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Pesquisa : B01.043.185.650.375.550.637 [Categoria DeCS]
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  1 / 1970 MEDLINE  
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[PMID]:29287245
[Au] Autor:Sabaneyeva E; Castelli M; Szokoli F; Benken K; Lebedeva N; Salvetti A; Schweikert M; Fokin S; Petroni G
[Ad] Endereço:Department of Cytology and Histology, St. Petersburg State University, Russian Federation. Electronic address: e.sabaneeva@spbu.ru.
[Ti] Título:Host and symbiont intraspecific variability: The case of Paramecium calkinsi and "Candidatus Trichorickettsia mobilis".
[So] Source:Eur J Protistol;62:79-94, 2018 Feb.
[Is] ISSN:1618-0429
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Newly isolated strains of the ciliate Paramecium calkinsi and their cytoplasmic bacterial endosymbionts were characterized by a multidisciplinary approach, including live observation, ultrastructural investigation, and molecular analysis. Despite morphological resemblance, the characterized P. calkinsi strains showed a significant molecular divergence compared to conspecifics, possibly hinting for a cryptic speciation. The endosymbionts were clearly found to be affiliated to the species "Candidatus Trichorickettsia mobilis" (Rickettsiales, Rickettsiaceae), currently encompassing only bacteria retrieved in an obligate intracellular association with other ciliates. However, a relatively high degree of intraspecific divergence was observed as well, thus it was possible to split "Candidatus Trichorickettsia" into three subspecies, one of which represented so far only by the newly characterized endosymbionts of P. calkinsi. Other features distinguished the members of each different subspecies. In particular, the endosymbionts of P. calkinsi resided in the cytoplasm and possessed numerous peritrichous flagella, although no motility was evidenced, whereas their conspecifics in other hosts were either cytoplasmic and devoid of flagella, or macronuclear, displaying flagellar-driven motility. Moreover, contrarily to previously analyzed "Candidatus Trichorickettsia" hosts, infected P. calkinsi cells frequently became amicronucleate and demonstrated abnormal cell division, eventually leading to decline of the laboratory culture.
[Mh] Termos MeSH primário: Alphaproteobacteria/fisiologia
Interações Hospedeiro-Parasita
Paramecium/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171230
[St] Status:MEDLINE


  2 / 1970 MEDLINE  
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[PMID]:29360451
[Au] Autor:Xu J; Yang F; Han D; Xu S
[Ad] Endereço:Key Laboratory for the Physics & Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing, 100871, PR China.
[Ti] Título:Phenomena of synchronized response in biosystems and the possible mechanism.
[So] Source:Biochem Biophys Res Commun;496(2):661-666, 2018 02 05.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Phenomena of synchronized response is common among organs, tissues and cells in biosystems. We have analyzed and discussed three examples of synchronization in biosystems, including the direction-changing movement of paramecia, the prey behavior of flytraps, and the simultaneous discharge of electric eels. These phenomena and discussions support an electrical communication mechanism that in biosystems, the electrical signals are mainly soliton-like electromagnetic pulses, which are generated by the transient transmembrane ionic current through the ion channels and propagate along the dielectric membrane-based softmaterial waveguide network to complete synchronized responses. This transmission model implies that a uniform electrical communication mechanism might have been naturally developed in biosystem.
[Mh] Termos MeSH primário: Comunicação Animal
Fenômenos Eletrofisiológicos
Canais Iônicos/metabolismo
[Mh] Termos MeSH secundário: Animais
Membrana Celular/metabolismo
Eletricidade
Electrophorus/fisiologia
Transporte de Íons
Movimento
Paramecium/fisiologia
Sarraceniaceae/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Ion Channels)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180216
[Lr] Data última revisão:
180216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180124
[St] Status:MEDLINE


