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1.
Zootaxa ; 4942(2): zootaxa.4942.2.9, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33757071

RESUMO

Anteholosticha sigmoidea (Foissner, 1982) Berger, 2003 was isolated from a wet soil sample collected on King George Island, Antarctica. Morphological observations and molecular phylogenetic analyses based on the gene sequences of small subunit ribosomal RNA (18S rRNA) were used to identify the species. Anteholosticha sigmoidea can be divided into two groups: group I (three populations described by Foissner 1982) and group II (described by Foissner 1984) based on the morphological differences. Group I differs from group II by the length of the midventral complex (65.1% vs. 52.5% of the cell length), the number of adoral membranelles (25-28 vs. 16-24), and the number of dorsal bristles in kinety 1 (16 bristles vs. nine bristles). Group I differs from the Antarctica population by the absence/presence of the collecting canals of the contractile vacuole and the number of macronuclear nodules (6-12 vs. 13-19). Group II differs from the Antarctica population by the number of macronuclear nodules (five to nine vs. 13-19); the arrangement of cortical granules (forming longitudinal rows vs. irregularly distributed); the length of the midventral complex (64.7% vs. 53.8% of cell length). In the phylogenetic analyses, A. sigmoidea was not nested with any species, and the gene tree indicated polyphyly of the genus Anteholosticha.


Assuntos
Cilióforos , Animais , Regiões Antárticas , Cilióforos/genética , DNA de Protozoário , Filogenia , RNA Ribossômico 18S/genética
2.
Exp Parasitol ; 223: 108081, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549536

RESUMO

Artificial breeding of small yellow croaker (Larimichthys polyactis) was recently achieved, providing a bright future for its commercial farming. In May 2019, a disease outbreak occurred among small yellow croakers in an aquaculture farm near Xiangshan Bay, charactering by white spots spotted on the surface of fish skin, gills and fins. The parasite was preliminarily identified as Cryptocaryon irritans based on morphological feature of the parasite and the symptoms on fish. However, the previously published specific primer pairs failed to confirm the existence of C. iriitans. Six nucleotides mismatches were discovered after mapping specific forward primer back to targeted gene. Therefore, an updated PCR specific primer was developed within the 9th highly variable region of 18S rRNA gene and conserved in all C. irritans sequences available in GenBank database. The specificity was verified in silico by Primer-BLAST against GenBank nucleotide. Laboratory cultured ciliates (Mesanophrys, Pseudokeronopsis and Uronema) as well as natural microbial community samples collected from sea water and river water was used as negative control to verify the specificity of the primer in situ. Besides, tank transfer method was used to evaluate the treatment of the parasite infection. By tank transfer method, 2.00 ± 0.61 out of 10 fish that already sever infected were successfully survived after 8 days treatment, meanwhile the control group died out at d 6. More loss to the treatment group during first five days was observed and may attribute to the combined effect from infection and stress the recent domesticated fish suffered during rotation. Therefore, tank transfer method was also effective to prevent small yellow croaker from further infection, however the loss of the small yellow croaker suffered from stress during rotation also needs to be carefully concerned. In conclusion, this study reported the first diagnose of C. irritans infection on small yellow croaker, provided updated specific primer to detect C. irritans infection on fish body and reported the effect of tank transfer on small yellow croaker treatment.


Assuntos
Infecções por Cilióforos/veterinária , Cilióforos/isolamento & purificação , Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Nadadeiras de Animais/parasitologia , Nadadeiras de Animais/patologia , Animais , China/epidemiologia , Cilióforos/classificação , Cilióforos/genética , Infecções por Cilióforos/diagnóstico , Infecções por Cilióforos/epidemiologia , Infecções por Cilióforos/parasitologia , Surtos de Doenças/veterinária , Doenças dos Peixes/diagnóstico , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/terapia , Pesqueiros , Brânquias/parasitologia , Brânquias/patologia , Músculo Esquelético/parasitologia , Músculo Esquelético/patologia , Filogenia , RNA Ribossômico 18S/genética , Pele/parasitologia , Pele/patologia , Especificidade da Espécie
3.
Eur J Protistol ; 78: 125769, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549969

