The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Luciana F. Santoferrara - One of the best experts on this subject based on the ideXlab platform.
-
dartintinnus alderae n g n sp a brackish water tintinnid ciliophora Spirotrichea with dual ended lorica collapsibility
Journal of Eukaryotic Microbiology, 2018Co-Authors: Susan A Smith, George B Mcmanus, Wen Song, Weiwei Liu, Nelly A Gavrilova, Alexander V Kurilov, Luciana F. SantoferraraAbstract:A tintinnid ciliate isolated from waters of the Thames River (Connecticut, USA) is described through combined in vivo observation, protargol impregnation, and phylogenetic analysis. The novel genus Dartintinnus and its type species, D. alderae are distinct from established tintinnid taxa by a lorica that collapses on both anterior and posterior ends. Dartintinnus is placed in the family Eutintinnidae based on a hyaline, elongated lorica opened at both ends, a ciliary pattern including a ventral kinety, at least one dorsal kinety, and right, left and lateral fields, and a sister relationship with Eutintinnus in gene trees. Main differences between D. alderae and Eutintinnus species include a 5.5-6.5% divergence in the small subunit rRNA gene, the geometry of the lorica (resembling an isosceles tetrahedron when collapsed vs. a cylinder, respectively), the number of macronuclear nodules (two vs. four), and the number of dorsal kineties (one vs. usually two). Considering the features of the new genus, we improve the diagnosis of the family Eutintinnidae, including the presence of a lateral ciliary field that had been overlooked in some Eutintinnus species. This work exemplifies the potential for novel diversity, even in these relatively well-studied protists, and the importance of an integrated approach for the description of tintinnid taxa.
-
phylogeny classification and diversity of choreotrichia and oligotrichia ciliophora Spirotrichea
Molecular Phylogenetics and Evolution, 2017Co-Authors: Luciana F. Santoferrara, Viviana V Alder, George B McmanusAbstract:Ciliated protists in the subclasses Choreotrichia and Oligotrichia are major components of marine plankton. Despite their ecological relevance, there are uncertainties in their systematics and diversity. We retrieved and curated all the GenBank ribosomal DNA (rDNA) sequences from these groups, which were analyzed in two ways. The first approach was based on morphologically-identified sequences (including those of two families and six genera newly studied here by single-cell sequencing), and aimed at improving phylogenetic inferences using concatenated sequences of three rDNA loci. Based on phylogenetic and morphological support, we update the taxonomic classification of these subclasses into 23 families, including the re-established Favellidae. We also propose an informal naming system for incertae sedis taxa, namely Tintinnopsis and five related genera that are spread among eleven lineages. The second approach included unidentified environmental sequences, and was used to explore potentially novel diversity in these subclasses. Our results support high proportions of both synonyms in tintinnids and uncharacterized taxa in choreotrichids and oligotrichs. One previously unidentified, environmental clade is here linked to our new Leegaardiellidae sequences. Our curation of almost 4000 rDNA sequences exemplifies known issues of public repositories, and suggests caution in both the use and contribution to these unique resources for evolutionary and diversity studies.
-
unexpected biodiversity of ciliates in marine samples from below the photic zone
Molecular Ecology, 2016Co-Authors: Jeandavid Grattepanche, Luciana F. Santoferrara, George B Mcmanus, Laura A KatzAbstract:Marine microbial eukaryotes play critical roles in planktonic food webs and have been described as most diverse in the photic zone where productivity is high. We used high-throughput sequencing (HTS) to analyse the spatial distribution of planktonic ciliate diversity from shallow waters ( 800 m depth) along a 163 km transect off the coast of New England, USA. We focus on ciliates in the subclasses Oligotrichia and Choreotrichia (class Spirotrichea), as these taxa are major components of marine food webs. We did not observe the decrease of diversity below the photic zone expected based on productivity and previous analyses. Instead, we saw an increase of diversity with depth. We also observed that the ciliate communities assessed by HTS cluster by depth layer and degree of water column stratification, suggesting that community assembly is driven by environmental factors. Across our samples, abundant OTUs tend to match previously characterized morphospecies while rare OTUs are more often undescribed, consistent with the idea that species in the rare biosphere remain to be characterized by microscopy. Finally, samples taken below the photic zone also reveal the prevalence of two uncharacterized (i.e. lacking sequenced morphospecies) clades - clusters X1 and X2 - that are enriched within the nano-sized fraction (2-10 μm) and are defined by deletions within the region of the SSU-rDNA analysed here. Together, these data reinforce that we still have much to learn about microbial diversity in marine ecosystems, especially in deep-waters that may be a reservoir for rare species and uncharacterized taxa.
