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1.
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
2.
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
3.
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
4.
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
5.
Protist ; 171(3): 125740, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32544844

RESUMO

We report the discovery of three new species of freshwater metopid ciliates, Pileometopus lynni gen. et sp. nov., Castula flexibilis gen. et sp. nov., and Longitaenia australis gen. et sp. nov. Based on morphologic features and the 18S rRNA gene phylogeny, we transfer two known species of Metopus to the new genus Castula, as C. fusca (Kahl, 1927) comb. nov. and C. setosa (Kahl, 1927) comb. nov. and another known species is herein transferred to the new genus Longitaenia, as L. gibba (Kahl, 1927) comb. nov. Pileometopus is characterized by a turbinate body shape, a dorsal field of densely spaced dikinetids, a bipartite paroral membrane, and long caudal cilia. A distinctive morphologic feature of Castula species is long setae arising over the posterior third of the body (as opposed to a terminal tuft). Longitaenia spp. are characterized by an equatorial cytostome and long perizonal ciliary stripe relative to the cell length. Based on phylogenetic analyses of 18S rRNA gene sequences, we identify and briefly discuss strongly supported clades and intraspecific genetic polymorphism within the order Metopida.


Assuntos
Cilióforos/classificação , Filogenia , Cilióforos/citologia , Cilióforos/isolamento & purificação , Água Doce/microbiologia , Filogeografia , RNA Ribossômico 18S/genética
6.
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
7.
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
8.
Sci Rep ; 10(1): 628, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959793

RESUMO

Freshwater protists often harbor unicellular green algae within their cells. In ciliates, possibly because of large host cell sizes and the small size of algal coccoids, a single host cell typically contains more than a hundred algal cells. While surveying such algae-bearing protists on Minami Daito Jima Island in Japan, we found a green Loxodes ciliate (Loxodida, Karyorelictea) that contained one or two dozens of very large coccoid algae. We isolated one of these algae and analyzed its characteristics in detail. A small subunit (SSU) rDNA phylogeny indicated Pseudodidymocystis species (Scenedesmaceae, Chlorophyceae) to be the taxon closest to the alga, although it was clearly separated from this by 39 or more different sites (inclusive of gaps). SSU rRNA structure analyses indicated that these displacements included eight compensatory base changes (CBCs) and seven hemi-CBCs. We therefore concluded that this alga belongs to a separate genus, and described it as Pediludiella daitoensis gen. et sp. nov. The shape of the isolated and cultured P. daitoensis was nearly spherical and reached up to 30 µm in diameter. Chloroplasts were arranged peripherally and often split and elongated. Cells were often vacuolated and possessed a net-like cytoplasm that resembled a football (soccer ball) in appearance, which was reflected in the genus name.


Assuntos
Clorofíceas/citologia , Clorofíceas/genética , Clorófitas/citologia , Clorófitas/genética , Cilióforos/citologia , Clorofíceas/classificação , Cloroplastos , Citoplasma , DNA de Plantas/genética , DNA Ribossômico/genética , Água Doce , Japão , Filogenia , RNA de Plantas/genética
9.
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
10.
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
11.
Eur J Protistol ; 72: 125659, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31825791

RESUMO

Three species of tintinnines, namely Tintinnopsis tentaculata Nie and Cheng, 1947, Tintinnopsis orientalis Kofoid and Campbell, 1929, and Eutintinnus lususundae (Entz, 1885) Kofoid and Campbell, 1939, were isolated from coastal waters of China. The morphology of each was investigated based on observations of live and protargol-stained specimens, and their SSU rDNA- and LSU rDNA-based phylogenetic relationships were analyzed. The ciliary patterns of these species are revealed for the first time. Based on the original descriptions and data from the present study, an improved diagnosis is given for each species. Unlike its congeners, the second dorsal kinety of Eutintinnus lususundae is displaced below the left ciliary field, which may suggest that the second dorsal kinety is evolving into a posterior kinety by a migration process. The ventral kinety in Eutintinnus is redefined. A neotype is fixed for T. tentaculata to stabilize the species name objectively, mainly because of the unavailability of type material.