  3 / 1970 MEDLINE  
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[PMID]:28251922
[Au] Autor:Bright LJ; Gout JF; Lynch M
[Ad] Endereço:Department of Biology, Indiana University, Bloomington, IN 47405 lydjbright@gmail.com brightl@newpaltz.edu.
[Ti] Título:Early stages of functional diversification in the Rab GTPase gene family revealed by genomic and localization studies in species.
[So] Source:Mol Biol Cell;28(8):1101-1110, 2017 Apr 15.
[Is] ISSN:1939-4586
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:New gene functions arise within existing gene families as a result of gene duplication and subsequent diversification. To gain insight into the steps that led to the functional diversification of paralogues, we tracked duplicate retention patterns, expression-level divergence, and subcellular markers of functional diversification in the Rab GTPase gene family in three species. After whole-genome duplication, Rab GTPase duplicates are more highly retained than other genes in the genome but appear to be diverging more rapidly in expression levels, consistent with early steps in functional diversification. However, by localizing specific Rab proteins in cells, we found that paralogues from the two most recent whole-genome duplications had virtually identical localization patterns, and that less closely related paralogues showed evidence of both conservation and diversification. The functionally conserved paralogues appear to target to compartments associated with both endocytic and phagocytic recycling functions, confirming evolutionary and functional links between the two pathways in a divergent eukaryotic lineage. Because the functionally diversifying paralogues are still closely related to and derived from a clade of functionally conserved Rab11 genes, we were able to pinpoint three specific amino acid residues that may be driving the change in the localization and thus the function in these proteins.
[Mh] Termos MeSH primário: Paramecium/enzimologia
Paramecium/genética
Proteínas rab de Ligação ao GTP/genética
Proteínas rab de Ligação ao GTP/metabolismo
[Mh] Termos MeSH secundário: Animais
Evolução Biológica
Evolução Molecular
Duplicação Gênica
Genoma de Protozoário
Genômica
Filogenia
Transcriptoma
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 3.6.5.2 (rab GTP-Binding Proteins)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170714
[Lr] Data última revisão:
170714
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170303
[St] Status:MEDLINE
[do] DOI:10.1091/mbc.E16-06-0361


  4 / 1970 MEDLINE  
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[PMID]:28222239
[Au] Autor:Killeen J; Gougat-Barbera C; Krenek S; Kaltz O
[Ad] Endereço:Institut des Sciences de l'Evolution Montpellier, UMR5554, Université de Montpellier, CC065, Place E. Bataillon, 34095, Montpellier Cedex 5, France.
[Ti] Título:Evolutionary rescue and local adaptation under different rates of temperature increase: a combined analysis of changes in phenotype expression and genotype frequency in Paramecium microcosms.
[So] Source:Mol Ecol;26(7):1734-1746, 2017 Apr.
[Is] ISSN:1365-294X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Evolutionary rescue (ER) occurs when populations, which have declined due to rapid environmental change, recover through genetic adaptation. The success of this process and the evolutionary trajectory of the population strongly depend on the rate of environmental change. Here we investigated how different rates of temperature increase (from 23 to 32 °C) affect population persistence and evolutionary change in experimental microcosms of the protozoan Paramecium caudatum. Consistent with theory on ER, we found that those populations experiencing the slowest rate of temperature increase were the least likely to become extinct and tended to be the best adapted to the new temperature environment. All high-temperature populations were more tolerant to severe heat stress (35, 37 °C), indicating a common mechanism of heat protection. High-temperature populations also had superior growth rates at optimum temperatures, leading to the absence of a pattern of local adaptation to control (23 °C) and high-temperature (32 °C) environments. However, high-temperature populations had reduced growth at low temperatures (5-9 °C), causing a shift in the temperature niche. In part, the observed evolutionary change can be explained by selection from standing variation. Using mitochondrial markers, we found complete divergence between control and high-temperature populations in the frequencies of six initial founder genotypes. Our results confirm basic predictions of ER and illustrate how adaptation to an extreme local environment can produce positive as well as negative correlated responses to selection over the entire range of the ecological niche.
[Mh] Termos MeSH primário: Evolução Molecular
Paramecium/genética
Seleção Genética
Temperatura Ambiente
Termotolerância/genética
[Mh] Termos MeSH secundário: Genótipo
Fenótipo
Dinâmica Populacional
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170512
[Lr] Data última revisão:
170512
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170222
[St] Status:MEDLINE
[do] DOI:10.1111/mec.14068