-
Updating Biodiversity Studies in Loricate Protists: The Case of the Tintinnids (Alveolata, Ciliophora, Spirotrichea)
The Journal of eukaryotic microbiology, 2016Co-Authors: Luciana F. Santoferrara, Viviana A Alder, Jun Gong, Charles Bachy, Young-ok Kim, Alessandro Saccà, Inácio Domingos Da Silva Neto, Michaela C. Strüder-kypke, Alan WarrenAbstract:Species determination is crucial in biodiversity research. In tintinnids, identification is based almost exclusively on the lorica, despite its frequent intraspecific variability and interspecific similarity. We suggest updated procedures for identification and, depending on the aim of the study, further steps to obtain morphological, molecular, and ecological data. Our goal is to help improving the collection of information (e.g. species re-/descriptions and DNA barcodes) that is essential for generating a natural tintinnid classification and a reliable reference for environmental surveys. These suggestions are broadly useful for protistologists because they exemplify data integration, quality/effort compromise, and the need for scientific collaborations.
-
pyrosequencing for assessing diversity of eukaryotic microbes analysis of data on marine planktonic ciliates and comparison with traditional methods
Environmental Microbiology, 2014Co-Authors: Luciana F. Santoferrara, Jeandavid Grattepanche, Laura A Katz, George B McmanusAbstract:Summary Assessing microbial diversity requires analysis of all three domains of life, including eukaryotic microbes. We examined the diversity of two ecologically important clades of microbial eukaryotes, ciliates in the subclasses Oligotrichia and Choreotrichia (class Spirotrichea), by comparing pyrosequencing to Sanger-sequenced clone libraries and microscopy. Using samples from a large temperate estuary (Long Island Sound, USA), we gained three major insights. First, richness estimates varied by up to one order of magnitude either using different criteria for pyrosequence processing or among pyrosequencing, cloning and microscopy, while taxon identification was almost always coherent. Error-correcting algorithms for pyrosequences (‘denoising’) reduced discrepancies in richness but also removed known morphospecies from the data. Second, although most of the pyrosequenced operational taxonomic units (OTUs) were distributed within known orders and families, we found evidence of a previously uncharacterized or unknown clade even in these ciliate lineages that have a rich history of morphological description. Third, pyrosequencing allowed the detection of OTUs that were either dominant or extremely rare in different samples. Our findings confirm the potential of pyrosequencing for quantifying microbial diversity, but also highlight the importance of careful evaluation of pyrosequence processing for using this method to address ecological questions.
Viviana A Alder - One of the best experts on this subject based on the ideXlab platform.
-
Updating Biodiversity Studies in Loricate Protists: The Case of the Tintinnids (Alveolata, Ciliophora, Spirotrichea)
The Journal of eukaryotic microbiology, 2016Co-Authors: Luciana F. Santoferrara, Viviana A Alder, Jun Gong, Charles Bachy, Young-ok Kim, Alessandro Saccà, Inácio Domingos Da Silva Neto, Michaela C. Strüder-kypke, Alan WarrenAbstract:Species determination is crucial in biodiversity research. In tintinnids, identification is based almost exclusively on the lorica, despite its frequent intraspecific variability and interspecific similarity. We suggest updated procedures for identification and, depending on the aim of the study, further steps to obtain morphological, molecular, and ecological data. Our goal is to help improving the collection of information (e.g. species re-/descriptions and DNA barcodes) that is essential for generating a natural tintinnid classification and a reliable reference for environmental surveys. These suggestions are broadly useful for protistologists because they exemplify data integration, quality/effort compromise, and the need for scientific collaborations.