Assuntos
Cilióforos/classificação , Água do Mar/parasitologia , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , Filogenia , RNA Ribossômico 18S/genética , Subunidades Ribossômicas Maiores de Eucariotos/genética , Especificidade da Espécie
12.
J Eukaryot Microbiol ; 67(1): 115-124, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31523898

RESUMO

Six isolates of mineral-enveloped Strombidinopsis minima-like species were collected from the coastal waters across several regions in Korea. Morphological observations and molecular analyses were performed. The ribosomal DNA sequences (including small subunit ribosomal DNA, internal transcriber spacer 1-5.8S ribosomal DNA-internal transcriber spacer 2; and part of large subunit ribosomal DNA) of these six isolates were compared. Their morphological characteristics were also compared with those of S. minima populations reported. The marked genetic differences (with a similarity range of 96.85-98.48%) in SSU rDNA among these S. minima-like entities suggest the existence of multiple species. This finding is also supported by morphological variations detected in this study and reported in the literature (e.g. 15-32 collar membranelles in different populations). In addition, S. minima-like species are clustered with S. batos and S. sinicum, and therefore, our SSU rDNA results support previous results suggesting that the genus Strombidinopsis is not monophyletic in origin. Further collection of morphological and molecular data may facilitate the determination of a new genus carrying mineral-enveloped Strombidinopsis species.


Assuntos
Cilióforos/classificação , Variação Genética , Filogenia , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/análise , República da Coreia , Análise de Sequência de DNA
13.
J Eukaryot Microbiol ; 67(1): 54-65, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31356708

RESUMO

The morphology and morphogenesis of a new ciliate species, Neobakuella aenigmatica n. sp., which was discovered in an estuary in Korea, were investigated, using live observation, protargol impregnation, and scanning electron microscopy. This new species is characterized by a large (185-300 × 55-105 µm in vivo), elongate-ellipsoidal, flexible but not contractile body. It has ellipsoidal, yellowish cortical granules, 1.3 × 1.0 µm in size. The species has invariably 3 frontal and 2 frontoterminal cirri, about 5-10 buccal and 1-6 parabuccal cirri, 7 midventral rows, and 1 right and 2-4 left marginal rows. The outer left marginal row(s) consists of 1-7 short rows of cirri. The nuclear apparatus comprises 130 macronuclear nodules and 2 spherical micronuclei on average. The dorsal ciliature consists of 3 dorsal kineties. The leftmost left marginal row(s) likely develops from anlagen originating from both the rightmost and leftmost left marginal row(s). The molecular phylogenetic tree based on SSU rDNA suggests the nonmonophyly of the genus Neobakuella.


Assuntos
Cilióforos/classificação , Cilióforos/citologia , Cilióforos/crescimento & desenvolvimento , Cilióforos/ultraestrutura , DNA de Protozoário/análise , DNA Ribossômico/análise , Microscopia , Microscopia Eletrônica de Varredura , Filogenia , República da Coreia , Rios/parasitologia , Análise de Sequência de DNA
14.
J Eukaryot Microbiol ; 67(1): 140-143, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31278835

RESUMO

Triadinium was created to include Triadinium caudatum. Further, four other species were included, T. minimum, T. galea, T. elongatum, and T. magnum, all sharing a characteristic helmet-shaped body. Wolska and Grain argued that the inclusion of T. minimum and T. galea into Triadinium was done based on superficial morphological aspects, and established two new genera to accommodate these species: Circodinium and Gassovskiella. Although the phylogenetic relationships within Entodiniomorphida have been investigated by multiple authors, none of them discussed the evolutionary relationship of helmet-shaped entodiniomorphids. We performed molecular phylogenetics and revisited old literature digging for morphological data to explain our results. According to our analyses, the helmet-shaped body is homoplastic and may have evolved from at least three different entodiniomorphid ancestors. Circodinium minimum is phylogenetically related to members of Blepharocorythidae, T. caudatum emerged within Spirodiniidae and G. galea within Polydiniellidae. This phylogenetic hypothesis is partially supported by information on infraciliature and ultrastructure of C. minimum and T. caudatum. However, such morphological information is not available for polydiniellids. In order to shed some light into the evolution of the helmet-shaped ciliates, future works should focus to collect information on the infraciliature and the ultrastructure of Polydiniella mysorea and of other Triadinium species.