RESUMO

A little-known haptorid ciliate, Helicoprorodon multinucleatum Dragesco, 1960, was found in a sandy beach at Qingdao, China. Its morphology was studied based on microscopic observations of live and protargol-stained specimens and morphometrics, and the phylogeny was analyzed using SSU rRNA gene sequences. Helicoprorodon multinucleatum is characterized by the combination of the following features: (i) a very narrowly worm-like body with a size of about 300-1500 µm × 30-60 µm in vivo, and two circles of horn-like protuberances around the head; (ii) 50-160 spherical macronuclear nodules scattered throughout the body; (iii) rod-shaped, 10-50 µm long extrusomes gathered into several bunches, which are randomly distributed beneath pellicle; and (iv) 42-88 somatic kineties, including four oralized kineties and two dorsal brush rows. Phylogenetic analyses reveal that both the family Helicoprorodontidae and the genus Helicoprorodon might be monophyletic. In addition, we provide an illustrated key to the species and the geographical distribution of the genus Helicoprorodon.


Assuntos
Cilióforos/classificação , Filogenia , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
4.
Eur J Protistol ; 78: 125768, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549970

RESUMO

In a study of marine ciliate diversity, we collected an Anteholosticha monilata-like population from Vietnam. To identify this population, we analyzed its morphology, some morphogenetic stages, and molecular phylogeny. Based on these data, we conclude that the Vietnamese population is new to science. Anteholosticha foissneri n. sp. resembles Anteholosticha monilata-like species considering (1) the number and arrangement of macronuclear nodules and micronuclei; (2) the presence of cortical granules; and (3) the saline habitat. However, the new species can be easily distinguished from these species by the arrangement, color, and shape of the cortical granules. The divisional morphogenesis commences with the de novo proliferation of basal bodies as a single longitudinal patch left of the posteriormost midventral cirral pair. This character state has not been reported before in Anteholosticha (based on check of the available data) and probably reflects a distinct clade within the nuclear small subunit ribosomal RNA gene tree.


Assuntos
Cilióforos/classificação , Morfogênese , Filogenia , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie , Vietnã
5.
Gene ; 767: 145186, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32998045

RESUMO

In ciliates, with every sexual event the transcriptionally active genes of the sub-chromosomic somatic genome that resides in the cell macronucleus are lost. They are de novo assembled starting from 'Macronuclear Destined Sequences' that arise from the fragmentation of transcriptionally silent DNA sequences of the germline chromosomic genome enclosed in the cell micronucleus. The RNA-mediated epigenetic mechanism that drives the assembly of these sequences is subject to errors which result in the formation of chimeric genes. Studying a gene family that in Euplotes raikovi controls the synthesis of protein signal pheromones responsible for a self/not-self recognition mechanism, we identified the chimeric structure of an 851-bp macronuclear gene previously known to specify soluble and membrane-bound pheromone molecules through an intron-splicing mechanism. This chimeric gene, designated mac-er-1*, conserved the native pheromone-gene structure throughout its coding and 3' regions. Instead, its 5' region is completely unrelated to the pheromone gene structure at the level of a 360-bp sequence, which derives from the assembly with a MDS destined to compound a 2417-bp gene encoding a 696-amino acid protein with unknown function. This mac-er-1* gene characterization provides further evidence that ciliates rely on functional chimeric genes that originate in non-programmed phenomena of somatic MDS recombination to increase the species genetic variability independently of gene reshuffling phenomena of the germline genome.


Assuntos
Quimera/genética , Euplotes/genética , Feromônios/genética , Sequência de Aminoácidos/genética , Sequência de Bases/genética , Cilióforos/genética , DNA/genética , Rearranjo Gênico/genética , Íntrons/genética , RNA/genética , Processamento de RNA/genética
6.
Protist ; 171(4): 125752, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32814281