-
utility of genetic markers and morphology for species discrimination within the order tintinnida ciliophora Spirotrichea
Protist, 2013Co-Authors: Luciana F. Santoferrara, Viviana A Alder, George B McmanusAbstract:We evaluated the small- and large-subunit rDNA (SSU and LSU, respectively) for their ability to discriminate morphospecies of tintinnid ciliates. Multiple individuals from 29 morphospecies were identified according to microscopically-observed characteristics of the lorica, and then sequenced for both loci (21 new species for SSU and all of them new for LSU). Sequences from public databases were included in our analyses, and two hypervariable SSU regions (V4 and V9) were separately examined. Of the four regions, LSU is the most useful as a potential barcoding tool. It showed a gap in distances within and between species, and discriminated the maximum number of phylotypes (86% at 1% cut-off). SSU and V4 were less consistent, sometimes lumping together very distinctive morphospecies, even at the 1% level of sequence divergence. V9 was the least reliable marker in delimitating morphospecies. The agreement in sequences and morphology suggests that the lorica is useful for species discrimination, even in agglomerated forms. However, the observation of both genetically constant yet polymorphic groups of species, as well as similar morphospecies with divergent sequences, indicates that previous taxonomic schemes are complementary to the emerging molecular database.
-
phylogeny of the order tintinnida ciliophora Spirotrichea inferred from small and large subunit rrna genes
Journal of Eukaryotic Microbiology, 2012Co-Authors: Viviana A Alder, Luciana F. Santoferrara, George B McmanusAbstract:Concatenated sequences of small- and large-subunit rRNA genes were used to infer the phylogeny of 29 species in six genera of Tintinnida. We confirmed previous results on the positions of major clusters and the grouping of various genera, including Stenosemella, the paraphyletic Tintinnopsis, the newly investigated Helicostomella, and some species of the polyphyletic Favella. Tintinnidium and Eutintinnus were found to be monophyletic. This study contributes to tintinnid phylogenetic reconstruction by increasing both the number of species and the range of genetic markers analyzed.
Weibo Song - One of the best experts on this subject based on the ideXlab platform.
-
the all data based evolutionary hypothesis of ciliated protists with a revised classification of the phylum ciliophora eukaryota alveolata
Scientific Reports, 2016Co-Authors: Feng Gao, Jun Gong, Alan Warren, Ping Sun, Qianqian Zhang, Miao Miao, Jie Huang, Weibo SongAbstract:The phylum Ciliophora plays important roles in a wide range of biological studies. However, the evolutionary relationships of many groups remain unclear due to a lack of sufficient molecular data. In this study, molecular dataset was expanded with representatives from 55 orders and all major lineages. The main findings are: (1) 14 classes were recovered including one new class, Protocruziea n. cl.; (2) in addition to the two main branches, Postciliodesmatophora and Intramacronucleata, a third branch, the Mesodiniea, is identified as being basal to the other two subphyla; (3) the newly defined order Discocephalida is revealed to be a sister clade to the euplotids, strongly suggesting the separation of discocephalids from the hypotrichs; (4) the separation of mobilids from the peritrichs is not supported; (5) Loxocephalida is basal to the main scuticociliate assemblage, whereas the thigmotrichs are placed within the order Pleuronematida; (6) the monophyly of classes Phyllopharyngea, Karyorelictea, Armophorea, Prostomatea, Plagiopylea, Colpodea and Heterotrichea are confirmed; (7) ambiguous genera Askenasia, CyclotrichiumParaspathidium and Plagiocampa show close affiliation to the well known plagiopyleans; (8) validity of the subclass Rhynchostomatia is supported, and (9) the systematic positions of Halteriida and Linconophoria remain unresolved and are thus regarded as incertae sedis within Spirotrichea.