  5 / 1970 MEDLINE  
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[PMID]:28204679
[Au] Autor:Johri P; Krenek S; Marinov GK; Doak TG; Berendonk TU; Lynch M
[Ad] Endereço:Department of Biology, Indiana University, Bloomington, IN.
[Ti] Título:Population Genomics of Paramecium Species.
[So] Source:Mol Biol Evol;34(5):1194-1216, 2017 May 01.
[Is] ISSN:1537-1719
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Population-genomic analyses are essential to understanding factors shaping genomic variation and lineage-specific sequence constraints. The dearth of such analyses for unicellular eukaryotes prompted us to assess genomic variation in Paramecium, one of the most well-studied ciliate genera. The Paramecium aurelia complex consists of ∼15 morphologically indistinguishable species that diverged subsequent to two rounds of whole-genome duplications (WGDs, as long as 320 MYA) and possess extremely streamlined genomes. We examine patterns of both nuclear and mitochondrial polymorphism, by sequencing whole genomes of 10-13 worldwide isolates of each of three species belonging to the P. aurelia complex: P. tetraurelia, P. biaurelia, P. sexaurelia, as well as two outgroup species that do not share the WGDs: P. caudatum and P. multimicronucleatum. An apparent absence of global geographic population structure suggests continuous or recent dispersal of Paramecium over long distances. Intergenic regions are highly constrained relative to coding sequences, especially in P. caudatum and P. multimicronucleatum that have shorter intergenic distances. Sequence diversity and divergence are reduced up to ∼100-150 bp both upstream and downstream of genes, suggesting strong constraints imposed by the presence of densely packed regulatory modules. In addition, comparison of sequence variation at non-synonymous and synonymous sites suggests similar recent selective pressures on paralogs within and orthologs across the deeply diverging species. This study presents the first genome-wide population-genomic analysis in ciliates and provides a valuable resource for future studies in evolutionary and functional genetics in Paramecium.
[Mh] Termos MeSH primário: DNA Mitocondrial/genética
Paramecium/genética
[Mh] Termos MeSH secundário: Animais
Evolução Molecular
Variação Genética/genética
Genoma de Protozoário/genética
Genômica
Metagenômica/métodos
Mutação
Filogenia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Mitochondrial)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170217
[St] Status:MEDLINE
[do] DOI:10.1093/molbev/msx074


  6 / 1970 MEDLINE  
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[PMID]:28068760
[Au] Autor:Gupta GS; Kumar A; Senapati VA; Pandey AK; Shanker R; Dhawan A
[Ad] Endereço:Division of Biological & Life Sciences, School of Arts & Sciences (Formerly, Institute of Life Sciences), Ahmedabad University , University Road, Navrangpura, Ahmedabad 380009, Gujarat, India.
[Ti] Título:Laboratory Scale Microbial Food Chain To Study Bioaccumulation, Biomagnification, and Ecotoxicity of Cadmium Telluride Quantum Dots.
[So] Source:Environ Sci Technol;51(3):1695-1706, 2017 Feb 07.
[Is] ISSN:1520-5851
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The increasing applications of engineered nanomaterials (ENMs) in consumer products warrant a careful evaluation of their trophic transfer and consequent ecological impact. In the present study, a laboratory scale aquatic microbial food chain was established using bacteria (Escherichia coli (E. coli)) as a prey and ciliated protozoan (Paramecium caudatum) as a predator organism to determine the impact of cadmium telluride quantum dots (CdTe QDs). We observed that 29% of bacterivory potential of paramecium was lost, including an ∼12 h delay in doubling time on exposure to 25 mg/L CdTe QD (∼4 nm) as compared to control. The fluorescence based stoichiometric analysis revealed that 65% of the QDs bioaccumulated when paramecia were exposed to 25 mg/L QDs at 24 h. There was a significant (p < 0.05) increase in cellular cadmium (Cd) concentration at 24 h (306 ± 192 mg/L) as compared to 1 h (152 ± 50 mg/L). Moreover, the accumulation of Cd in E. coli (147 ± 25 mg/L) at 1 h of exposure to 25 mg/L QDs transferred 1.4 times higher Cd (207 ± 24 mg/L; biomagnification factor = 1.4) to its predator, paramecium.
[Mh] Termos MeSH primário: Cadeia Alimentar
Pontos Quânticos/toxicidade
[Mh] Termos MeSH secundário: Cádmio/toxicidade
Compostos de Cádmio/toxicidade
Escherichia coli
Nanoestruturas
Paramecium
Telúrio/toxicidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cadmium Compounds); 00BH33GNGH (Cadmium); NQA0O090ZJ (Tellurium)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170609
[Lr] Data última revisão:
170609
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170111
[St] Status:MEDLINE
[do] DOI:10.1021/acs.est.6b03950


