Association of Paramecium bursaria Chlorella viruses with Paramecium bursaria cells: Ultrastructural studies

Yashchenko, Varvara; Gavrilova, O. V.; Rautian, Maria; Jakobsen, Kjetill S.

doi:10.1016/j.ejop.2011.05.002

Cited by 20 publications

(16 citation statements)

References 23 publications

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“…Although the presently worked examples are all synthetic (rather than based on real experimental data), the methods that they illustrate have been applied in a wide variety of studies involving bacteria, viruses and animal and plant cells and tissues (for a list of references, see Mayhew 2011). Moreover, they have been adopted in areas other than ICC in order to analyse, for instance, spatial distributions of nanoparticles within cells/ tissues (Mühlfeld et al 2007(Mühlfeld et al , 2008Geiser et al 2013) and the association of viruses with the symbiotic pair of Paramecium and Chlorella (Yashchenko et al 2012). In principle, they could also be applied in immuno-quantum dot cytochemistry (e.g., Nisman et al 2012;Killingsworth et al 2012).…”

Section: Discussionmentioning

confidence: 98%

Quantitative immunocytochemistry at the ultrastructural level: a stereology-based approach to molecular nanomorphomics

Mayhew

2014

Cell Tissue Res

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Biological systems span multiple levels of structural organisation from the macroscopic, via the microscopic, to the nanoscale. Therefore, comprehensive investigation of systems biology requires application of imaging modalities that reveal structure at multiple resolution scales. Nanomorphomics is the part of morphomics devoted to the systematic study of functional morphology at the nanoscale and an important element of its achievement is the combination of immunolabelling and transmission electron microscopy (TEM). The ultimate goal of quantitative immunocytochemistry is to estimate numbers of target molecules (usually peptides, proteins or protein complexes) in biological systems and to map their spatial distributions within them. Immunogold cytochemistry utilises target-specific affinity markers (primary antibodies) and visualisation aids (e.g., colloidal gold particles or silver-enhanced nanogold particles) to detect and localise target molecules at high resolution in intact cells and tissues. In the case of post-embedding labelling of ultrathin sections for TEM, targets are localised as a countable digital readout by using colloidal gold particles. The readout comprises a spatial distribution of gold particles across the section and within the context of biological ultrastructure. The observed distribution across structural compartments (whether volume- or surface-occupying) represents both specific and non-specific labelling; an assessment by eye alone as to whether the distribution is random or non-random is not always possible. This review presents a coherent set of quantitative methods for testing whether target molecules exhibit preferential and specific labelling of compartments and for mapping the same targets in two or more groups of cells as their TEM immunogold-labelling patterns alter after experimental manipulation. The set also includes methods for quantifying colocalisation in multiple-labelling experiments and mapping absolute numbers of colloidal gold particles across compartments at specific positions within cells having a point-like inclusion (e.g., centrosome, nucleolus) and a definable vertical axis. Although developed for quantifying colloidal gold particles, the same methods can in principle be used to quantify other electron-dense punctate nanoparticles, including quantum dots.

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Section: Discussionmentioning

confidence: 98%

Quantitative immunocytochemistry at the ultrastructural level: a stereology-based approach to molecular nanomorphomics

Mayhew

2014

Cell Tissue Res

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“…For example, these endosymbiotic algae may get a certain advantage living in a host with slow growth rate, as propagation enhanced by artificially favorable conditions could be too fast. Other possible explanations of unsuccessful cultivation attempts of symbiotic Meyerella may include low frequency of cyst-like cells formation readily in Paramecium , occasional overgrowth of it by Chlorella if the latter are present in medium or engulfed but not digested by the ciliate, and even presence of a latent virus which activates and lyses the host cells when they start rapid growing outside of Paramecium [84, 85]. …”

Section: Discussionmentioning

confidence: 99%

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium “Candidatus Holospora parva”

et al. 2016

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Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of “green” ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name “Candidatus Holospora parva” for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.

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“…Large plaques were those with a diameter greater than 4 mm, medium plaques, between 1-4 mm; and small plaques, smaller than 1 mm. tend to accumulate and attach to Paramecium bursaria cells (referred to as green paramecium) without actually infecting them [41]. Additionally, Hydra species also maintain a diverse community of eukaryotic viruses, including chloroviruses, as part of their holobiont [42].…”

Section: Algal Hosts Of Chloroviruses In Native Freshwatermentioning

confidence: 99%

Three-year survey of abundance, prevalence and genetic diversity of chlorovirus populations in a small urban lake

et al. 2016

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Inland water environments cover about 2.5 percent of our planet and harbor huge numbers of known and still unknown microorganisms. In this report, we examined water samples for the abundance, prevalence, and genetic diversity of a group of infectious viruses (chloroviruses) that infect symbiotic chlorella-like green algae. Samples were collected on a weekly basis for a period of 24 to 36 months from a recreational freshwater lake in Lincoln, Nebraska, and assayed for infectious viruses by plaque assay. The numbers of infectious virus particles were both host- and site-dependent. The consistent fluctuations in numbers of viruses suggest their impact as key factors in shaping microbial community structures in the water surface. Even in low-viral-abundance months, infectious chlorovirus populations were maintained, suggesting either that the viruses are very stable or that there is ongoing viral production in natural hosts.

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Association of Paramecium bursaria Chlorella viruses with Paramecium bursaria cells: Ultrastructural studies

Cited by 20 publications

References 23 publications

Quantitative immunocytochemistry at the ultrastructural level: a stereology-based approach to molecular nanomorphomics

Quantitative immunocytochemistry at the ultrastructural level: a stereology-based approach to molecular nanomorphomics

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium “Candidatus Holospora parva”

Three-year survey of abundance, prevalence and genetic diversity of chlorovirus populations in a small urban lake

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