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1.
Eur J Protistol ; 78: 125767, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33639326

RESUMO

The peritrich genus Epistylis is speciose, however many species lack complete morphological description based on modern criteria and/or molecular data. In the present study, one new species, i.e., E. foissneri n. sp., and two morphologically similar species, i.e., E. hentscheli Kahl, 1935 and E. vaginula Stokes, 1884, collected from freshwater habitats in China, were studied. Epistylis foissneri n. sp. is characterized by its extremely slender zooids encased in a gelatinous sheath, symmetrically dichotomously branched stalk, trochal band located at mid-body, contractile vacuole located on dorsal wall of infundibulum, infundibular polykinety 3 (P3) composed of three equal-length rows that terminate above infundibular polykinety 1 (P1), 105-110 silverlines between the peristome and the trochal band, and about 110 silverlines between the trochal band and the scopula. Epistylis hentscheli is characterized by its asymmetric pyriform zooids (average length ca. 160 µm in vivo), dichotomously branched stalk with transverse striations on the surface of the upper portion, P3 three-rowed and terminating slightly above P1, 60-75 silverlines between the peristome and the trochal band, and 55-90 silverlines between the trochal band and the scopula. Epistylis vaginula is characterized by its elongated body shape (about 100 µm in length in vivo), dichotomously branched and smooth stalk, P3 three-rowed and terminating above P1, 80-100 silverlines between the peristome and the trochal band, and 45-80 silverlines between the trochal band and the scopula. The small subunit ribosomal DNA gene (SSU rDNA) of these three species was sequenced and supported the validity of each. Phylogenetic analyses based on SSU rDNA sequence data revealed that all three morphospecies group with other congeners within the major clade of Epistylis.


Assuntos
Água Doce , Oligoimenóforos/classificação , Filogenia , China , DNA de Protozoário/genética , Água Doce/parasitologia , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
2.
Mol Phylogenet Evol ; 154: 107003, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33137410

RESUMO

Peniculids comprise a large order of ciliated protists in Class Oligohymenophorea having many unresolved evolutionary relationships. Herein, we report 27 new sequences, including 18S rRNA, ITS1-5.8S- ITS2 rRNA, 28S rRNA and the mitochondrial cox1 genes of eight peniculids. We conducted phylogenetic analyses based on each these markers and on a four-gene concatenated data set (18S rRNA, ITS1-5.8S- ITS2 rRNA, 28S rRNA, and cox1 gene). The main findings are: 1) subclass Peniculia and family Parameciidae are monophyletic, with genus Frontonia remaining non-monophyletic; 2) Urocentrids have traditionally been regarded as a family, multi-gene analyses support the rank of Urocentrida and consistently recovers this order as sister to Peniculida, and Urocentrida and Peniculida comprise subclass Peniculia in agreement with Lynn's (2008) classification; 3) discrepancies between multiple-gene phylogenies, and conflicts with morphologic data regarding genus Frontonia necessitate expansion and revision of species diagnoses and we propose consideration of Group III of Frontonia (including F. didieri, F. ocularis, F. anatolica, F. pusilla and F. elegans) as incertae sedis in Peniculida; 4) multi-gene analyses of Parameciidae support five previously established subgenera. Paramecium buetschlii is placed in subgenus Chloroparamecium, and P. chlorelligerum into subgenus Viridoparamecium.


Assuntos
Oligoimenóforos/classificação , Oligoimenóforos/genética , Filogenia , Teorema de Bayes , DNA Intergênico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes Mitocondriais , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
3.
Protist ; 171(4): 125751, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32890795

RESUMO

With highly specialized morphology and unexplored functional capacities, ciliates from extreme habitats are drawing increasing attention. During a microbial investigation of a solar saltern pond (salinity 240‰) on Mallorca, Spain, a previously unknown scuticociliate, Platynematum rossellomorai n. sp. was isolated, cultured and studied using a tripartite approach consisting of a morphological description, a molecular analysis and an ecophysiological characterization. The ciliate has distinct morphological characteristics and its main diagnostic features include a large anteriorly positioned oral area (occupying almost half of the body length), two caudal cilia and a small number of somatic kineties. However, due to the most important generic feature of Cinetochilidae, the consistency of the arrangement of the adoral membranes, the ciliate is classified as a new member of the genus Platynematum. Its 18S rRNA gene sequence shows a sequence similarity of 91.0% to the closest deposited relative, Platynematum salinarum, and a phylogenetic analysis reveals a close relationship to other members of the family Cinetochilidae Perty, 1852. Growth experiments identify the ciliate as a borderline halophile, with a tolerance range between 180 and 280‰ salinity. The ciliate apparently accumulates the compatible solutes glycine betaine and ectoine to counterbalance osmotic stress, however, other osmoregulatory mechanisms are not excluded.