RESUMO

The genus Psilotricha was established by Stein in 1859, with P. acuminata as the type species within the family Oxytrichidae. This species lacked a full description until it was re-discovered in 2001, showing that its morphological and morphogenetic characters confirmed the inclusion in the family Oxytrichidae. Since then, the genus Psilotricha has had a convoluted taxonomy despite the morphological evidence available. In this paper, we describe a new Psilotricha species, Psilotricha silvicola n. sp., from woodland soils in Southern England (United Kingdom). The morphology was investigated in live and protargol-impregnated specimens. Our findings show that P. silvicola n. sp. shares morphological characteristics with P. acuminata, including the distinctive cell shape and the long and sparse cirri. Phylogenetic analysis of the 18S rRNA gene places this new species within the family Oxytrichidae, nested apart from the family Psilotrichidae (which includes the genera Urospinula, Psilotrichides and Hemiholosticha), in a clade containing species of the family Oxytrichidae. Furthermore, the morphology of another Psilotricha species, P. viridis, found in a freshwater pond in the same woodland area, is also here described, bringing additional insight into the taxonomy of the genus. Our findings provide further evidence for inclusion of the genus Psilotricha within the oxytrichids.


Assuntos
Cilióforos/classificação , Solo/parasitologia , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , Florestas , Água Doce , Filogenia , RNA Ribossômico 18S/genética , Especificidade da Espécie , Reino Unido
7.
PLoS One ; 15(8): e0238167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857792

RESUMO

The ciliated protozoan Cryptocaryon irritans infects a wide range of marine fish and causes the highly lethal white spot disease. This parasite possesses three morphologically and physiologically distinct life stages: an infectious theront, a parasitic trophont, and an asexually reproductive tomont. In the past few years, several attempts have been made to help elucidate how C. irritans transforms from one stage to another using transcriptomic or proteomic approaches. However, there has been no research studying changes in transcription profiles between different time points of a single C. irritans life stage-the development of this parasite. Here we use RNA-seq and compare gene expression profiles of theront cells collected by 1 and 10 hrs after they emerged from tomonts. It has been shown that infectivity of theront cells declines 6-8 hours post-emergence, and we used this characteristic as a physiological marker to confirm the aging of theront cells. We identified a total of 41 upregulated and 90 downregulated genes that were differentially expressed between young and aging theront cells. Using Blast2Go to further analyze functions of these genes, we show that genes related to energy production are downregulated, but quite surprisingly many genes involved in transcription/translation processes are upregulated. We also show that expression of all nine detectable agglutination/immobilization antigen genes, with great sequence divergence, is invariably downregulated. Functions of other differentially expressed genes and indications are also discussed in our study.


Assuntos
Envelhecimento/metabolismo , Cilióforos/metabolismo , Cilióforos/patogenicidade , Animais , Cilióforos/genética , Cilióforos/crescimento & desenvolvimento , Infecções por Cilióforos/veterinária , Doenças dos Peixes/parasitologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Perciformes , Análise de Sequência de RNA , Transcriptoma
8.
Protist ; 171(4): 125755, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32858402

RESUMO

The systematics of Hypotricha is one of the most puzzling problems in ciliate biology, having spanned numerous conflicting hypotheses with unstable relationships at various levels in molecular trees, for which the constant addition of newly discovered species has only increased the confusion. The hypotrichs comprise a remarkable morphologically diversified group of ciliates, and the phylogenetic potential of morphological traits is generally recognized. However, such characters were rarely used in phylogenetic reconstructions, and congruence with molecular data never assessed from simultaneous analyses. To properly reconciliate morphological and molecular information, maximum-likelihood and parsimony analyses of 79 morphological characters and 18S rDNA sequences were performed for 130 ingroup terminals, broadly sampled to represent the known hypotrich diversity. As result, well-supported and relatively stable clades were recovered, based on which the redefined Hypotricha comprises at least six higher taxa: The "arcuseriids", Holostichida, Parabirojimida, and the "amphisiellids", plus the two large clades Kentrurostylida nov. tax. (Hispidotergida nov. tax. and Simplicitergida nov. tax.) and Diatirostomata nov. tax. ("bistichellids", "kahliellids", Gonostomatida and Dorsomarginalia [Postoralida nov. tax. and Uroleptida]). Each taxon was circumscribed by synapomorphies, of which most were homoplastic, as the natural history of hypotrichs is portrayed by an outstanding quantity of convergences and reversions.


