Der Organismus der Infusionsthiere

Stein, Friedrich

doi:10.5962/bhl.title.3933

Cited by 125 publications

(284 citation statements)

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“…Two ovoid distal parts of the macronucleus are linked by a thin connection. The existence of a macronuclear replication band was probably first observed in lightmicroscopy studies by Friedrich Stein in 1859 (Stein, 1859) and represents another characteristic feature of spirotrichs. Replication in the macronucleus of Stylonychia starts simultaneously at the two distal ends.…”

Section: Introductionmentioning

confidence: 99%

Exploiting nuclear duality of ciliates to analyse topological requirements for DNA replication and transcription

Postberg

Alexandrova

Cremer

et al. 2005

Journal of Cell Science

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Spatial and temporal replication patterns are used to describe higher-order chromatin organisation from nuclei of early metazoan to mammalian cells. Here we demonstrate evolutionary conserved similarities and differences in replication patterns of micronuclei and macronuclei in the spirotrichous ciliate Stylonychia lemnae. Since this organism possesses two kinds of morphologically and functionally different nuclei in one cell, it provides an excellent model system to analyse topological requirements for DNA replication and transcription. Replication in the heterochromatic micronucleus occurs in foci-like structures showing spatial and temporal patterns similar to nuclei of higher eukaryotes, demonstrating that these patterns are inherent features of nuclear architecture. The `nanochromosomes' of the macronucleus are replicated in the propagating replication band. We show that it consists of hundreds of replication foci. Post-replicative macronuclear chromatin remains organised in foci. These foci are not randomly distributed throughout the macronucleus, indicating a higher-order organisation of macronuclear chromatin above the level of `nanochromosomes'. Both telomerase and proliferating cell nuclear antigen (PCNA) occur as foci-like structures in the rear zone of the replication band, suggesting that a wave of chromatin modification driven by a short or continuous exogenous signal permits the assembly of replication factories at predicted sites. We further show that transcription occurs at discrete sites colocalised with putative nucleoli and dispersed chromatin. Common principles of functional nuclear architecture were conserved during eukaryotic evolution. Moreover nuclear duality inherent to ciliates with their germline micronucleus and their somatic macronucleus may eventually provide further insight into epigenetic regulation of transcription, replication and nuclear differentiation.

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Section: Introductionmentioning

confidence: 99%

Exploiting nuclear duality of ciliates to analyse topological requirements for DNA replication and transcription

Postberg

Alexandrova

Cremer

et al. 2005

Journal of Cell Science

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“…However, the identity of the species is doubtful because of two major historical pitfalls referring to both its taxonomy and its nomenclature. Confusion arose since Stein (1883) introduced monotypic Goniodoma F. Stein (1883: 9, 12, 13, 16, 19, 21), which is nomenclaturally based on the name of C.G. Ehrenberg's species.…”

Section: Introductionmentioning

confidence: 99%

Taxonomic clarification of the dinophyte Peridinium acuminatum Ehrenb., ≡ Scrippsiella acuminata, comb. nov. (Thoracosphaeraceae, Peridiniales)

et al. 2015

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Peridinium acuminatum (Peridiniales, Dinophyceae) was described in the first half of the 19th century, but the name has been rarely adopted since then. It was used as type of Goniodoma, Heteraulacus and Yesevius, providing various sources of nomenclatural and taxonomic confusion. Particularly, several early authors emphasised that the organisms investigated by C.G. Ehrenberg and S.F.N.R. von Stein were not conspecific, but did not perform the necessary taxonomic conclusions. The holotype of P. acuminatum is an illustration dating back to 1834, which makes the determination of the species ambiguous. We collected, isolated, and cultivated Scrippsiella acuminata, comb. nov. (strain GeoB 427) from the type locality off Kiel, Germany (Baltic Sea). We barcoded the species of the Thoracosphaeraceae using rRNA sequences and investigated the morphology of the strain using light and electron microscopy. As taxonomic result, we designate an epitype for Peridinium acuminatum, as no conflict with C.G. Ehrenberg’s protologue can be stated. It is indistinguishable from Scrippsiella trochoidea (likewise described from the Kiel Fjord) that we consider a later heterotypic synonym. Our study contributes to the disentanglement of dinophyte taxonomy in a very challenging case, and we trust that C.G. Ehrenberg and S.F.N.R. von Stein investigated different species under the epithet ‘acuminatum’. The complex nomenclature and taxonomy of Goniodoma, and its type species Goniodoma acuminatum, is discussed in the Electronic Supplement. We consider Pyrrhotriadinium, with the type species Pyrrhotriadinium polyedricum (Gonyaulacales), well suited to harbour all gonyaulacalean taxa so far assigned to Goniodoma and Heteraulacus as well.

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“…et Skogsb. In the original illustration of H. crateriformis by Stein (1883), the ACL is as long as about 0.60 of the cell-body length, which is the main distinguishing feature between Stein's specimens and our cells. On the other hand, in their original drawing Kofoid et Skogsberg (1928: pl.…”

Section: Genus Pseudophalacroma Jörgmentioning

confidence: 99%

Dinophysiales (Dinophyceae) del Parque Nacional Sistema Arrecifal Veracruzano, Golfo de México, con clave para identificación

Okolodkov

2014

Acta Bot. Mex.

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The morphology of 38 species from eight genera of the order Dinophysiales was studied based on about seven hundred 20 μm phytoplankton net samples taken from May 2005 through April 2008 at 27 sampling stations in the National Park Sistema Arrecifal Veracruzano, southwestern Gulf of Mexico. Short descriptions and synonyms are given for each species. Cell size variation with the mean and the standard deviation are given for most species. Twentythree species are provided with affinities and morphological, taxonomic and nomenclatural comments. Dichotomous keys for identification of the genera and species of Amphisolenia (4 species), Dinophysis (7), Heteroschisma (1), Histioneis (6), Ornithocercus (7), Phalacroma (9), Pseudophalacroma (1) and Sinophysis (3) are presented, and species are illustrated with light and scanning electron microscope photographs and line drawings. Phalacroma equalanti (Balech) Okolodkov comb. nov. is established. Thirteen species are new records for the State of Veracruz, and Histioneis isseli and Pseudophalacroma nasutum are new for the Gulf of Mexico.

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Der Organismus der Infusionsthiere

Cited by 125 publications

References 0 publications

Exploiting nuclear duality of ciliates to analyse topological requirements for DNA replication and transcription

Exploiting nuclear duality of ciliates to analyse topological requirements for DNA replication and transcription

Taxonomic clarification of the dinophyte Peridinium acuminatum Ehrenb., ≡ Scrippsiella acuminata, comb. nov. (Thoracosphaeraceae, Peridiniales)

Dinophysiales (Dinophyceae) del Parque Nacional Sistema Arrecifal Veracruzano, Golfo de México, con clave para identificación

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