-
Phylogeny of three choreotrich genera (Protozoa, Ciliophora, Spirotrichea), with morphological, morphogenetic and molecular investigations on three strobilidiid species
Zoologica Scripta, 2012Co-Authors: Weiwei Liu, Alan Warren, Xiaofeng Lin, Weibo SongAbstract:Liu, W., Yi, Z., Lin, X., Warren, A. & Song, W. (2012). Phylogeny of three choreotrich genera (Protozoa, Ciliophora, Spirotrichea), with morphological, morphogenetic and molecular investigations on three strobilidiid species. —Zoologica Scripta, 41, 417–434. The phylogenetic relationships among three strobilidiid genera, namely Strobilidium, Rimostrombidium and Pelagostrobilidium, are investigated using a combination of morphological, morphogenetic and molecular data. The results indicate that all three genera belong to the same lineage, in which Rimostrombidium evolved first and Strobilidium and Pelagostrobilidium derived later. Improved genus diagnoses for Rimostrombidium and Pelagostrobilidium are supplied. The curved kinety 2 and the caudal spiralling of some somatic kineties are confirmed as generic characters for Pelagostrobilidium and Strobilidium, respectively. In addition, the morphology and morphogenesis of three species, namely R. veniliae (Montagnes & Taylor, 1994) Petz et al., 1995, P. paraepacrum sp. n. and P. minutum sp. n., isolated from the South China Sea are described. Pelagostrobilidium paraepacrum sp. n. is characterized by the presence of six somatic kineties, 30–32 external and two internal membranelles. Pelagostrobilidium minutum sp. n. is characterized by its extremely small body size, four somatic kineties, and in having one internal and 19–21 external membranelles. Rimostrombidium conicum Kahl, 1932 is transferred to the genus Pelagostrobilidium as P. conicum (Kahl, 1932) comb. nov.
-
further consideration of the phylogeny of some traditional heterotrichs protista ciliophora of uncertain affinities based on new sequences of the small subunit rrna gene
Journal of Eukaryotic Microbiology, 2009Co-Authors: Miao Miao, Weibo Song, John C Clamp, Khaled A S Alrasheid, Abdulaziz A Alkhedhairy, Saud AlarifiAbstract:The systematic relationships and taxonomic positions of the traditional heterotrich genera Condylostentor, Climacostomum, Fabrea, Folliculina, Peritromus, and Condylostoma, as well as the licnophorid genus Licnophora, were re-examined using new data from sequences of the gene coding for small subunit ribosomal RNA. Trees constructed using distance-matrix, Bayesian inference, and maximum-parsimony methods all showed the following relationships: (1) the "traditional" heterotrichs consist of several paraphyletic groups, including the current classes Heterotrichea, Armophorea and part of the Spirotrichea; (2) the class Heterotrichea was confirmed as a monophyletic assemblage based on our analyses of 31 taxa, and the genus Peritromus was demonstrated to be a peripheral group; (3) the genus Licnophora occupied an isolated branch on one side of the deepest divergence in the subphylum Intramacronucleata and was closely affiliated with spirotrichs, armophoreans, and clevelandellids; (4) Condylostentor, a recently defined genus with several truly unique morphological features, is more closely related to Condylostoma than to Stentor; (5) Folliculina, Eufolliculina, and Maristentor always clustered together with high bootstrap support; and (6) Climacostomum occupied a paraphyletic position distant from Fabrea, showing a close relationship with Condylostomatidae and Chattonidiidae despite of modest support.