Assuntos
Cilióforos/classificação , Filogenia , Cilióforos/citologia , Cilióforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
9.
BMC Evol Biol ; 20(1): 86, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32677880

RESUMO

BACKGROUND: Although phylogenomic analyses are increasingly used to reveal evolutionary relationships among ciliates, relatively few nuclear protein-coding gene markers have been tested for their suitability as candidates for inferring phylogenies within this group. In this study, we investigate the utility of the heat-shock protein 90 gene (Hsp90) as a marker for inferring phylogenetic relationships among hypotrich ciliates. RESULTS: A total of 87 novel Hsp90 gene sequences of 10 hypotrich species were generated. Of these, 85 were distinct sequences. Phylogenetic analyses based on these data showed that: (1) the Hsp90 gene amino acid trees are comparable to the small subunit rDNA tree for recovering phylogenetic relationships at the rank of class, but lack sufficient phylogenetic signal for inferring evolutionary relationships at the genus level; (2) Hsp90 gene paralogs are recent and therefore unlikely to pose a significant problem for recovering hypotrich clades; (3) definitions of some hypotrich orders and families need to be revised as their monophylies are not supported by various gene markers; (4) The order Sporadotrichida is paraphyletic, but the monophyly of the "core" Urostylida is supported; (5) both the subfamily Oxytrichinae and the genus Urosoma seem to be non-monophyletic, but monophyly of Urosoma is not rejected by AU tests. CONCLUSIONS: Our results for the first time demonstrate that the Hsp90 gene is comparable to SSU rDNA for recovering phylogenetic relationships at the rank of class, and its paralogs are unlikely to pose a significant problem for recovering hypotrich clades. This study shows the value of careful gene marker selection for phylogenomic analyses of ciliates.


Assuntos
Cilióforos/genética , Evolução Molecular , Proteínas de Choque Térmico HSP90/genética , Sequência de Aminoácidos , Sequência de Bases , Cilióforos/classificação , DNA Ribossômico/genética , Bases de Dados Genéticas , Bases de Dados de Proteínas , Proteínas de Choque Térmico HSP90/química , Filogenia
10.
Arch Microbiol ; 202(7): 1861-1872, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448959

RESUMO

In addition to a wide variety of anaerobic and facultative anaerobic bacteria, camel rumen also harbors a diverse of eukaryotic organisms. In the present study, the eukaryotic communities of camel rumen were characterized using 18S rRNA amplicon sequencing. Metagenomic DNA was isolated from rumen samples of fourteen adult Bikaneri and Kachchhi breeds of camel fed different diets containing Jowar, Bajra, Maize, and Guar. Illumina sequencing generated 27,161,904 number of reads corresponding to 1543 total operational taxonomic units (OTUs). Taxonomic classification of community metagenome sequences from all the samples revealed the presence of 92 genera belonging to 16 different divisions, out of which Ciliophora (73%), Fungi (13%) and Streptophyta (9%) were found to be the most dominant. Notably, the abundance of Ciliophora was significantly higher in the case of Guar feed, while Fungi was significantly higher in the case of Maize feed, indicating the influence of cellulose and hemicellulose content of feedstuff on the composition of eukaryotes. The results suggest that the camel rumen eukaryotes are highly dynamic and depend on the type of diet given to the animal. Pearson's correlation analysis suggested the ciliate protozoa and fungi were negatively correlated with each other. To the best of our knowledge, this is first systematic study to characterize camel rumen eukaryotes, which has provided newer information regarding eukaryotic diversity patterns amongst camel fed on different diets.


Assuntos
Camelus/microbiologia , Camelus/parasitologia , Cilióforos , Dieta , Fungos , Rúmen/microbiologia , Rúmen/parasitologia , Animais , Cilióforos/classificação , Cilióforos/genética , Fungos/classificação , Fungos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Metagenoma , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
11.
Cell Mol Life Sci ; 77(22): 4615-4629, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32462406

RESUMO

Ciliates are a highly divergent group of unicellular eukaryotes with separate somatic and germline genomes found in distinct dimorphic nuclei. This characteristic feature is tightly linked to extremely laborious developmentally regulated genome rearrangements in the development of a new somatic genome/nuclei following sex. The transformation from germline to soma genome involves massive DNA elimination mediated by non-coding RNAs, chromosome fragmentation, as well as DNA amplification. In this review, we discuss the similarities and differences in the genome reorganization processes of the model ciliates Paramecium and Tetrahymena (class Oligohymenophorea), and the distantly related Euplotes, Stylonychia, and Oxytricha (class Spirotrichea).