Assuntos
Oligoimenóforos/classificação , Filogenia , Tanques/parasitologia , DNA de Protozoário/genética , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Espanha , Especificidade da Espécie
4.
Parasitol Res ; 119(8): 2597-2608, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32607707

RESUMO

Trichodinid ciliates were isolated from calanoid copepods and were characterized by morphological and molecular techniques. The trichodinids found in this study were morphologically similar to Trichodina acuta, but morphometric differences were observed between our specimens and T. acuta. The T. acuta specimens, isolated from fish in several geographical locations around the world, were slightly larger than specimens in our population. In fact, our morphological and morphometric data are more similar to Trichodina diaptomi populations, also found on copepods. Moreover, our phylogenetic analyses revealed that the 18S rRNA gene sequence from our samples emerged in a clade with two T. acuta sequences, infesting fish hosts in China. These three sequences showed 100% identity. Our data, along with a taxonomic review, suggest that the species T. diaptomi, described recently, is actually a synonym of T. acuta and that this species may be related to fish and copepod hosts. In conclusion, we highlight the urgent need to better investigate the polymorphism and host specificity within the Mobilida, as this data may represent important characters to better understand the evolution into this order.


Assuntos
Copépodes/parasitologia , Oligoimenóforos/classificação , Animais , DNA de Protozoário/genética , Peixes/parasitologia , Especificidade de Hospedeiro , Oligoimenóforos/citologia , Oligoimenóforos/genética , Filogenia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
5.
Int J Syst Evol Microbiol ; 70(4): 2405-2419, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32559827

RESUMO

The morphology of two new scuticociliates, Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., isolated from a mangrove wetland in Shenzhen, PR China, was studied using live observation and the protargol impregnation method. Uronema apomarinum is characterized by a body size of about 20-35×10-15 µm in vivo, a partly two-rowed membranelle 1, and 12 or 13 somatic kineties. Homalogastra parasetosa is distinguished by a membranelle 1 comprising two longitudinal rows of basal bodies. Three Homalogastra setosa populations are suggested as subjective synonyms of the new species. Improved diagnoses of the genus Homalogastra Kahl, 1926 and its type species Homalogastra setosa Kahl, 1926 are provided. Results of phylogenetic analyses based on 18S rRNA gene and ITS1-5.8S-ITS2 region sequences indicate that U. apomarinum is most closely related to U. marinum, while the closest relative of H. parasetosa is H. setosa.


Assuntos
Oligoimenóforos/classificação , Filogenia , China , DNA Espaçador Ribossômico/genética , Oligoimenóforos/isolamento & purificação , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Proteínas de Prata , Áreas Alagadas
6.
Eur J Protistol ; 74: 125644, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32460119

RESUMO

Three freshwater scuticociliates, Apouronema harbinensis gen. nov. spec. nov., Cyclidium vorax spec. nov., and C. glaucomaMüller, 1773, collected from rivers in Hulan District, Harbin, northeastern China, were investigated using morphological and phylogenetic criteria. Apouronema gen. nov., assigned to the family Uronematidae, is mainly distinguished from the other genera of the family by its paroral membrane extending anteriorly to the middle of membranelle 1. Apouronema harbinensis spec. nov. is defined by body size in vivo about 45-55 × 20-25 µm, buccal field about 70-80% of cell length; 12 or 13 somatic kineties; membranelle 1 having two rows, with 16-18 basal bodies in each kinety; membranelle 2 and membranelle 3 both having two rows each; scutica X-shaped with five pairs of basal bodies. Cyclidium vorax spec. nov. is characterized by the following features: body size 35-40 × 18-20 µm in vivo; 9 or 10 somatic kineties; membranelle 1 having two longitudinal rows, much shorter than M2; M2 triangle-shaped. The phylogenetic analyses show that: (1) Apouronema clustered in the Uronematidae clade, and grouped with genera Uronemita and Uronema; (2) Cyclidium vorax spec. nov. grouped with C. glaucoma and C. sinicum, which supports the assignment of the new species to the genus Cyclidium; (3) Cyclidium remains non-monophyletic with the addition of the new sequence.