Assuntos
Evolução Biológica , Cilióforos/classificação , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/análise , Filogenia , RNA Ribossômico 18S/análise
15.
Eur J Protistol ; 71: 125629, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31520848

RESUMO

The morphology and ontogenesis of a novel stylonychid ciliate, Tetmemena pustulata indica nov. subspec., were investigated using live observation and protargol preparation. The new subspecies was isolated from a water sample collected from the Thane Creek, Mumbai, India. At first glance, T. pustulata indica looked very similar in morphology and ontogenesis to the well-known Tetmemena pustulata, however, on detailed investigation some non-overlapping features in the ciliature were identified, i.e., the numbers of cirri in marginal rows, adoral membranelles, and bristles in dorsal kineties. These morphometric differences justified the separation at subspecies level. Furthermore, the resting cysts are different, i.e., with smooth external layer in T. pustulata indica whereas spinous in the nominotypical subspecies T. pustulata pustulata. The Venezuelan population of T. pustulata described by Foissner corresponds very well with the Indian population in the ciliature; however, the information on the resting cyst is lacking for the former. Our study presents an example of a cyst subspecies among hypotrich ciliates, and thus extends the concept which has been mainly reported for spathidiids.


Assuntos
Cilióforos/classificação , Cilióforos/citologia , Rios/parasitologia , Índia , Especificidade da Espécie
16.
Nature ; 571(7766): 560-564, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292551

RESUMO

The biophysical relationships between sensors and actuators1-5 have been fundamental to the development of complex life forms. Swimming organisms generate abundant flows that persist in aquatic environments6-13, and responding promptly to external stimuli is key to survival14-19. Here we present the discovery of 'hydrodynamic trigger waves' in cellular communities of the protist Spirostomum ambiguum that propagate-in a manner similar to a chain reaction20-22-hundreds of times faster than their swimming speed. By coiling its cytoskeleton, Spirostomum can contract its long body by 60% within milliseconds23, experiencing accelerations that can reach forces of 14g. We show that a single cellular contraction (the transmitter) generates long-ranged vortex flows at intermediate Reynolds numbers that can, in turn, trigger neighbouring cells (the receivers). To measure the sensitivity to hydrodynamic signals in these receiver cells, we present a high-throughput suction-flow device for probing mechanosensitive ion channels24 by back-calculating the microscopic forces on the cell membrane. We analyse and quantitatively model the ultra-fast hydrodynamic trigger waves in a universal framework of antenna and percolation theory25,26, and reveal a phase transition that requires a critical colony density to sustain collective communication. Our results suggest that this signalling could help to organize cohabiting communities over large distances and influence long-term behaviour through gene expression (comparable to quorum sensing16). In more immediate terms, because contractions release toxins27, synchronized discharges could facilitate the repulsion of large predators or immobilize large prey. We postulate that numerous aquatic organisms other than protists could coordinate their behaviour using variations of hydrodynamic trigger waves.


Assuntos
Comunicação Celular , Cilióforos/citologia , Cilióforos/fisiologia , Hidrodinâmica , Natação/fisiologia , Movimentos da Água , Animais , Organismos Aquáticos/citologia , Organismos Aquáticos/genética , Organismos Aquáticos/fisiologia , Biofísica , Cilióforos/genética , Citoesqueleto/fisiologia , Comportamento Predatório , Reologia , Fatores de Tempo
17.
Eur J Protistol ; 70: 17-31, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31352233