Assuntos
Cilióforos/genética , Rearranjo Gênico/genética , Genoma de Protozoário/genética , Animais , Núcleo Celular/genética , Células Germinativas/fisiologia , Humanos
12.
Sci Rep ; 10(1): 3763, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111909

RESUMO

An integrated approach considering both morphologic and molecular data is now required to improve biodiversity estimations and provide more robust systematics interpretations in hypotrichs, a highly differentiated group of ciliates. In present study, we document a new hypotrich species, Lamtostyla gui n. sp., collected from Chongming wetland, Shanghai, China, based on investigations using living observation, protargol staining, scanning and transmission electron microscopy, and gene sequencing. The new species is mainly recognized by having a short amphisiellid median cirral row composed of four cirri, three frontoventral cirri, three dorsal kinetids, four to eight macronuclear nodules, and small colorless cortical granules distributed as rosettes around dorsal bristles. Transmission electron microscope observation finds the associated microtubules of cirri and pharyngeal discs of L. gui are distinct from those in other hypotrichs. Morphogenesis of this species indicates that parental adoral membranelles retained intact or partial renewed is a potential feature to separate Lamtostyla granulifera-group and Lamtostyla lamottei-group. Phylogenetic analysis based on small subunit ribosomal RNA (rRNA) gene shows that this molecular marker is not useful to resolve phylogenetic relationships of the genus Lamtostyla, as well as many other hypotrichous taxa. We additionally characterize the internal transcribed spacers (ITS) region and the almost complete large subunit rRNA, which will be essential for future studies aimed at solving phylogenetic problems of Lamtostyla, or even the family Amphisiellidae. As a final remark, the critical screening of GenBank using ITS genes of our organism allows us to recognize a large amount of hypotrichous sequences have been misclassified as fungi. This observation suggests that hypotrichs could be frequently found in fungi-rich environment and overlooked by fungal specialists.


Assuntos
Cilióforos/classificação , Cilióforos/genética , Filogenia , RNA Ribossômico/genética , Cilióforos/ultraestrutura
13.
Eur J Protistol ; 74: 125692, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32199082

RESUMO

The morphogenesis and molecular phylogeny of two soil hypotrich ciliates, Australocirrus australis and A. aspoecki, collected from Xi'an, Shaanxi Province, China, were investigated using protargol preparation. The main features of morphogenesis of A. australis are as follows: (1) the parental adoral zone of membranelles is retained completely in the proter; (2) parental cirri and the undulating membranes are involved in the formation of six primordial streaks; (3) multiple fragmentation of the third dorsal kinety anlage; (4) more than three dorsomarginal kineties are formed. An early divider of A. aspoecki was also found, and its morphogenetic events resemble those of other Australocirrus species. Furthermore, the SSU rDNA sequence of the Shaanxi populations of A. australis and A. aspoecki was provided. The molecular phylogeny indicates that A. aspoecki clusters together with A. rubrus and two populations of A. australis with full support, which are separated from the clade comprising the two populations of A. shii.


