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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.
Phytochemistry ; 184: 112661, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33454615

RESUMO

Nine undescribed limonoids, 18(13 â†’ 14)-abeo-15ß,21-dihydroxy-24,25,26,27-tetranor-3,7-dioxoapotirucalla-1,9(11),13(17),20(22)-tetraen-23,21-olide (Toonaone A), 21-hydroxy-24,25,26,27-tetranor-3,7,15-trioxoapotirucalla-1,9(11),20(22)-trien-23,21-olide (Toonaone B), 7α,21-dihydroxy-12α-isobutyryl-24,25,26,27-tetranor-3,15-dioxoapotirucalla-1,20(22)-dien-23,21-olide (Toonaone C), 7,8-seco-7-methyl ester-11ß-acetoxy-14ß,15ß-epoxy-21-hydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,8(30),20(22)-trien-23,21-olide (Toonaone D), 7,8-seco-7-methyl ester-11ß-acetoxy-14ß,15ß-epoxy-23-hydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,8(30),20(22)-trien-21,23-olide (Toonaone E), 7,8-seco-7-methyl ester-11ß-acetoxy-14ß,15ß-epoxy-6ß,21-dihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,8(30),20(22)-trien-23,21-olide (Toonaone F), 7,8-seco-7-methyl ester-14ß,15ß-epoxy-8α,21-dihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,20(22)-dien-23,21-olide (Toonaone G), 7,8-seco-7-methyl ester-14ß,15ß-epoxy-6ß,8α,21-trihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,20(22)-dien-23,21-olide (Toonaone H), 7,8-seco-7-methyl ester-14ß,15ß-epoxy-6ß,8α,21-trihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,20(22)-dien-21,23-diimide (Toonaone I), and five known analogues were isolated from the twigs of Toona ciliata M. Roem. (Meliaceae). Toonaone A possesses the first rare 18(13 â†’ 14)-abeo-limonoid skeleton reported from the genus Toona. Their structures were elucidated using spectroscopic data analyses and quantum chemistry calculations. Biological evaluation showed that toonaone C, toonaone D, toonaone G, toonaciliatavarin F, and toonaciliatavarin G exhibited significant anti-NLRP3 inflammasome activity with IC50 values ranging from 3.74 to 18.7 µM. GMDMD, IL-1ß, and caspase-1 analyses suggested that toonaone D inhibited NLRP3 inflammasome activation and blocked macrophage pyroptosis.


Assuntos
Cilióforos , Limoninas , Inflamassomos , Limoninas/farmacologia , Estrutura Molecular , Proteína 3 que Contém Domínio de Pirina da Família NLR
6.
Eur J Protistol ; 78: 125694, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33500175

RESUMO

Denis Lynn (1947-2018) was an outstanding protistologist, applying multiple techniques and data sources and thus pioneering an integrative approach in order to investigate ciliate biology. For example, he recognized the importance of the ultrastructure for inferring ciliate phylogeny, based on which he developed his widely accepted classification scheme for the phylum Ciliophora. In this paper, recent findings regarding the evolution and systematics of both peritrichs and the mainly marine planktonic oligotrichean spirotrichs are discussed and compared with the concepts and hypotheses formulated by Denis Lynn. Additionally, the state of knowledge concerning the diversity of ciliates in bromeliad phytotelmata and amitosis in ciliates is reviewed.


Assuntos
Cilióforos , Biodiversidade , Cilióforos/classificação , Cilióforos/fisiologia , Classificação , Roma , Sociedades
7.
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
8.
Mar Pollut Bull ; 162: 111898, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33316704

RESUMO

The spatial distribution of microzooplankton in the northern South China Sea was investigated in March 2016. Microzooplankton communities were dominated by cyclotrichids, aloricate oligotrichs, and choreotrichs within ciliates and the order Gymnodiniales within dinoflagellates. Microzooplankton abundance varied between 60 and 166,520 cells L-1, with higher values in the coastal diluted water, and microzooplankton biomass exhibiting a similar pattern. High densities of Akashiwo cf. sanguinea were found in the upper waters along the coast, and mixotrophs dominated the communities in all the water masses. A canonical analysis of principal coordinates showed that the spatial patterns of microzooplankton communities could be clearly discriminated in the different water masses. Our findings provide insights into the functioning of microzooplankton and the potential risk of harmful Akashiwo cf. sanguinea algal blooms in coastal waters. In addition, our study provides evidence for using microzooplankton communities as potential indicators of water masses in complex marine systems.