-
does kiitricha protista ciliophora Spirotrichea belong to euplotida or represent a primordial spirotrichous taxon with suggestion to establish a new subclass protohypotrichia
International Journal of Systematic and Evolutionary Microbiology, 2009Co-Authors: Chen Shao, Denis H. Lynn, Weibo Song, Zigui Chen, Mann Kyoon ShinAbstract:The genus Kiitricha was long assumed to be the most primordial taxon in the Stichotrichia [hypotrichs sensu lato (s. l.)] based on its morphological features and was considered to be an intermediate between heterotrichs and the traditional hypotrichous assemblage. In order to evaluate the phylogenetic position of Kiitricha within the Hypotrichia, we sequenced the small-subunit rRNA gene and the alpha-tubulin gene for a Qingdao population of Kiitricha marina. Phylogenetic trees were constructed and compared to morphological and morphogenetic data. The results show that (i) Kiitricha is positioned near Phacodinium, both of which always form a sister clade to the assemblage including Stichotrichia, Hypotrichia, Oligotrichia and Choreotrichia, (ii) Kiitricha, which may represent an intermediate between heterotrichs (s. l.) and the Stichotrichia–Hypotrichia complex, is probably an ancestor-like form of the latter group and (iii) in contrast to morphological characters, both molecular and ontogenetic data support the separation of Kiitricha from the hypotrichs (s. l.). Thus, Kiitricha might be placed in the class Spirotrichea at about subclass level, next to Phaconidiidia, Hypotrichia and Stichotrichia, which supports the establishment of a new subclass Protohypotrichia n. subclass within the class Spirotrichea, with characterizations including slightly differentiated somatic ciliature (i.e. cirri on the ventral side generally uniform and non-grouped, no clearly defined marginal cirral rows, ciliature on the dorsal side mixed with cirri and dikinetids, no clearly differentiated dorsal kineties) and a unique but intermediate morphogenetic pattern of cortical structures between Hypotrichia and Stichotrichia.
-
systematic position of discocephalus like ciliates ciliophora Spirotrichea inferred from ssu rdna and ontogenetic information
International Journal of Systematic and Evolutionary Microbiology, 2008Co-Authors: Chen Shao, Alan Warren, Weibo Song, Khaled A S Alrasheid, Saleh Alquraishy, Saleh A Alfarraj, Xiaofeng LinAbstract:The Prodiscocephalus-like ciliates, or discocephalines, are cephalized organisms that are traditionally considered to be hypotrichs (sensu lato) but whose precise systematic position has long been uncertain. The main reasons for this are that these organisms exhibit several intermediate morphological and morphogenetic features and that hitherto none has been investigated using molecular methods. In the present study, the cortical development of Prodiscocephalus borrori was observed during binary division and this can be summarized as follows: (i) in the parental adoral zone of membranelles, only the posterior end is renewed by dedifferentiation of the old structures; (ii) the oral primordium in the opisthe occurs de novo on the cell surface as seen in other typical stichotrichs; (iii) in both dividers, the undulating membranes anlage does not split longitudinally in the usual way but, instead, divides transversely to form the paroral and endoral membranes; (iv) usually seven frontoventral transverse cirral anlagen are formed in the primary mode which then divide into two sets, one each for the proter and opisthe; (v) both left and right marginal rows divide into two parts, thus giving rise to a post-lateral marginal segment at the posterior end of each; (vi) invariably five caudal cirri are formed at the posterior end of the three rightmost dorsal kinety anlagen. Thus, it was found that, like other related discocephalines, P. borrori exhibits more similarities to stichotrichs than to euplotids. Based on a combination of morphological and morphogenetic data, a phylogenetic tree was constructed which suggests that the discocephalines group within the stichotrichs and separate from the euplotids. In addition, the complete small-subunit rRNA gene (SSU rDNA) of P. borrori was sequenced and analysed. In the resulting SSU rDNA tree, the discocephalines represent an intermediate group between the euplotids and the Stichotrichia-Oligotrichia-Choreotrichia assemblage, albeit with low bootstrap support. From these data, we conclude that the discocephalines might be a divergent, or possibly an ancestral, group within the Stichotrichia. Furthermore, our findings further support the suggestion that these organisms should be considered as a distinct order, i.e. Discocephalida Wicklow, 1982, in the subclass Stichotrichia Small & Lynn, 1985.
George B Mcmanus - One of the best experts on this subject based on the ideXlab platform.