Assuntos
Cilióforos/classificação , Cilióforos/genética , Filogenia , Solo/parasitologia , Cilióforos/citologia , DNA de Protozoário/genética
14.
BMC Evol Biol ; 20(1): 37, 2020 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171235

RESUMO

BACKGROUND: Various ecological groups of earthworms very likely constitute sharply isolated niches that might permit speciation of their symbiotic ciliates, even though no distinct morphological features appear to be recognizable among ciliates originating from different host groups. The nuclear highly variable ITS1-5.8S-ITS2 region and the hypervariable D1/D2 region of the 28S rRNA gene have proven to be useful tools for the delimitation of species boundaries in closely related free-living ciliate taxa. In the present study, the power of these molecular markers as well as of the secondary structure of the ITS2 molecule were tested for the first time in order to discriminate the species of endosymbiotic ciliates that were isolated from the gastrointestinal tract of three ecologically different groups of lumbricid earthworms. RESULTS: Nineteen new ITS1-5.8S-ITS2 region and D1/D2-28S rRNA gene sequences were obtained from five astome species (Anoplophrya lumbrici, A. vulgaris, Metaradiophrya lumbrici, M. varians, and Subanoplophrya nodulata comb. n.), which were living in the digestive tube of three ecological groups of earthworms. Phylogenetic analyses of the rRNA locus and secondary structure analyses of the ITS2 molecule robustly resolved their phylogenetic relationships and supported the distinctness of all five species, although previous multivariate morphometric analyses were not able to separate congeners in the genera Anoplophrya and Metaradiophrya. The occurrence of all five taxa, as delimited by molecular analyses, was perfectly correlated with the ecological groups of their host earthworms. CONCLUSIONS: The present study indicates that morphology-based taxonomy of astome ciliates needs to be tested in the light of molecular and ecological data as well. The use of morphological identification alone is likely to miss species that are well delimited based on molecular markers and ecological traits and can lead to the underestimation of diversity and overestimation of host range. An integrative approach along with distinctly increased taxon sampling would be helpful to assess the consistency of the eco-evolutionary trend in astome ciliates.


Assuntos
Cilióforos/classificação , Cilióforos/isolamento & purificação , DNA Espaçador Ribossômico/genética , Trato Gastrointestinal/parasitologia , Oligoquetos/parasitologia , RNA Ribossômico 28S/genética , Animais , Cilióforos/genética , DNA Espaçador Ribossômico/análise , Ecologia , Genes de RNAr/genética , Interações Hospedeiro-Parasita/fisiologia , Oligoquetos/classificação , Oligoquetos/genética , Filogenia , RNA Ribossômico , RNA Ribossômico 28S/análise , Análise de Sequência de DNA
15.
Protist ; 171(2): 125716, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32086115

RESUMO

The genus Parablepharisma Jankowski, 2007 at present includes five species, most of which have not been studied in detail, therefore phylogenetic affinities remained uninvestigated up to now. Parablepharisma is traditionally placed within Heterotrichea based on insufficient existing morphological data, and there are no available Parablepharisma gene sequences in molecular databases to support this placement. This work presents an 18S rDNA-based phylogeny of P. bacteriophora (Kahl, 1932) Jankowski, 2007 and P. brasiliensis sp. nov. We also provide a redescription of P. bacteriophora and P. chlamydophorum (Kahl, 1932) Jankowski, 2007 based on live morphological observations combined with silver impregnation and scanning and transmission electron microscopy. According to characters such as macro- and micronucleus number, the position of the ectosymbiotic bacteria, and the presence/absence of caudal cilia, two new species are described, i.e. P. granulata sp. nov. and P. brasiliensis sp. nov. In addition, we establish Kahlium gen. nov. to include P. chlamydophorum, which has a segmented anterior paroral portion and a twisted posterior paroral section as diagnostic features. To include Parablepharisma and Kahlium gen. nov., we propose Parablepharismidae fam. nov. According to our phylogenetic analyses, Parablepharisma belongs to SAL (Spirotrichea, Armophorea, Litostomatea), being a sister group of Cariacotrichea.


Assuntos
Cilióforos , Filogenia , Cilióforos/classificação , Cilióforos/citologia , Cilióforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
16.
Eur J Protistol ; 73: 125669, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31931380