Assuntos
Oligoimenóforos/classificação , Oligoimenóforos/genética , China , DNA de Protozoário/genética , Água Doce , Oligoimenóforos/citologia , Filogenia , Especificidade da Espécie
7.
Eur J Protistol ; 73: 125673, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32007803

RESUMO

The parasitic ciliate causing shrimp black gill (sBG) infections in penaeid shrimp has been identified. The sBG ciliate has a unique life cycle that includes an encysted divisional stage on the host's gills. The ciliature of the encysted trophont stage has been determined and is quite similar to that of the closely related apostomes Hyalophysa bradburyae and H. chattoni. Hyalophysa bradburyae is a commensal ciliate associated with freshwater caridean shrimp and crayfish, while H. chattoni is a common commensal found on North American marine decapods. Based on 18S rRNA gene sequence comparisons, the sBG ciliate is more closely related to the marine species H. chattoni than to the freshwater species H. bradburyae. The unique life cycle, morphology, 18S rRNA gene sequence, hosts, location, and pathology of the sBG ciliate distinguish this organism as a new species, Hyalophysa lynni n. sp.


Assuntos
Oligoimenóforos/classificação , Penaeidae/parasitologia , Animais , Brânquias/parasitologia , Especificidade de Hospedeiro , Estágios do Ciclo de Vida , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
8.
Eur J Protistol ; 73: 125670, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31968298

RESUMO

Four epibiotic sessilid peritrichs, i.e., Zoothamnium wilberti n. sp., Baikalonis microdiscus n. sp., Epistylis anastatica (Linnaeus, 1767) Ehrenberg, 1830, and Rhabdostyla commensalisMöbius, 1888, were isolated from one syllid polychaete and three crustacean hosts in Qingdao, China. For each species, specimens were observed both in vivo and following silver staining. Their SSU rDNA was also sequenced for phylogenetic analyses. Zoothamnium wilberti n. sp. is characterized by the appearance of its colony, which is up to 350 µm high, and usually has fewer than 16 zooids, and the dichotomously branched stalk with transverse wrinkles, the conspicuously conical peristomial disc, and infundibular polykinety 3 comprising three isometric ciliary rows. Baikalonis microdiscus n. sp. can be recognized by its barrel-shaped zooid, small peristomial disc, smooth and short stalk, and its unusual infundibular polykinety 3 comprising a long inner row and a short outer row. Two poorly known species, i.e., Epistylis anastatica and Rhabdostyla commensalis, are redescribed and redefined. Phylogenetic analyses reveal that: (i) R. commensalis is closely related to the family Astylozoidae rather than to the morphologically similar Epistylididae; (ii) B. microdiscus n. sp. is sister to the family Scyphidiidae; (iii) E. anastatica groups with vorticellids and ophrydiids, which further supports the polyphyly of the genus Epistylis; and (iv) Z. wilberti n. sp. is nested within the Zoothamniidae, as expected.


Assuntos
Crustáceos/parasitologia , Oligoimenóforos/classificação , Poliquetos/parasitologia , Animais , China , DNA de Protozoário/genética , Oligoimenóforos/citologia , Oligoimenóforos/genética , Filogenia , Especificidade da Espécie
9.
Eur J Protistol ; 72: 125647, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31877437

RESUMO

In the present study, we provide morphological and molecular characterization of two Trichodina species, T. acuta Lom, 1970 and T. funduliWellborn, 1967, isolated from koi (Cyprinus carpio) and loach (Paramisgurnus dabryanus), respectively. Morphological characters of the two Trichodina species were mainly investigated on the basis of dry silver nitrate-impregnated specimens. Both species are medium-sized and possess well-developed denticles comprising strongly sickle-shaped blades, well-developed central parts, and straight rays. Trichodina acuta can be easily distinguished from the other Trichodina species that possess a clear central circle by the well-developed sharp blade apophysis, and the gap between ray tip and central circle. Trichodina funduli is a poorly known species that is easily confused with T. heterodentata Duncan, 1977, however the latter species has thinner denticles. The small subunit ribosomal RNA gene sequences of Trichodina acuta and T. funduli were incorporated into phylogenetic analyses. Our findings suggest that the phylogenetic lineage of trichodinids might not correspond with their living environments, host species or even some morphological characteristics.


