaging in influenza A virus

Structural organization of a filamentous influenza A virus

An electron microscopic study of microorganisms: from influenza virus to deep-sea microorganisms

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