RESUMO

In a study on ciliate diversity, we discovered the new hypotrich species, Gonostomum jangbogoensis n. sp., in freshwater from Terra Nova Bay, Victoria Land, southeast Antarctica. We describe its morphology and morphogenesis using standard methods, and the SSU rRNA gene phylogeny is provided as well. Morphology of Gonostomum jangbogoensis n. sp. is characterized as follows: slender to elongated body shape; grayish under low magnification; cortical granules present; 32-41 adoral membranelles; 3 enlarged frontal cirri; 1 buccal cirrus; 2 frontoterminal cirri; 3 or 4 frontoventral cirral pairs, 2 pretransverse cirri, 6-7 transverse cirri; 13-19 left and 18-26 right marginal cirri; 17-23 paroral kinetids; 3 dorsal kineties; 3 caudal cirri; 2 macronuclear nodules with 1-3 micronuclei. The morphogenesis of the new species confirms that it has at least seven frontal-ventral-transverse cirral anlagen, which is also reported in Gonostomum sp. 1 sensu Shin from Korea. Even though these two populations occur very far from each other, the morphometric data prove that this character state, the seven cirral anlagen, is a stable feature across these populations and might be an apomorphy. The phylogenetic analyses show that the genus Gonostomum is non-monophyletic and that the new species is a sister to G. bromelicola.


Assuntos
Cilióforos/classificação , Morfogênese , Filogenia , Regiões Antárticas , Cilióforos/citologia , Cilióforos/genética , DNA Ribossômico/genética , Água Doce , Especificidade da Espécie
17.
ISME J ; 14(4): 984-998, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31919469

RESUMO

Marine sediments are one of the largest carbon reservoir on Earth, yet the microbial communities, especially the eukaryotes, that drive these ecosystems are poorly characterised. Here, we report implementation of a sampling system that enables injection of reagents into sediments at depth, allowing for preservation of RNA in situ. Using the RNA templates recovered, we investigate the 'ribosomally active' eukaryotic diversity present in sediments close to the water/sediment interface. We demonstrate that in situ preservation leads to recovery of a significantly altered community profile. Using SSU rRNA amplicon sequencing, we investigated the community structure in these environments, demonstrating a wide diversity and high relative abundance of stramenopiles and alveolates, specifically: Bacillariophyta (diatoms), labyrinthulomycetes and ciliates. The identification of abundant diatom rRNA molecules is consistent with microscopy-based studies, but demonstrates that these algae can also be exported to the sediment as active cells as opposed to dead forms. We also observe many groups that include, or branch close to, osmotrophic-saprotrophic protists (e.g. labyrinthulomycetes and Pseudofungi), microbes likely to be important for detrital decomposition. The sequence data also included a diversity of abundant amplicon-types that branch close to the Fonticula slime moulds. Taken together, our data identifies additional roles for eukaryotic microbes in the marine carbon cycle; where putative osmotrophic-saprotrophic protists represent a significant active microbial-constituent of the upper sediment layer.


Assuntos
Sequestro de Carbono , Sedimentos Geológicos/microbiologia , Microbiota , Biodiversidade , Cilióforos/genética , Filogenia , Água do Mar/microbiologia , Estramenópilas
18.
Eur J Protistol ; 72: 125663, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869711

RESUMO

In this study, we investigated the morphology and molecular phylogeny of four marine or brackish spirotrichean ciliates found in China, namely: Caryotricha sinica sp. nov., Prodiscocephalus orientalis sp. nov., P. cf. borrori, and Certesia quadrinucleata. Caryotricha sinica is characterized by its small size, seven cirral rows extending posteriorly to about 65% of the cell length, and four transverse cirri. Prodiscocephalus orientalis differs from its congeners mainly by the number of cirri in the "head" region and on the ventral side. The SSU rDNA sequence of P. cf. borrori differs from that of other population of P. borrori by ca. 40 bp. Consequently, the nominal species P. borrori is considered to be a species-complex. New data are provided for Certesia quadrinucleata. The Chinese population of C. quadrinucleata, for example, has fewer left marginal cirri than the other populations for which such data are available. Phylogenetic analyses based on SSU rDNA sequence data show that the genus Caryotricha is monophyletic. All typical "discocephalids" with a discoid "head" form a strongly supported clade that is sister to the unstable uronychiids + pseudoamphisiellids clade within the Euplotia. The genus Certesia forms a sister group to the Euplotes clade, also within the Euplotia assemblage.


