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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Primary endosymbiosis: have cyanobacteria and Chlamydiae ever been roommates?

100%
Deschamps P.
Acta Societatis Botanicorum Poloniae
|
2014
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tom 83
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nr 4
Eukaryotes acquired the ability to process photosynthesis by engulfing a cyanobacterium and transforming it into a genuine organelle called the plastid. This event, named primary endosymbiosis, occurred once more than a billion years ago, and allowed the emergence of the Archaeplastida, a monophyletic supergroup comprising the green algae and plants, the red algae and the glaucophytes. Of the other known cases of symbiosis between cyanobacteria and eukaryotes, none has achieved a comparable level of cell integration nor reached the same evolutionary and ecological success than primary endosymbiosis did. Reasons for this unique accomplishment are still unknown and difficult to comprehend. The exploration of plant genomes has revealed a considerable amount of genes closely related to homologs of Chlamydiae bacteria, and probably acquired by horizontal gene transfer. Several studies have proposed that these transferred genes, which are mostly involved in the functioning of the plastid, may have helped the settlement of primary endosymbiosis. Some of these studies propose that Chlamydiae and cyanobacterial symbionts coexisted in the eukaryotic host of the primary endosymbiosis, and that Chlamydiae provided solutions for the metabolic symbiosis between the cyanobacterium and the host, ensuring the success of primary endosymbiosis. In this review, I present a reevaluation of the contribution of Chlamydiae genes to the genome of Archaeplastida and discuss the strengths and weaknesses of this tripartite model for primary endosymbiosis.
2

Living together in the plankton: a survey of marine protist symbioses

100%
Anderson O. R.
Acta Protozoologica
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2014
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tom 53
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nr 1 Spec.is. Marine Heterotrophic Protists
3

Morphometrical characterization of green hydra symbiosis

84%
Kovacevic G., Horvatin K., Ljubesic N., Kalafatic M.
Folia Biologica
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2017
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tom 65
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nr 3
4

Achradina pulchra, a unique dinoflagellate (Amphilothales, Dinophyceae) with a radiolarian-like endoskeleton of celestite (strontium sulfate)

84%
Gomez F., Kiriakoulakis K., Lara E.
Acta Protozoologica
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2017
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tom 56
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nr 2
5

Aluminium deposition in hydras

84%
Kovacevic G., Kalafatic M., Horvatin K.
Folia Biologica
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2009
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tom 57
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nr 3-4
139-142
6

The acquisition of plastids/phototrophy in heterotrophic dinoflagellates

84%
Park M. G., Kim M., Kim S.
Acta Protozoologica
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2014
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tom 53
|
nr 1 Spec.is. Marine Heterotrophic Protists
7

Effects of norflurazon on green and brown hydra

84%
Kovacevic G., Kalafatic M., Ljubesic N.
Folia Biologica
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2009
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tom 57
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nr 1-2
91-96
8
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Unique genome evolution in an intracellular N2-fixing symbiont of a rhopalodiacean diatom

84%
Nakayama T., Inagaki Y.
Acta Societatis Botanicorum Poloniae
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2014
|
tom 83
|
nr 4
Cyanobacteria, the major photosynthetic prokaryotic lineage, are also known as a major nitrogen fixer in nature. N2-fixing cyanobacteria are frequently found in symbioses with various types of eukaryotes and supply fixed nitrogen compounds to their eukaryotic hosts, which congenitally lack N2-fixing abilities. Diatom species belonging to the family Rhopalodiaceae also possess cyanobacterial symbionts called spheroid bodies. Unlike other cyanobacterial N2-fixing symbionts, the spheroid bodies reside in the cytoplasm of the diatoms and are inseparable from their hosts. Recently, the first spheroid body genome from a rhopalodiacean diatom has been completely sequenced. Overall features of the genome sequence showed significant reductive genome evolution resulting in a diminution of metabolic capacity. Notably, despite its cyanobacterial origin, the spheroid body was shown to be truly incapable of photosynthesis implying that the symbiont energetically depends on the host diatom. The comparative genome analysis between the spheroid body and another N2-fixing symbiotic cyanobacterial group corresponding to the UCYN-A phylotypes – both were derived from cyanobacteria closely related to genus Cyanothece – revealed that the two symbionts are on similar, but explicitly distinct tracks of reductive evolution. Intimate symbiotic relationships linked by nitrogen fixation as seen in rhopalodiacean diatoms may help us better understand the evolution and mechanisms of bacterium-eukaryote endosymbioses.
9
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Plastid origin: who, when and why?