Assuntos
Peixes/parasitologia , Oligoimenóforos/classificação , Filogenia , Animais , China , Água Doce , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
10.
Eur J Protistol ; 71: 125635, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31553939

RESUMO

The morphology, infraciliature, and silverline system of two peritrich ciliates, Pseudovorticella littoralis sp. n. and P. alani sp. n., isolated from coastal waters of southern China, were investigated based on both living and silver-stained specimens. Pseudovorticella littoralis sp. n. is characterized by the following combination of characters: cell inverted cone-shaped; contractile vacuole ventral; J-shaped macronucleus; infundibular polykinety 3 with two kinetosome rows of equal length; 19-26 silverlines from peristome to trochal band and 5-14 from trochal band to scopula. Pseudovorticella alani sp. n. is characterized by: cell inverted bell-shaped; contractile vacuole ventral; J-shaped macronucleus recurved almost forming a loop; infundibular polykinety 3 with three kinetosome rows, outer two rows longer than inner one; 48-61 silverlines between peristome and aboral trochal band, and 12-20 between aboral trochal band and scopula. The SSU rDNA sequences of both new species are reported and their genetic distances with congeners and phylogenetic relationships are investigated. Pseudovorticella and Epicarchesium cluster into two subclades with low support values. One subclade contains nearly all the available sequences of Pseudovorticella and Epicarchesium. Another one contains P. monilata and E. pectinatum. This calls on the need of a generic re-classification of Pseudovorticella and Epicarchesium based on more morphological and molecular data.


Assuntos
Oligoimenóforos/classificação , Filogenia , Água do Mar/parasitologia , China , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
11.
Parasite ; 26: 47, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31359860

RESUMO

Trichodinids, which are ciliate protists, are causative agents of an aquatic animal disease, trichodiniasis, especially among both captive and wild fish. This disease can adversely affect aquaculture and have economic impacts. The objectives of this study were to evaluate the prevalence and mean intensity of Trichodina unionis infection, describe qualitative and quantitative morphological characters, and perform a molecular phylogenetic analysis. The gastropod samples were randomly collected by hand-picking and a hand net. Trichodina unionis was collected by the crushing method under a stereomicroscope. Among all 4977 examined gastropods, 55 individuals of two gastropod species, Gyraulus siamensis and Physella acuta, were found to be infected by T. unionis, with overall prevalence and mean intensity of infection of 1.11% and 16.65, respectively. The characteristics of the denticles indicated T. unionis as having moderately wide blades and moderately curved blade margins, with distinctive bend angles near the distal end. The quantitative characters showed some variations, which could be due to food availability. Molecular phylogenetic analysis conducted with 18S rRNA provided a monophyletic tree of our specimens and previously identified T. unionis, confirming species identification. This study represents the first record of T. unionis in Thailand.


Assuntos
Infecções por Cilióforos/parasitologia , Gastrópodes/parasitologia , Oligoimenóforos/classificação , Oligoimenóforos/isolamento & purificação , Filogenia , Animais , Água Doce/parasitologia , Especificidade da Espécie , Tailândia
12.
Rev Bras Parasitol Vet ; 28(2): 229-237, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271640

RESUMO

Massive occurrence of trichodinids is frequently accompanied by serious disease in fish farms. In this study, trichodinid species from the gills and skin of Nile tilapia (Oreochromis niloticus) farmed in the central-western region of Brazil (state of Goiás) were morphologically characterized. Dried slides were prepared from the parasites and were impregnated with silver nitrate (2%). Morphometric characteristics were determined and schematic drawings of the denticles were made using photomicrographs produced from the slides. Seven species of trichodinid ectoparasites (Protozoa: Ciliophora: Trichodinidae) were found parasitizing the gills: four of the genus Trichodina Ehrenberg, 1838; one of Tripartiella Lom, 1959; one of Paratrichodina Lom, 1963; and one of Trichodinella Srámek-Husek, 1953. On the body surface, three specimens of the genus Trichodina were identified. This study presents new geographical records of trichodinids in Brazil, thus confirming that Trichodina centrostrigeata, Trichodina compacta, Trichodina heterodentata, Paratrichodina africana and Tripartiella orthodens are widely distributed worldwide. Additionally, the first record of the genus Trichodinella in Brazil is presented.