Assuntos
Cilióforos/classificação , Cilióforos/citologia , Filogenia , Água do Mar/parasitologia , China , Cilióforos/genética , Águas Salinas , Especificidade da Espécie
19.
ISME J ; 14(2): 609-622, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31719654

RESUMO

Documenting the natural diversity of eukaryotic organisms in the nonhuman primate (NHP) gut is important for understanding the evolution of the mammalian gut microbiome, its role in digestion, health and disease, and the consequences of anthropogenic change on primate biology and conservation. Despite the ecological significance of gut-associated eukaryotes, little is known about the factors that influence their assembly and diversity in mammals. In this study, we used an 18S rRNA gene fragment metabarcoding approach to assess the eukaryotic assemblage of 62 individuals representing 16 NHP species. We find that cercopithecoids, and especially the cercopithecines, have substantially higher alpha diversity than other NHP groups. Gut-associated protists and nematodes are widespread among NHPs, consistent with their ancient association with NHP hosts. However, we do not find a consistent signal of phylosymbiosis or host-species specificity. Rather, gut eukaryotes are only weakly structured by primate phylogeny with minimal signal from diet, in contrast to previous reports of NHP gut bacteria. The results of this study indicate that gut-associated eukaryotes offer different information than gut-associated bacteria and add to our understanding of the structure of the gut microbiome.


Assuntos
Biodiversidade , Microbioma Gastrointestinal , Metagenômica , Primatas/microbiologia , Primatas/parasitologia , Animais , Animais Selvagens/microbiologia , Animais Selvagens/parasitologia , Blastocisto/classificação , Cercopithecidae/microbiologia , Cercopithecidae/parasitologia , Cilióforos/classificação , Cilióforos/genética , Cilióforos/isolamento & purificação , Dieta , Endolimax/classificação , Endolimax/genética , Endolimax/isolamento & purificação , Entamoeba/classificação , Entamoeba/genética , Eucariotos/classificação , Eucariotos/genética , Eucariotos/isolamento & purificação , Fezes/microbiologia , Fezes/parasitologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Hominidae/microbiologia , Hominidae/parasitologia , Especificidade de Hospedeiro , Lemur/microbiologia , Lemur/parasitologia , Nematoides/classificação , Nematoides/genética , Nematoides/isolamento & purificação , Filogenia , Platirrinos/microbiologia , Platirrinos/parasitologia
20.
Mol Phylogenet Evol ; 143: 106687, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31740334

RESUMO

Rumen ciliates are a specialized group of ciliates exclusively found in the anaerobic, carbohydrate-rich rumen microenvironment. However, the molecular and mechanistic basis of the physiological and behavioral adaptation of ciliates to the rumen microenvironment is undefined. We used single-cell transcriptome sequencing to explore the adaptive evolution of three rumen ciliates: two entodiniomorphids, Entodinium furca and Diplodinium dentatum; and one vestibuliferid, Isotricha intestinalis. We found that all three species are members of monophyletic orders within the class Litostomatea, with E. furca and D. dentatum in Entodiniomorphida and I. intestinalis in Vestibuliferida. The two entodiniomorphids might use H2-producing mitochondria and the vestibuliferid might use anaerobic mitochondria to survive under strictly anaerobic conditions. Moreover, carbohydrate-active enzyme (CAZyme) genes were identified in all three species, including cellulases, hemicellulases, and pectinases. The evidence that all three species have acquired prokaryote-derived genes by horizontal gene transfer (HGT) to digest plant biomass includes a significant enrichment of gene ontology categories such as cell wall macromolecule catabolic process and carbohydrate catabolic process and the identification of genes in common between CAZyme and HGT groups. These findings suggest that HGT might be an important mechanism in the adaptive evolution of ciliates to the rumen microenvironment.


Assuntos
Cilióforos/genética , Rúmen/parasitologia , Transcriptoma , Adaptação Fisiológica , Anaerobiose , Animais , Metabolismo dos Carboidratos , Celulases/genética , Cilióforos/classificação , Cilióforos/fisiologia , Transferência Genética Horizontal , Glicosídeo Hidrolases/genética , Filogenia , Poligalacturonase/genética , RNA-Seq , Rúmen/metabolismo , Análise de Célula Única
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