Systematic Redefinition of the Hypotricha (Alveolata, Ciliophora) Based on Combined Analyses of Morphological and Molecular Characters

Paiva, Thiago da Silva

doi:10.1016/j.protis.2020.125755

Cited by 27 publications

(12 citation statements)

References 167 publications

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“…Because the genus Anteholosticha was established based only on a combination of plesiomorphies in the absence of obvious synapomorphies, Berger (2003Berger ( , 2006 had hypothesized the nonmonophyly of Anteholosticha. Subsequently, the non-monophyly of Anteholosticha has been reported in many previous studies (Park et al, 2013;Zhao et al, 2015;Fan et al, 2016;Chen et al, 2018Chen et al, , 2020Paiva, 2020;Jung et al, 2021). Our analyses also confirm that Anteholosticha species are scattered among different branches inside the core urostylid assemblage.…”

Section: Phylogenetic Analyses Of the Genus Heterobakuella And Anteholostichasupporting

confidence: 87%

Taxonomy and Molecular Phylogeny of Two New Urostylid Ciliates (Protozoa: Ciliophora) From Chinese Wetlands and Establishment of a New Genus

et al. 2021

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Hypotrich ciliates with evolutionary novelties are continually being discovered, challenging the current taxonomic system and attracting increased attention. In the present work, two new urostylid ciliates, Heterobakuella bergeri gen. nov., sp. nov. and Anteholosticha perezuzae sp. nov., isolated from Chinese wetland samples, were identified based on morphology and 18S rRNA gene sequences. Heterobakuella gen. nov. is defined by three frontal cirri, single buccal cirrus, one parabuccal cirrus, midventral complex composed of cirral pairs and one cirral row, one left and two right marginal cirral rows, transverse and pretransverse cirri present, caudal and frontoterminal cirri absent. Heterobakuella can be easily distinguished from the morphologically most similar genus, Apobakuella, mainly by the single buccal cirrus (vs. one buccal cirral row) and one parabuccal cirrus (vs. several parabuccal cirral rows originated from different anlagen). Phylogenetic analyses show that H. bergeri branches within the clade formed by Bergeriella ovata, Monocoronella carnea, Anteholosticha gracilis, and Neourostylopsis spp., rather than the clade represented by Apobakuella. The other species, A. perezuzae, is mainly characterized by a distinctly slender body shape with an average length:width ratio about 7, distinctively shaped biconcave and greenish cortical granules, as well as one or two pretransverse cirri. Phylogenetic analyses indicate the genus Anteholosticha is non-monophyletic.

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Section: Phylogenetic Analyses Of the Genus Heterobakuella And Anteholostichasupporting

confidence: 87%

Taxonomy and Molecular Phylogeny of Two New Urostylid Ciliates (Protozoa: Ciliophora) From Chinese Wetlands and Establishment of a New Genus

et al. 2021

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“…It is rather difficult to infer the last common ancestor of hypotrichs from the 18S rRNA gene because the supporting values of their clades are low, and they are non-monophyletic (see Holosticha in Figure 6A ). Very likely, this is caused by undersampling, for instance, based on the recent redefinition on the Hypotrichia ( Da Silva Paiva, 2020 ), the genus Holosticha forms a clade within hypotrichs, but with the increase of taxon sampling, it showed a sister relationship to the clade composed of Oligotrichia and Choreotrichia ( Gao et al, 2016 ; Sheng et al, 2018 ).…”

Section: Discussionmentioning

confidence: 99%

Tunicothrix halophila n. sp., a Secondarily Oligomerized Parabirojimid Hypotrich (Ciliophora, Spirotrichea) From Hypersaline Costal Water in Korea