-
Incubation and grazing effects on spirotrich ciliate diversity inferred from molecular analyses of microcosm experiments - Fig 4
2019Co-Authors: Jeandavid Grattepanche, George B Mcmanus, Doris L. Juarez, Cameah C. Wood, Laura A KatzAbstract:Principal Coordinate analyses of HTS data show (1) clustering of distinct SAR and Spirotrichea communities that are related to size fractions (circle and triangle) and (2) a tendency to group by phytoplankton treatments for the SAR community (3) but not for the ciliate community. The Unifrac dissimilarity index has been computed for these analyses. The same analyses were carried out with the Bray-Curtis index and gave the same pattern.
-
dartintinnus alderae n g n sp a brackish water tintinnid ciliophora Spirotrichea with dual ended lorica collapsibility
Journal of Eukaryotic Microbiology, 2018Co-Authors: Susan A Smith, George B Mcmanus, Wen Song, Weiwei Liu, Nelly A Gavrilova, Alexander V Kurilov, Luciana F. SantoferraraAbstract:A tintinnid ciliate isolated from waters of the Thames River (Connecticut, USA) is described through combined in vivo observation, protargol impregnation, and phylogenetic analysis. The novel genus Dartintinnus and its type species, D. alderae are distinct from established tintinnid taxa by a lorica that collapses on both anterior and posterior ends. Dartintinnus is placed in the family Eutintinnidae based on a hyaline, elongated lorica opened at both ends, a ciliary pattern including a ventral kinety, at least one dorsal kinety, and right, left and lateral fields, and a sister relationship with Eutintinnus in gene trees. Main differences between D. alderae and Eutintinnus species include a 5.5-6.5% divergence in the small subunit rRNA gene, the geometry of the lorica (resembling an isosceles tetrahedron when collapsed vs. a cylinder, respectively), the number of macronuclear nodules (two vs. four), and the number of dorsal kineties (one vs. usually two). Considering the features of the new genus, we improve the diagnosis of the family Eutintinnidae, including the presence of a lateral ciliary field that had been overlooked in some Eutintinnus species. This work exemplifies the potential for novel diversity, even in these relatively well-studied protists, and the importance of an integrated approach for the description of tintinnid taxa.
-
phylogeny classification and diversity of choreotrichia and oligotrichia ciliophora Spirotrichea
Molecular Phylogenetics and Evolution, 2017Co-Authors: Luciana F. Santoferrara, Viviana V Alder, George B McmanusAbstract:Ciliated protists in the subclasses Choreotrichia and Oligotrichia are major components of marine plankton. Despite their ecological relevance, there are uncertainties in their systematics and diversity. We retrieved and curated all the GenBank ribosomal DNA (rDNA) sequences from these groups, which were analyzed in two ways. The first approach was based on morphologically-identified sequences (including those of two families and six genera newly studied here by single-cell sequencing), and aimed at improving phylogenetic inferences using concatenated sequences of three rDNA loci. Based on phylogenetic and morphological support, we update the taxonomic classification of these subclasses into 23 families, including the re-established Favellidae. We also propose an informal naming system for incertae sedis taxa, namely Tintinnopsis and five related genera that are spread among eleven lineages. The second approach included unidentified environmental sequences, and was used to explore potentially novel diversity in these subclasses. Our results support high proportions of both synonyms in tintinnids and uncharacterized taxa in choreotrichids and oligotrichs. One previously unidentified, environmental clade is here linked to our new Leegaardiellidae sequences. Our curation of almost 4000 rDNA sequences exemplifies known issues of public repositories, and suggests caution in both the use and contribution to these unique resources for evolutionary and diversity studies.