RESUMO

Two new colonial sessilid species, Opercularia miaoxinensis spec. nov. and Epistylis conica spec. nov., were isolated from the pereopods of freshwater crayfish, Procambarus clarkii in Hubei Province, China from 2016 to 2017. Both species were investigated by living observation, protargol impregnation, and molecular methods. Opercularia miaoxinensis spec. nov. is morphologically characterized by the following characteristics: spindle-shaped zooid, zooid size of 48-74×20-35µm in vivo, contractile vacuole ventrally located above macronucleus, and dichotomously branched stalk. Epistylis conica spec. nov. is characterized by conical zooid shape, zooid size of 56-70×22-39µm in vivo, C-shaped macronucleus with transverse orientation, dorsally located contractile vacuole, and dichotomously branched stalk. To further identify both species, phylogenetic trees were constructed based on small subunit ribosomal DNA (SSU rDNA) and ITS1-5.8S-ITS2 sequences. Both results showed that E. conica spec. nov. was part of a clade consisting of the majority of Epistylis species. Surprisingly, O. miaoxinensis spec. nov. also clustered within this large clade of Epistylis species and had a distant relationship with the other Opercularia species. These findings challenged the distinguishing morphological characteristics between Epistylididae and Operculariidae.


Assuntos
Cilióforos/classificação , Filogenia , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , DNA Ribossômico/genética , Especificidade da Espécie
18.
Eur J Protistol ; 70: 1-16, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31176174

RESUMO

Although it is widely recognized that oligotrich ciliates are the dominant constituent of microzooplankton communities and perform key functions in energy flow and material cycling in marine microbial food webs, knowledge of their diversity is scant. In the present study, we investigate the oligotrich genera, Cyrtostrombidium and Apostrombidium, with emphasis on their morphology and evolutionary relationships. Three isolates were collected from coastal waters of northern and southern China including two new species, viz., Cyrtostrombidium paraboreale sp. n., Apostrombidium orientale sp. n., and Apostrombidium pseudokielum Xu et al., 2009. Cyrtostrombidium paraboreale sp. n. is characterized by possessing 64-98 cytopharyngeal rods and two macronuclear nodules. Apostrombidium orientale sp. n. is characterized by its somatic kinety consisting of five fragments including a horizontally orientated subterminal fragment and possessing conspicuously long dorsal cilia. Apostrombidium pseudokielum is redescribed based on the new population and a re-examination of the type material. Phylogenetic analyses were performed for the subclass Oligotrichia, incorporating SSU rRNA gene sequences of the three species investigated here. The results indicate that the genus Cyrtostrombidium is monophyletic with C. paraboreale sp. n. occupying the basal position. The genus Apostrombidium is not monophyletic as Varistrombidium kielum is nested within it.


Assuntos
Organismos Aquáticos/classificação , Cilióforos/classificação , Filogenia , Organismos Aquáticos/citologia , Organismos Aquáticos/genética , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , DNA Ribossômico/genética , Água do Mar/parasitologia , Especificidade da Espécie
19.
Protist ; 170(3): 283-286, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31181471

RESUMO

Many protists form cell colonies. Among them several are filter-feeders depending on suspended food particles such as bacteria. It has been suggested that the formation of colonies enhances feeding efficiency and implied that - in the case of colonial choanoflagellates - it was an adaptive trait that led to the evolution of metazoans. Here it is shown experimentally - for a colonial peritrich ciliate and for a choanoflagellate - that colony-formation does not enhance the efficiency of filter-feeding relative to solitary cells and that the adaptive significance of cell colony-formation must have some other explanation.


Assuntos
Coanoflagelados/fisiologia , Cilióforos/fisiologia , Coanoflagelados/citologia , Cilióforos/citologia , Comportamento Alimentar/fisiologia
20.
Zoolog Sci ; 36(3): 242-249, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31251493

RESUMO

The morphology and molecular phylogeny of Parabistichella multilineae sp. nov., which was discovered in soil from Gagye Beach, South Korea, were investigated. The new species is characterized as follows: body size about 200 × 47 µm in vivo, slenderly lanceolate and twisted; two ellipsoidal macronuclei and usually two globular micronuclei; two types of cortical granules; four or five frontoventral rows, of which rows 1 and 2 are conspicuously developed and rows 3 and 4 are fully extended; and caudal cirri are lacking. Phylogenetic analyses based on the SSU rDNA sequences showed that the new species clusters in a soft polytomy with P. variabilis and Uroleptoides magnigranulosus.


Assuntos
Cilióforos/citologia , Cilióforos/genética , Filogenia , Solo , Especificidade da Espécie
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