Assuntos
Ciclídeos/parasitologia , Infecções por Cilióforos/veterinária , Cilióforos/isolamento & purificação , Doenças dos Peixes/parasitologia , Oligoimenóforos/isolamento & purificação , Animais , Aquicultura , Brasil , Cilióforos/classificação , Infecções por Cilióforos/parasitologia , Pesqueiros , Oligoimenóforos/classificação
13.
Mol Phylogenet Evol ; 139: 106565, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31326515

RESUMO

So far, the phylogenetic studies on ciliated protists have mainly based on single locus, the nuclear ribosomal DNA (rDNA). In order to avoid the limitations of single gene/genome trees and to add more data to systematic analyses, information from mitochondrial DNA sequence has been increasingly used in different lineages of ciliates. The systematic relationships in the subclass Scuticociliatia are extremely confused and largely unresolved based on nuclear genes. In the present study, we have characterized 72 new sequences, including 40 mitochondrial cytochrome oxidase c subunit I (COI) sequences, 29 mitochondrial small subunit ribosomal DNA (mtSSU-rDNA) sequences and three nuclear small subunit ribosomal DNA (nSSU-rDNA) sequences from 47 isolates of 44 morphospecies. Phylogenetic analyses based on single gene as well as concatenated data were performed and revealed: (1) compared to mtSSU-rDNA, COI gene reveals more consistent relationships with those of nSSU-rDNA; (2) the secondary structures of mtSSU-rRNA V4 region are predicted and compared in scuticociliates, which can contribute to discrimination of closely related species; (3) neither nuclear nor mitochondrial data support the monophyly of the order Loxocephalida, which may represent some divergent and intermediate lineages between the subclass Scuticociliatia and Hymenostomatia; (4) the assignments of thigmotrichids to the order Pleuronematida and the confused taxon Sulcigera comosa to the genus Histiobalantium are confirmed by mitochondrial genes; (5) both nuclear and mitochondrial data reveal that the species in the family Peniculistomatidae always group in the genus Pleuronema, suggesting that peniculistomatids are more likely evolved from Pleuronema-like ancestors; (6) mitochondrial genes support the monophyly of the order Philasterida, but the relationships among families of the order Philasterida remain controversial due to the discrepancies between their morphological and molecular data.


Assuntos
Núcleo Celular/genética , Mitocôndrias/genética , Oligoimenóforos/classificação , DNA Ribossômico/química , DNA Ribossômico/classificação , DNA Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Conformação de Ácido Nucleico , Oligoimenóforos/genética , Filogenia , RNA Ribossômico/química , RNA Ribossômico/classificação , RNA Ribossômico/genética , Análise de Sequência de DNA
14.
J Eukaryot Microbiol ; 66(6): 869-881, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30977159