-
unexpected biodiversity of ciliates in marine samples from below the photic zone
Molecular Ecology, 2016Co-Authors: Jeandavid Grattepanche, Luciana F. Santoferrara, George B Mcmanus, Laura A KatzAbstract:Marine microbial eukaryotes play critical roles in planktonic food webs and have been described as most diverse in the photic zone where productivity is high. We used high-throughput sequencing (HTS) to analyse the spatial distribution of planktonic ciliate diversity from shallow waters ( 800 m depth) along a 163 km transect off the coast of New England, USA. We focus on ciliates in the subclasses Oligotrichia and Choreotrichia (class Spirotrichea), as these taxa are major components of marine food webs. We did not observe the decrease of diversity below the photic zone expected based on productivity and previous analyses. Instead, we saw an increase of diversity with depth. We also observed that the ciliate communities assessed by HTS cluster by depth layer and degree of water column stratification, suggesting that community assembly is driven by environmental factors. Across our samples, abundant OTUs tend to match previously characterized morphospecies while rare OTUs are more often undescribed, consistent with the idea that species in the rare biosphere remain to be characterized by microscopy. Finally, samples taken below the photic zone also reveal the prevalence of two uncharacterized (i.e. lacking sequenced morphospecies) clades - clusters X1 and X2 - that are enriched within the nano-sized fraction (2-10 μm) and are defined by deletions within the region of the SSU-rDNA analysed here. Together, these data reinforce that we still have much to learn about microbial diversity in marine ecosystems, especially in deep-waters that may be a reservoir for rare species and uncharacterized taxa.
-
Ciliate diversity and distribution across an environmental and depth gradient in Long Island
2016Co-Authors: Mary Doherty, George B Mcmanus, Maiko Tamura, Barbara A. Costas, Mark E. Ritchie, Laura A KatzAbstract:The nature and extent of microbial biodiversity remain controversial with persistent debates over patterns of distributions (i.e. cosmopolitanism versus endemism) and the processes that structure these patterns (neutrality versus selection). We used culture-independent approaches to address these issues focusing on two groups of ciliates, the Oligo-trichia (Spirotrichea) and Choreotrichia (Spirotrichea) across an environmental gradient. We assessed SSU rDNA diversity in ciliate communities at six stations in Long Island Sound spanning the frontal region that separates the fresher Connecticut River outflow plume from the open Sound. As in previous studies, we find one abundant cosmopolitan species (Strom-bidium biarmatum), a few moderately abundan
Alan Warren - One of the best experts on this subject based on the ideXlab platform.
-
morphology and phylogeny of four marine or brackish water spirotrich ciliates protozoa ciliophora from china with descriptions of two new species
European Journal of Protistology, 2020Co-Authors: Alan Warren, Xiaotian Luo, Chunyu Lian, Yan Zhao, Jiamei JiangAbstract: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. (C) 2019 Elsevier GmbH. All rights reserved.
-
morphological studies on four brackish water ciliates of the class Spirotrichea protista ciliophora
Journal of Ocean University of China, 2019Co-Authors: Yuan Song, Yongqiang Liu, Bo Pan, Xiaotian Luo, Wen Song, Alan WarrenAbstract:We reinvestigate the morphology of two oligotrich and two hypotrich ciliates collected from the coasts of north and south China, viz., Parallelostrombidium obesum Liu et al., 2015, Spirostrombidium apourceolare Liu et al., 2013, Protogastrostyla pulchra (Pereyaslawzewa, 1886) Gong et al., 2007, and Uncinata bradburyae (Gong et al., 2001) Luo et al., 2015. All the populations match well with the original samples identified in previous studies. Supplemental taxonomic data were supplied for these four species of the new populations. The species Parallelostrombidium obesum is characterised by its dorsal-ventrally flattened body shape with anterior and posterior ends transversely truncating, as well as two thigmotactic membranelles and girdle kinety that spirals around the cell one and a half times. Spirostrombidium apourceolare is characterised by its elongate ellipsoidal and dorsal-ventrally flattened body shape, two thigmotactic membranelles, about 11-27 ovoid macronuclear nodules, and girdle kinety that spirals around the cell twice with two undulations. Protogastrostyla pulchra is characterised by its elongate body shape and unique, caudally located food vacuole. Based on the new populations, we described the smaller cortical granules, clustered around dorsal bristles for the first time. The new population of Uncinata bradburyae shares the diagnostic features with the type population, which include prominent beak-like projection in anterior region, the conspicuous gap of adoral zone, proximalmost adoral membranelles distinctly elongated, and infraciliature.