Assuntos
Cilióforos , Dinoflagelados , China , Cadeia Alimentar , Proliferação Nociva de Algas
9.
Zootaxa ; 4894(3): zootaxa.4894.3.2, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33311069

RESUMO

Tintinnids are loricated ciliates found in coastal and oceanic waters that play a key role in the transference of energy to highest trophic levels. The purpose of this article is intended to integrate the available information about the taxonomy and distribution of Colombian tintinnids. An annotated distributional checklist based on published data is presented. One hundred and seven valid species of tintinnids, belonging to 12 families and 33 genera were listed. The genera Tintinnopsis and Eutinntinnus presented the highest number of species. Eighty-three species were recorded in the Caribbean basin and 51 in the Pacific, with a higher number in coastal waters.


Assuntos
Cilióforos , Animais , Colômbia
10.
Zootaxa ; 4890(3): zootaxa.4890.3.3, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33311117

RESUMO

Epibiosis is a common phenomenon, found in different taxa of aquatic animals. This relationship could occur as hyperepibiosis, when a basibiont being also an epibiont, providing a stable substrate for the hypersymbiont. Here we reported a ciliate-bryozoan-crustacean hyperepibiosis in Mandovi River mouth, Goa, West coast of India. We provided descriptions and characterization of the crab Atergatis sp., serving as basibiont for the bryozoan Triticella pedicellata (Alder, 1857), in turn colonized with (hyperepibionts) the ciliates Paracineta saifulae (Mereschkowsky, 1877) and Cothurnia ceramicola Kahl, 1933. Paracineta saifulae and Cothurnia ceramicola are reported here for first time from the Indian Ocean.


Assuntos
Braquiúros , Briozoários , Cilióforos , Animais , Índia
11.
Zootaxa ; 4895(1): zootaxa.4895.1.1, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33311051

RESUMO

Species from almost all classes of ciliates are prone to be found inhabiting bromeliads in the Neotropics, from Mexico to Brazil, and the Antilles. Studies of ciliates recorded from bromeliads have been carried out from few bromeliad species, mainly in tropical forest. We compiled all available data of free living and sessile ciliates from bromeliads, including their geographic distribution and bromeliad identity. We provide a list of 170 ciliate species that have been recorded in 52 epiphytic and terrestrial bromeliad species, distributed in ten Neotropical countries . Most of the species belong to the Classes Oligohymenophorea, Colpodea and Spirotrichea. The largest number of ciliate species has been recorded in Brazil and Mexico. Bromeliothrix metopoides and Glaucomides bromelicola were the two species with the widest geographical distribution, 19 species have been recorded only in Mexico, 11 in the Antillean islands, and 89 only in Southamerica. Free living species prevailed over sessile species, and both represent 2% of the total ciliate species number. Sixteen ciliate species have been recorded only inhabiting in bromeliads. Although bromeliads show a high endemicity, their specificity is low in relation to ciliates.


Assuntos
Alveolados , Bromeliaceae , Cilióforos , Animais
12.
Zootaxa ; 4859(3): zootaxa.4859.3.6, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33056191

RESUMO

Species concentration and composition of endosymbiotic ciliates were investigated in the forestomach contents of 12 dromedary camels (Camelus dromedarius) and the ruminal contents of 16 domestic cattle (Bos taurus taurus) living in Ben Gardane, Tunisia. Sixteen species and 8 morphotypes, belonging to 8 genera, were identified from dromedary camels, and 18 species and 13 morphotypes, belonging to 8 genera, were identified from domestic cattle. This is the first report on the endosymbiotic ciliated protozoan biota of dromedary camels and cattle living in Tunisia. The mean density (± SD) of ciliates in the forestomach samples of dromedary camels and the ruminal samples of domestic cattle was 65.4 ± 69.4 × 104 cells mL-1 and 54.2 ± 55.8 × 104 cells mL-1, respectively. Diplodinium cameli and Blepharoconus krugerensis were detected for the first and second time, respectively, from the ruminal contents of cattle. Caloscolex camelinus and B. krugerensis were studied in detail with a scanning electron microscope.