84%
Ku C., Roettger M., Zimorski V., Nelsen-Sathi S., Sousa F. L., Martin W. F.
Acta Societatis Botanicorum Poloniae
|
2014
|
tom 83
|
nr 4
The origin of plastids is best explained by endosymbiotic theory, which dates back to the early 1900s. Three lines of evidence based on protein import machineries and molecular phylogenies of eukaryote (host) and cyanobacterial (endosymbiont) genes point to a single origin of primary plastids, a unique and important event that successfully transferred two photosystems and oxygenic photosynthesis from prokaryotes to eukaryotes. The nature of the cyanobacterial lineage from which plastids originated has been a topic of investigation. Recent studies have focused on the branching position of the plastid lineage in the phylogeny based on cyanobacterial core genes, that is, genes shared by all cyanobacteria and plastids. These studies have delivered conflicting results, however. In addition, the core genes represent only a very small portion of cyanobacterial genomes and may not be a good proxy for the rest of the ancestral plastid genome. Information in plant nuclear genomes, where most genes that entered the eukaryotic lineage through acquisition from the plastid ancestor reside, suggests that heterocyst-forming cyanobacteria in Stanier’s sections IV and V are most similar to the plastid ancestor in terms of gene complement and sequence conservation, which is in agreement with models suggesting an important role of nitrogen fixation in symbioses involving cyanobacteria. Plastid origin is an ancient event that involved a prokaryotic symbiont and a eukaryotic host, organisms with different histories and genome evolutionary processes. The different modes of genome evolution in prokaryotes and eukaryotes bear upon our interpretations of plastid phylogeny.
10

Complete elimination of endosymbiotic algae from Paramecium bursaria and its confirmation by diagnostic PCR

84%
Tanaka M., Murata-Hori M., Kadono T., Yamada T., Kawano T., Kosaka T., Hosoya H.
Acta Protozoologica
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2002
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tom 41
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nr 3
11

The eukaryotic genome: patchwork of a complex phylogenetic puzzle

84%
Herrmann R. G.
Biological Letters
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2005
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tom 42
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nr 2 Spec.Vol.
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Protein translocons in photosynthetic organelles of Paulinella chromatophora

67%
Gagat P., Mackiewicz P.
Acta Societatis Botanicorum Poloniae
|
2014
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tom 83
|
nr 4
The rhizarian amoeba Paulinella chromatophora harbors two photosynthetic cyanobacterial endosymbionts (chromatophores), acquired independently of primary plastids of glaucophytes, red algae and green plants. These endosymbionts have lost many essential genes, and transferred substantial number of genes to the host nuclear genome via endosymbiotic gene transfer (EGT), including those involved in photosynthesis. This indicates that, similar to primary plastids, Paulinella endosymbionts must have evolved a transport system to import their EGT-derived proteins. This system involves vesicular trafficking to the outer chromatophore membrane and presumably a simplified Tic-like complex at the inner chromatophore membrane. Since both sequenced Paulinella strains have been shown to undergo differential plastid gene losses, they do not have to possess the same set of Toc and Tic homologs. We searched the genome of Paulinella FK01 strain for potential Toc and Tic homologs, and compared the results with the data obtained for Paulinella CCAC 0185 strain, and 72 cyanobacteria, eight Archaeplastida as well as some other bacteria. Our studies revealed that chromatophore genomes from both Paulinella strains encode the same set of translocons that could potentially create a simplified but fully-functional Tic-like complex at the inner chromatophore membranes. The common maintenance of the same set of translocon proteins in two Paulinella strains suggests a similar import mechanism and/or supports the proposed model of protein import. Moreover, we have discovered a new putative Tic component, Tic62, a redox sensor protein not identified in previous comparative studies of Paulinella translocons.
13
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Paulinella chromatophora - rethinking the transition from endosymbiont to organelle

67%
Nowack E. C. M.
Acta Societatis Botanicorum Poloniae
|
2014
|
tom 83
|
nr 4
Eukaryotes co-opted photosynthetic carbon fixation from prokaryotes by engulfing a cyanobacterium and stably integrating it as a photosynthetic organelle (plastid) in a process known as primary endosymbiosis. The sheer complexity of interactions between a plastid and the surrounding cell that started to evolve over 1 billion years ago, make it challenging to reconstruct intermediate steps in organelle evolution by studying extant plastids. Recently, the photosynthetic amoeba Paulinella chromatophora was identified as a much sought-after intermediate stage in the evolution of a photosynthetic organelle. This article reviews the current knowledge on this unique organism. In particular it describes how the interplay of reductive genome evolution, gene transfers, and trafficking of host-encoded proteins into the cyanobacterial endosymbiont contributed to transform the symbiont into a nascent photosynthetic organelle. Together with recent results from various other endosymbiotic associations a picture emerges that lets the targeting of host-encoded proteins into bacterial endosymbionts appear as an early step in the establishment of an endosymbiotic relationship that enables the host to gain control over the endosymbiont.
14

An endosymbiotic Trichonid, Trichodina rhinobatae sp. n. [Ciliophora: Petrichia] found in the Lesser guitarfish, Rhinobatos annulatus Smith, 1841 [Rajiformes: Rhinobatidae] from the South African Coast

67%
Van As J., Basson L.
Acta Protozoologica
|
1996
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tom 35
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nr 1
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