  7 / 1970 MEDLINE  
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[PMID]:27251227
[Au] Autor:Plattner H
[Ad] Endereço:Department of Biology, University of Konstanz, PO Box M625, 78457, Konstanz, Germany.
[Ti] Título:Trichocysts-Paramecium's Projectile-like Secretory Organelles: Reappraisal of their Biogenesis, Composition, Intracellular Transport, and Possible Functions.
[So] Source:J Eukaryot Microbiol;64(1):106-133, 2017 Jan.
[Is] ISSN:1550-7408
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:This review summarizes biogenesis, composition, intracellular transport, and possible functions of trichocysts. Trichocyst release by Paramecium is the fastest dense core-secretory vesicle exocytosis known. This is enabled by the crystalline nature of the trichocyst "body" whose matrix proteins (tmp), upon contact with extracellular Ca , undergo explosive recrystallization that propagates cooperatively throughout the organelle. Membrane fusion during stimulated trichocyst exocytosis involves Ca mobilization from alveolar sacs and tightly coupled store-operated Ca -influx, initiated by activation of ryanodine receptor-like Ca -release channels. Particularly, aminoethyldextran perfectly mimics a physiological function of trichocysts, i.e. defense against predators, by vigorous, local trichocyst discharge. The tmp's contained in the main "body" of a trichocyst are arranged in a defined pattern, resulting in crossstriation, whose period expands upon expulsion. The second part of a trichocyst, the "tip", contains secretory lectins which diffuse upon discharge. Repulsion from predators may not be the only function of trichocysts. We consider ciliary reversal accompanying stimulated trichocyst exocytosis (also in mutants devoid of depolarization-activated Ca channels) a second, automatically superimposed defense mechanism. A third defensive mechanism may be effectuated by the secretory lectins of the trichocyst tip; they may inhibit toxicyst exocytosis in Dileptus by crosslinking surface proteins (an effect mimicked in Paramecium by antibodies against cell surface components). Some of the proteins, body and tip, are glycosylated as visualized by binding of exogenous lectins. This reflects the biogenetic pathway, from the endoplasmic reticulum via the Golgi apparatus, which is also supported by details from molecular biology. There are fragile links connecting the matrix of a trichocyst with its membrane; these may signal the filling state, full or empty, before and after tmp release upon exocytosis, respectively. This is supported by experimentally produced "frustrated exocytosis", i.e. membrane fusion without contents release, followed by membrane resealing and entry in a new cycle of reattachment for stimulated exocytosis. There are some more puzzles to be solved: Considering the absence of any detectable Ca and of acidity in the organelle, what causes the striking effects of silencing the genes of some specific Ca -release channels and of subunits of the H -ATPase? What determines the inherent polarity of a trichocyst? What precisely causes the inability of trichocyst mutants to dock at the cell membrane? Many details now call for further experimental work to unravel more secrets about these fascinating organelles.
[Mh] Termos MeSH primário: Paramecium/fisiologia
[Mh] Termos MeSH secundário: Transporte Biológico
Biogênese de Organelas
Organelas/metabolismo
Organelas/fisiologia
Organelas/ultraestrutura
Paramecium/citologia
Paramecium/genética
Paramecium/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160603
[St] Status:MEDLINE
[do] DOI:10.1111/jeu.12332


  8 / 1970 MEDLINE  
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[PMID]:27992463
[Au] Autor:Lanzoni O; Fokin SI; Lebedeva N; Migunova A; Petroni G; Potekhin A
[Ad] Endereço:Department of Biology, University of Pisa, Pisa, Italy.
[Ti] Título:Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".
[So] Source:PLoS One;11(12):e0167928, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo: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.
[Mh] Termos MeSH primário: Chlorella/classificação
Água Doce/parasitologia
Holosporaceae/classificação
Paramecium/classificação
[Mh] Termos MeSH secundário: Chlorella/genética
Chlorella/isolamento & purificação
Citoplasma/química
DNA Ribossômico/análise
Holosporaceae/genética
Holosporaceae/isolamento & purificação
Macronúcleo/genética
Paramecium/genética
Paramecium/isolamento & purificação
Paramecium/microbiologia
Filogenia
RNA Ribossômico/análise
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Ribosomal); 0 (RNA, Ribosomal)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161220
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0167928