-
assessment of heavy metal toxicity in four species of freshwater ciliates Spirotrichea ciliophora from delhi india
Current Science, 2017Co-Authors: Jeeva Susan Abraham, S Sripoorna, Ashish Kumar Choudhary, Ravi Toteja, Renu Gupta, Seema Makhija, Alan WarrenAbstract:In vitro laboratory experiments were conducted to determine the toxicity (per cent survival and LC 50 ) of essential and non-essential heavy metals (cadmium, copper, nickel, lead and zinc) in four spirotrich ciliates: Euplotes sp., Notohymena sp., Pseudourostyla sp. and Tetmemena sp. isolated from three different freshwater ecosystems in the Delhi region, India. The toxicity of the heavy metals was found to vary among the different ciliates. Copper was most toxic (24 h-LC 50 value ranged between 0.125 and 0.74 mg/l) and zinc was least toxic (24 h LC50 value ranged between 46.98 and 144.32 mg/l) to each of the ciliates. Of the four ciliates, Notohymena sp. had the highest tolerance limit to three heavy metals (Cu, Cd and Pb) out of the five tested. This study shows the high potentiality of using freshwater ciliates for monitoring the intensity and potency of ecological damage caused by heavy metals in aquatic ecosystems.
-
the all data based evolutionary hypothesis of ciliated protists with a revised classification of the phylum ciliophora eukaryota alveolata
Scientific Reports, 2016Co-Authors: Feng Gao, Jun Gong, Alan Warren, Ping Sun, Qianqian Zhang, Miao Miao, Jie Huang, Weibo SongAbstract:The phylum Ciliophora plays important roles in a wide range of biological studies. However, the evolutionary relationships of many groups remain unclear due to a lack of sufficient molecular data. In this study, molecular dataset was expanded with representatives from 55 orders and all major lineages. The main findings are: (1) 14 classes were recovered including one new class, Protocruziea n. cl.; (2) in addition to the two main branches, Postciliodesmatophora and Intramacronucleata, a third branch, the Mesodiniea, is identified as being basal to the other two subphyla; (3) the newly defined order Discocephalida is revealed to be a sister clade to the euplotids, strongly suggesting the separation of discocephalids from the hypotrichs; (4) the separation of mobilids from the peritrichs is not supported; (5) Loxocephalida is basal to the main scuticociliate assemblage, whereas the thigmotrichs are placed within the order Pleuronematida; (6) the monophyly of classes Phyllopharyngea, Karyorelictea, Armophorea, Prostomatea, Plagiopylea, Colpodea and Heterotrichea are confirmed; (7) ambiguous genera Askenasia, CyclotrichiumParaspathidium and Plagiocampa show close affiliation to the well known plagiopyleans; (8) validity of the subclass Rhynchostomatia is supported, and (9) the systematic positions of Halteriida and Linconophoria remain unresolved and are thus regarded as incertae sedis within Spirotrichea.
-
Updating Biodiversity Studies in Loricate Protists: The Case of the Tintinnids (Alveolata, Ciliophora, Spirotrichea)
The Journal of eukaryotic microbiology, 2016Co-Authors: Luciana F. Santoferrara, Viviana A Alder, Jun Gong, Charles Bachy, Young-ok Kim, Alessandro Saccà, Inácio Domingos Da Silva Neto, Michaela C. Strüder-kypke, Alan WarrenAbstract:Species determination is crucial in biodiversity research. In tintinnids, identification is based almost exclusively on the lorica, despite its frequent intraspecific variability and interspecific similarity. We suggest updated procedures for identification and, depending on the aim of the study, further steps to obtain morphological, molecular, and ecological data. Our goal is to help improving the collection of information (e.g. species re-/descriptions and DNA barcodes) that is essential for generating a natural tintinnid classification and a reliable reference for environmental surveys. These suggestions are broadly useful for protistologists because they exemplify data integration, quality/effort compromise, and the need for scientific collaborations.