RESUMO

The biodiversity of peritrich ciliates from brackish biotopes is rarely investigated, especially members of the genus Pseudovorticella. Here, the morphology of three species of Pseudovorticella, i.e. P. cf. vestita (Stokes, 1883) Jankowski, 1976, P. spathulata sp. n., and P. qinghaiensis sp. n. isolated from brackish waters were studied. Pseudovorticella cf. vestita is characterized by inverted bell-shaped cell; a J-shaped macronucleus; a single contractile vacuole ventrally located; P3 three-rowed; pellicle striated with highly developed pellicular vesicles; 18-22 transverse silverlines between peristome and aboral trochal band, and 9-13 between aboral trochal band and scopula. Pseudovorticella spathulata sp. n. differs from its congeners by the following combination of characters: elongate-elliptical cell; a single contractile vacuole near ventral wall of infundibulum; a J-shaped macronucleus; P3 three-rowed; 24-34 silverlines between oral area and aboral trochal band and 6-10 between aboral trochal band and scopula. Pseudovorticella qinghaiensis sp. n. is characterized by: cell with an oval outline; a single contractile vacuole near ventral wall of infundibulum; a C-shaped macronucleus; P3 three-rowed; 30-35 and 9-11 transverse silverlines above and below the trochal band, respectively. The SSU rDNA sequences of five Pseudovorticella species, namely P. annulata, P. monilata, P. parakenti, P. spathulata sp. n., and P. cf. vestita, plus that of Zoothamnium hartwigi, are reported for the first time and their evolutionary relationships are investigated. Five undefined Pseudovorticella forms are considered might be conspecific with P. monilata. Two congeners are conspecific with P. spathulata sp. n. Phylogenetic analyses based on SSU rDNA sequences reveal that Pseudovorticella is not monophyletic and Z. hartwigi clusters with its congeners as expected.


Assuntos
Lagos/parasitologia , Oligoimenóforos/classificação , Água do Mar/parasitologia , China , Oligoimenóforos/citologia , Oligoimenóforos/genética , Filogenia , RNA de Protozoário/análise , Águas Salinas , Áreas Alagadas
15.
Rev. bras. parasitol. vet ; 28(2): 229-237, Apr.-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1013746

RESUMO

Abstract Massive occurrence of trichodinids is frequently accompanied by serious disease in fish farms. In this study, trichodinid species from the gills and skin of Nile tilapia (Oreochromis niloticus) farmed in the central-western region of Brazil (state of Goiás) were morphologically characterized. Dried slides were prepared from the parasites and were impregnated with silver nitrate (2%). Morphometric characteristics were determined and schematic drawings of the denticles were made using photomicrographs produced from the slides. Seven species of trichodinid ectoparasites (Protozoa: Ciliophora: Trichodinidae) were found parasitizing the gills: four of the genus Trichodina Ehrenberg, 1838; one of Tripartiella Lom, 1959; one of Paratrichodina Lom, 1963; and one of Trichodinella Ṧrámek-Huṧek, 1953. On the body surface, three specimens of the genus Trichodina were identified. This study presents new geographical records of trichodinids in Brazil, thus confirming that Trichodina centrostrigeata, Trichodina compacta, Trichodina heterodentata, Paratrichodina africana and Tripartiella orthodens are widely distributed worldwide. Additionally, the first record of the genus Trichodinella in Brazil is presented.


Resumo O parasitismo intenso por tricodinídeos está frequentemente relacionado à doença grave em fazendas de peixes. Neste estudo, espécies de tricodinídeos das brânquias e da pele de tilápias do Nilo (Oreochromis niloticus) cultivadas na região centro-oeste do Brasil (estado de Goiás) foram caracterizadas morfologicamente. As lâminas secas foram preparadas a partir dos parasitas e impregnadas com nitrato de prata (2%). As características morfométricas foram determinadas e desenhos esquemáticos dos dentículos foram confeccionados com fotomicrografias produzidas a partir das lâminas. Sete espécies de ectoparasitos tricodinídeos (Protozoa: Ciliophora: Trichodinidae) foram encontradas parasitando as brânquias: quatro do gênero Trichodina Ehrenberg, 1838; um de Tripartiella Lom, 1959; um de Paratrichodina Lom, 1963; e um de Trichodinella Ṧrámek-Huṧek, 1953. Na superfície do corpo, três espécimes do gênero Trichodina foram identificados. Este estudo apresenta novos registros geográficos de tricodinídeos no Brasil, confirmando que Trichodina centrostrigeata, Trichodina compacta, Trichodina heterodentata, Paratrichodina africana e Tripartiella orthodens estão amplamente distribuídas mundialmente. Adicionalmente, é apresentado o primeiro registro do gênero Trichodinella no Brasil.