  9 / 1970 MEDLINE  
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[PMID]:27742680
[Au] Autor:Szokoli F; Castelli M; Sabaneyeva E; Schrallhammer M; Krenek S; Doak TG; Berendonk TU; Petroni G
[Ad] Endereço:Institut für Hydrobiologie, Technische Universität Dresden, Dresden, Germany.
[Ti] Título:Disentangling the Taxonomy of Rickettsiales and Description of Two Novel Symbionts ("Candidatus Bealeia paramacronuclearis" and "Candidatus Fokinia cryptica") Sharing the Cytoplasm of the Ciliate Protist Paramecium biaurelia.
[So] Source:Appl Environ Microbiol;82(24):7236-7247, 2016 Dec 15.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In the past 10 years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, IN. Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium "Candidatus Bealeia paramacronuclearis" occurs in clumps and is frequently associated with the host macronucleus. With its electron-dense cytoplasm and a distinct halo surrounding the cell, it is easily distinguishable from the second smaller symbiont, "Candidatus Fokinia cryptica," whose cytoplasm is electron lucid, lacks a halo, and is always surrounded by a symbiontophorous vacuole. For molecular characterization, the small-subunit rRNA genes were sequenced and used for taxonomic assignment as well as the design of species-specific oligonucleotide probes. Phylogenetic analyses revealed that "Candidatus Bealeia paramacronuclearis" clusters with the so-called "basal" Rickettsiales, and "Candidatus Fokinia cryptica" belongs to "Candidatus Midichloriaceae." We obtained tree topologies showing a separation of Rickettsiales into at least two groups: one represented by the families Rickettsiaceae, Anaplasmataceae, and "Candidatus Midichloriaceae" (RAM clade), and the other represented by "basal Rickettsiales," including "Candidatus Bealeia paramacronuclearis." Therefore, and in accordance with recent publications, we propose to limit the order Rickettsiales to the RAM clade and to raise "basal Rickettsiales" to an independent order, Holosporales ord. nov., inside Alphaproteobacteria, which presently includes four family-level clades. Additionally, we define the family "Candidatus Hepatincolaceae" and redefine the family Holosporaceae IMPORTANCE: In this paper, we provide the characterization of two novel bacterial symbionts inhabiting the same Paramecium host (Ciliophora, Alveolata). Both symbionts belong to "traditional" Rickettsiales, one representing a new species of the genus "Candidatus Fokinia" ("Candidatus Midichloriaceae"), and the other representing a new genus of a "basal" Rickettsiales According to newly characterized sequences and to a critical revision of recent literature, we propose a taxonomic reorganization of "traditional" Rickettsiales that we split into two orders: Rickettsiales sensu stricto and Holosporales ord. nov. This work represents a critical revision, including new records of a group of symbionts frequently occurring in protists and whose biodiversity is still largely underestimated.
[Mh] Termos MeSH primário: Alphaproteobacteria/isolamento & purificação
Citoplasma/microbiologia
Paramecium/microbiologia
Rickettsiaceae/isolamento & purificação
[Mh] Termos MeSH secundário: Alphaproteobacteria/classificação
Alphaproteobacteria/genética
Alphaproteobacteria/fisiologia
Paramecium/fisiologia
Filogenia
Rickettsiaceae/classificação
Rickettsiaceae/genética
Rickettsiaceae/fisiologia
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171107
[Lr] Data última revisão:
171107
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161016
[St] Status:MEDLINE


  10 / 1970 MEDLINE  
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[PMID]:27707864
[Au] Autor:Lodh S; Yano J; Valentine MS; Van Houten JL
[Ad] Endereço:Department of Biology, University of Vermont, Burlington, VT 05405, USA.
[Ti] Título:Voltage-gated calcium channels of Paramecium cilia.
[So] Source:J Exp Biol;219(Pt 19):3028-3038, 2016 Oct 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca entering the cilium through voltage-gated Ca (Ca ) channels that are found exclusively in the cilia. As ciliary Ca levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the Ca channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary Ca channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three Ca α1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary Ca channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of Ca channel activity do not express any of the three Ca 1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three Ca channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the Ca 1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia.
[Mh] Termos MeSH primário: Canais de Cálcio/metabolismo
Cílios/metabolismo
Paramecium/metabolismo
[Mh] Termos MeSH secundário: Sequência de Bases
Western Blotting
Canais de Cálcio/química
Sequência Consenso
Imunoprecipitação
Mutação/genética
Fenótipo
Ligação Proteica
Domínios Proteicos
Subunidades Proteicas/química
Subunidades Proteicas/metabolismo
Interferência de RNA
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Reação em Cadeia da Polimerase em Tempo Real
Coloração pela Prata
Soluções
Frações Subcelulares/metabolismo
Natação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Calcium Channels); 0 (Protein Subunits); 0 (RNA, Messenger); 0 (Solutions)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171001
[Lr] Data última revisão:
171001
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161007
[St] Status:MEDLINE



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