Assuntos
Camelus , Cilióforos , Animais , Biota , Bovinos , Rúmen , Tunísia
13.
Zootaxa ; 4821(1): zootaxa.4821.1.4, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33056332

RESUMO

The family Cycloposthiidae include 69 species, distributed in 17 genera, all of them described in symbiotic association with various mammalian host species. The taxonomic classification of the family is confused because of its broad diagnosis and absence of synapomorphies. To validate taxa and eliminate synonyms, the present work performed a brief taxonomic review of Cycloposthiidae, compiling morphological characterization, host records, and geographic location data. According to our review, the family should be instead, composed of 13 genera and 66 species; it was observed that the currently in use taxonomic characters do not reflect evolutionary divergence; and that the broad host range of Cycloposthiidae may be linked to cortex characteristics of these organisms or because of the fact that they do not constitute a monophyletic group. Thus, the performance of more molecular phylogenetic studies, including more cycloposthiid representatives and as well as the use of recent morphological techniques would be necessary to clarify the taxonomy of the group.


Assuntos
Cilióforos , Animais , Evolução Biológica , Especificidade de Hospedeiro , Filogenia
14.
Zootaxa ; 4763(1): zootaxa.4763.1.2, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33056876

RESUMO

A compilation of the ciliated species found on freshwater and marine ostracods as epibiont or parasite (endobiont) has been carried out based on published records. The checklist includes the taxonomic position of each species of epibiontic and endobiontic ciliate, the species of basibiont ostracodes, the geographic zones and the bibliographic references where they were recorded. Altogether 7 suctorian, 29 peritrich, one apostome and one scuticociliatid species were listed. Two of recorded suctorian species are possible specific to marine ostracodes, whereas only one, Tokophrya sibirica to freshwater hosts. Fourteen species of peritrichs are likely specific to freshwater ostracodes, while three possible specific to marine ostracode hosts. Other suctorian and peritrich ciliate species were found on a variety of host taxa. One species of scuticociliatid was recorded as endobiont in ostracod.


Assuntos
Cilióforos , Animais , Crustáceos , Água Doce , Registros
15.
Water Sci Technol ; 82(1): 67-80, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32910793

RESUMO

The work is devoted to the task of simplifying the assessment of the effect of effluents from treatment facilities on the river hydrobiocenosis. The studies were carried out on the mountain river Uzh (Uzhgorod, Ukraine). Our approach to assessing the impact of waste treatment facilities on the river receiver is based on the estimate of the similarity of species composition and quantitative characteristics of populations of organisms from the aerotank and from the river. It is shown that the quantitative development of populations of species of ciliates from the aeration tank is a good indicator for assessing the degradation of organic matter coming with wastewater. The use of qualitative and quantitative characteristics of the protozoa from the wastewater treatment plant as a criterion for assessing the quality of the environment in the area of wastewater discharge showed their representativeness and effectiveness. The use of a limited number of species makes it possible to conduct an express assessment of the effect of effluents on receiving reservoirs for specialists working with activated sludge in the laboratories of treatment facilities.


Assuntos
Cilióforos , Águas Residuárias , Ecossistema , Veículos Automotores , Rios
16.
Sci Total Environ ; 743: 140665, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32927525

RESUMO

This study screened six different species of forest plants and then further evaluated the most promising plant, giant milkweed (Calotropis gigantea), for the potential to improve nitrogen utilization efficiency (NUE) through inhibiting rumen protozoa in vitro. Ground leaves of giant milkweed at 1.6 and 3.2 mg/mL decreased the counts of Entodinium cells by 41.30% and 58.89%, respectively, and damaged their cell surface structure. Dasytricha, Isotricha, Epidinium, Ophryoscolex, and Diplodinium were not affected, while total bacterial and archaeal populations did not decrease. Ammonia nitrogen (NH3-N) concentration decreased by 50.64% and 33.33% at 1.6 g/mL and 3.2 mg/mL, respectively. Volatile fatty acid (VFA) production and methane production remained unaffected, but butyrate production increased. The giant milkweed leaves contained (per gram of dry matter) 3636 µg phenolics including 205.9 µg of 3-hydroxybenzoic acid, 2079 µg flavonoids including 1197.5 µg of quercetin and 91.4 µg of myricetin, and 490 µg alkaloids including 219.8 µg of anthraquinone glycosides. The effective inhibition of Entodinium was accompanied by a decrease in NH3-N concentration, and methane production did not increase except for the dose of 1.6 mg/mL. Giant milkweed may be used as a new feed additive or an alternative to chemicals or antibiotics for sustainable animal husbandry enhancing NUE in ruminants.