Assuntos
Animais , Oligoimenóforos/isolamento & purificação , Infecções por Cilióforos/veterinária , Cilióforos/isolamento & purificação , Ciclídeos/parasitologia , Doenças dos Peixes/parasitologia , Brasil , Oligoimenóforos/classificação , Infecções por Cilióforos/parasitologia , Cilióforos/classificação , Aquicultura , Pesqueiros
16.
J Invertebr Pathol ; 161: 40-46, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30684497

RESUMO

Black spot gill syndrome in the northern shrimp, Pandalus borealis, is caused by an apostome ciliate, Synophrya sp., found within the gill lamellae. Whole mount staining, thin section histology, electron microscopy, and molecular studies were carried out on infected gills. The Synophrya 18S rRNA from Pandalus borealis (Genbank accession no. KX906568) and from two portunid crab species, Achelous spinimanus (Genbank accession no. MH395150) and Achelous gibbesii (Genbank accession no. MH395151) was sequenced. Phylogenetic analyses confirmed the identity of these ciliates as apostomes. The 18S rRNA sequence recovered from P. borealis shared 95% nucleotide similarity with the sequences recovered from the portunid crab species suggesting that it is a different species of Synophrya. The invasive hypertrophont stages, with a distinctive macronuclear reticulum, ranged in size from 300 to 400 µm with as many as 5 large forms/mm2 of gill tissue. Histotrophic hypertrophont stages and hypertomont stages were observed in these studies. The presence of the parasite was linked to the formation of melanized nodules (up to 9 nodules/mm2 of gill tissue) by the host and in some cases to extensive necrosis. Other studies have reported Synophrya sp. infections in P. borealis from Greenland, Labrador and Newfoundland, but further studies are necessary to determine the prevalence of this parasite in the dense schools of northern shrimp in the North Atlantic. Questions remain as to the possibility of epizootics of this pathogen and its impact on northern shrimp populations.


Assuntos
Infecções por Cilióforos/parasitologia , Brânquias/patologia , Oligoimenóforos , Pandalidae/parasitologia , Animais , Aquicultura , Braquiúros/parasitologia , Brânquias/parasitologia , Oligoimenóforos/classificação , Oligoimenóforos/genética , Oligoimenóforos/crescimento & desenvolvimento , Filogenia , RNA Ribossômico 18S , Alimentos Marinhos
17.
J Eukaryot Microbiol ; 66(4): 670-679, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30629314

RESUMO

A new peritrichous ciliate, Zoothamnium palmphlatum nov. spec., was collected from an estuary in Yantai, China. It was investigated, using both live observation and silver staining. The new species can be identified by a palm-shaped colony consisting of highly developed and alternately arranged secondary branches, a double-layered peristomial lip, and an infundibular polykinety 3 composed of two parallel kinetosomal rows. Phylogenetic analyses of the small subunit (SSU) rRNA gene sequence show that Z. palmphlatum clusters with other members of the family Zoothamniidae. Furthermore, the comparison of primary and secondary SSU rDNA structures indicates that Z. palmphlatum is distinctly different from its morphologically similar species (93.2-97.0% in sequence similarity) in combination of H10 and H31 regions. Although Z. palmphlatum shares highest sequence similarity with Zoothamnium mucedo (98.9%), the new species has distinctly different structures in the H11, H12, H18, and H31 regions compared to Z. mucedo, which indicates that sequence similarity may not determine the similarity of the secondary structure.


Assuntos
Oligoimenóforos/classificação , Filogenia , Sequência de Bases , China , DNA de Protozoário/genética , DNA Ribossômico/genética , Estuários , Oligoimenóforos/citologia , Oligoimenóforos/genética , Alinhamento de Sequência
18.
J Eukaryot Microbiol ; 66(2): 267-280, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30025176

RESUMO

Four new species of Vorticella, V. parachiangi sp. n., V. scapiformis sp. n., V. sphaeroidalis sp. n., and V. paralima sp. n., were isolated from coastal brackish waters of southern China. Their morphology, infraciliature, and silverline system were investigated based on observations of specimens both in vivo and following silver staining. Vorticella parachiangi sp. n. is distinguished by: a J-shaped macronucleus; a single dorsally located contractile vacuole; a two-rowed infundibular polykinetid 3, in which row 1 is shorter than row 2; 21-31 silverlines between peristome and aboral trochal band, 6-11 between aboral trochal band and scopula. Vorticella scapiformis sp. n. is characterized by its conspicuously thin and irregularly edged peristomial lip; a J-shaped macronucleus; a single, ventrally located contractile vacuole; row 1 of the infundibular polykinetid 3 proximally shortened; 18-25 silverlines between peristome and aboral trochal band, 8-12 between aboral trochal band and scopula. Vorticella sphaeroidalis sp. n. can be identified by its small, sub-spherical zooid; a C-shaped macronucleus; a ventrally located contractile vacuole; an aboral trochal band adjacent to the scopula; 16-18 silverlines between persitome and aboral trochal band, two between aboral trochal band and scopula. Vorticella paralima sp. n. can be identified by its ovoidal zooid; a J-shaped macronucleus; a dorsally positioned contractile vacuole; rows 1 and 2 of the infundibular polykinetid 3 proximally shortened; 26-35 silverlines from peristome to aboral trochal band, and 7-13 from aboral trochal band to scopula. The SSU rDNA genes of these four species were sequenced and their phylogeny was analyzed.