Assuntos
Calotropis , Cilióforos , Microbiota , Ração Animal , Animais , Dieta , Fermentação , Metano , Rúmen
17.
Mar Pollut Bull ; 160: 111604, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32871431

RESUMO

Biological trait analysis (BTA) has been proved to be a powerful tool to evaluate marine water quality. The species trait distributions of biofilm-dwelling protozoa were studied in a coastal region of the Yellow Sea, northern China, during a four-season cycle. The BTA demonstrated that: (1) the protozoa showed a significant seasonal variability in biological trait pattern during the colonization process across four seasons; (2) the colonization dynamics in species trait distribution followed different temporal models; (3) the functional dynamics in spring and summer were significantly different from those in autumn and winter (P < 0.05); and (4) functional diversity showed lower values in spring and summer than in autumn and winter. These findings suggest that BTA is subject to a high seasonal variability during colonization surveys when protozoa are used as bioindicators of marine water quality.


Assuntos
Cilióforos , Biofilmes , China , Monitoramento Ambiental , Estações do Ano , Inquéritos e Questionários
18.
Mar Pollut Bull ; 159: 111444, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32778527

RESUMO

To identify the seasonal variability of body-size spectrum for monitoring surveys based on periphytic protozoa, a one-year baseline survey was carried out in a coastal region of Yellow Sea, northern China. A total of 240 glass slides were collected after immersion times of 3, 7, 10, 14, 21 and 28 days in a four season cycle, i.e., winter, spring, summer, and autumn. Body-size ranks S2 and S5 dominated the periphytic protozoan communities from the initial stage (from day 3) to the next periods in spring and autumn, while body-size ranks S7, S8 and S4 showed high variety at the equilibrium stages (from day 10) in summer and winter. The expectation analysis revealed that the samples had different patterns of departure from the anticipated body-size spectrum in each season. This study shows that an ideal sampling approach needs to be established when protozoa is used as bioindicators of marine water quality.


Assuntos
Cilióforos , Biodiversidade , China , Ecossistema , Monitoramento Ambiental , Estações do Ano
19.
Ecotoxicol Environ Saf ; 202: 110937, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800220

RESUMO

Cyanobacteria have been considered a major global threat because of their widespread ability to proliferate and contaminate inland and marine waters with toxic metabolites. For this reason, to avoid risks to humans and environmental health, regulatory legislation and guidelines have been established based on extensive toxicological data. However, most of what is known in this field come from works on microcystin (MC) variants, which effects were almost exclusively tested in metazoan models. In this work, we used acute end-point toxicological assays and high-resolution hybrid quadrupole time-of-flight mass spectrometer coupled with electrospray ionization source (ESI-Q-TOF-MS) analyses to evaluate the deleterious impact of aqueous extracts prepared from cultures of cyanobacteria and environmental bloom biomasses over a non-metazoan model organism, the cosmopolitan fresh/brackish water unicellular microeukaryote, Paramecium caudatum (Ciliophora). Our data suggest that all extracts produced time-dependent effects on P. caudatum survival, irrespective of their metabolite profile; and that this ciliate is more sensitive to extracts containing microginins than to extracts with only MCs, stressing that more toxicological investigations should be performed on the environmental impact of neglected cyanotoxins. Further, our data provide evidence that P. caudatum may be more sensitive to cyanotoxins than vertebrates, indicating that guidelines values, set on metazoans are likely to be inaccurate to protect organisms from basal food web positions. Thus, we highly recommend the widespread use of microeukaryotes, such as ciliates in environmental risk assessment frameworks for the establishment of more reliable cyanotoxin monitoring guideline values.


Assuntos
Cianobactérias/crescimento & desenvolvimento , Paramecium caudatum/fisiologia , Animais , Biomassa , Cilióforos , Cadeia Alimentar , Água Doce/microbiologia , Humanos , Microcistinas
20.
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
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