Assuntos
Oligoimenóforos/classificação , Oligoimenóforos/citologia , China , DNA de Protozoário/análise , Macronúcleo/fisiologia , Águas Salinas , Análise de Sequência de DNA , Especificidade da Espécie
19.
Mol Phylogenet Evol ; 132: 25-35, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30496843

RESUMO

Peritrichia is a large and distinctive assemblage of ciliated protists that was first observed by Antonie van Leeuwenhoek over 340 years ago. In the last two decades the evolutionary relationships of this subclass have been increasingly debated as morphological and molecular analyses have generated contrasting conclusions. In this study, we provide genomic-scale data from 12 typical representatives. We combine taxon- and gene-rich phylogenomic analyses, with up to 151 genes (43,956 amino acid residues) from 18 freshwater, brackish and marine isolates in order to assess the systematics and evolutionary history of the Peritrichia. The main findings were: (1) the subclass Peritrichia originates from the end of the Proterozoic to the Cambrian; (2) the monophyletic Peritrichia is sister to the Peniculia (represented by Paramecium) within the class Oligohymenophorea; (3) spasmin plays a significant role in peritrich evolution: we detected the spasmin gene in target ciliates and traced the molecular evolution of spasmin, a key spasmoneme component, together with phylogenetic relationships and morphology of the peritrichs. These findings provide evidence that spasmin is an important molecule to illustrate the phylogenetic position of Peritrichia within the class Oligohymenophorea, the monophyly of Peritrichia, and the diverse and rapid evolution of sessilid peritrichs.


Assuntos
Oligoimenóforos/classificação , Oligoimenóforos/genética , Filogenia , Proteínas Contráteis/genética , Evolução Molecular , Variação Genética , Genômica , Proteínas de Protozoários/genética , Especificidade da Espécie , Fatores de Tempo
20.
J Eukaryot Microbiol ; 66(3): 447-459, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30203898

RESUMO

During a survey of trichodinids in Chongqing, China, two populations of Trichodina reticulata Hirschmann & Partsch, 1955 were isolated from gills of the freshwater fishes, Carassius auratus and Ctenopharyngodon idellus, and 11 molecular samples containing small subunit (SSU) rDNA and internal transcribed spacer (ITS)-5.8S rDNA were newly sequenced. Both populations fell within the range of morphometry and corresponded well with the diagnostic morphological features of Trichodina reticulata Hirschmann & Partsch, 1955. It should be noted that one population possessed obvious central granules in the adhesive disc, while the other one did not. The detailed morphological redescription for these two populations is given in this work. Although some intraspecific differences were found, both populations were confirmed as Trichodina reticulata based on the morphological study and molecular data, including the sequence analysis of the primary and secondary structures of SSU rDNA, genetic distances and phylogenetic tree. Our study supports the assertion that central granules in the adhesive disc might be an auxiliary feature rather than a heritable character for determining taxonomic affiliations among trichodinids.


Assuntos
Carpas , Infecções por Cilióforos/veterinária , Doenças dos Peixes/parasitologia , Carpa Dourada , Oligoimenóforos/classificação , Animais , Sequência de Bases , China , Infecções por Cilióforos/parasitologia , DNA de Protozoário/análise , DNA Ribossômico/análise , DNA Espaçador Ribossômico/análise , Brânquias/parasitologia , Oligoimenóforos/citologia , Oligoimenóforos/genética , Alinhamento de Sequência
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