et al. 2021

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Tunicothrix halophila n. sp. was discovered in a hypersaline marine sample from Jeju Island, Korea. It is characterized by the highly reduced number of dorsal bristles. In addition, the main character of the genus Tunicothrix (e.g., alveolar layer) is absent/indistinct. To figure out its identity and phylogenetic relationship, we examined the new species based on modern morphological methods and molecular phylogenetic analyses. Since the parabirojimids are of basal position to core hypotrichs and a smaller data set could show incorrect phylogenetic relationships among the hypotrichs, we used a huge data set composed of 1,460 DNA sequences to infer the phylogenetic tree. The reduction of dorsal bristles is very likely a secondarily evolved character in hypotrichs, resulting in the independent phenotypic adaptation in the hypersaline ecosystems as shown in other hypersaline hypotrichs. Furthermore, the so-called right marginal row 1 in other congeners is found to produce a pretransverse and transverse cirrus and thus we recommend using the term frontoventral row. Based on our data, we can justify Tunicothrix halophila n. sp. as a new species; however, despite the phenotypic distinctiveness, we refrain to establish a new genus because of the missing data and the non-monophyly of Tunicothrix.

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“…The SSU rRNA gene is very conservative and it is generally known that it bears mainly information for deeper nodes of phylogenetic trees. Therefore, manifold studies pursued to improve the knowledge about phylogenetic interrelationships within the subclass Hypotrichia using mostly sequences of that gene (e.g., Luo et al, 2017Luo et al, , 2018Song and Shao, 2017;Lyu et al, 2018;Kim and Min, 2019;Chen et al, 2020;Dong et al, 2020;Paiva, 2020;Park et al, 2020;Wang J. et al, 2020;Xu et al, 2020). On the other hand, the ITS1-5.8S-ITS2 region as well as the LSU rRNA gene are much faster evolving parts of the rDNA operon and hence bear phylogenetic signal also for more recent divergences (Abraham et al, 2019).…”

Section: Multi-gene Phylogenetic Analyses Of the Family Pseudokeronopmentioning

confidence: 99%

“…A lot of attention has been therefore paid to their diversity, function and evolution (e.g., Bharti et al, 2019;Hu et al, 2019;Jung and Berger, 2019;Kaur et al, 2019;Luo et al, 2019;Wang et al, 2019;Yan et al, 2019;Gong et al, 2020;Shao et al, 2020;Sheng et al, 2020;Wang Y. R. et al, 2020;Zhang et al, 2020). Hypotrichs (subclass Hypotrichia Stein, 1859) are not only among the most differentiated ciliate groups, but also among the most confused ones in terms of their systematics and phylogeny (for reviews, see Berger, 1999Berger, , 2006Berger, , 2008Berger, , 2011Luo et al, 2017;Song and Shao, 2017;Luo et al, 2018;Lyu et al, 2018;Kim and Min, 2019;Chen et al, 2020;Dong et al, 2020;Paiva, 2020;Park et al, 2020;Wang J. et al, 2020;Xu et al, 2020). In the present study, we focus on the hypotrich family Pseudokeronopsidae, which was established by Borror and Wicklow (1983).…”

Section: Introductionmentioning

confidence: 99%

Systematics and Multi-Gene Phylogeny of the Subfamily Nothoholostichinae (Ciliophora, Hypotrichia), With Integrative Description of a New Marine Species Nothoholosticha luporinii n. sp.

et al. 2020

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Morphogenesis of ciliated protists attracts a lot of attention, because their huge morphological diversity is related to formation of ciliary structures during cell division. In the present work, the morphology and morphogenesis as well as the phylogenetic position of a new, marine hypotrich ciliate, Nothoholosticha luporinii n. sp., were investigated. The new species is characterized by having a combination of the following features: a bicorona whose anterior row contains four frontal cirri and posterior row includes only two cirri, a single buccal cirrus, midventral complex composed of about 30 cirral pairs, one pretransverse cirrus, 3–6 transverse cirri, one left and one right marginal cirral row; three bipolar dorsal kineties; contractile vacuole located in about 2/3 of the body length, two types of cortical granules, and many macronuclear nodules scattered throughout the cytoplasm. The morphogenesis of N. luporinii follows the ontogenetic mode of Pseudokeronopsis, a well-known and closely related genus except that the macronucleus fuses into a single mass in the middle fission stage. Phylogenetic analyses based on the rDNA operon classify Nothoholosticha in the family Pseudokeronopsidae and support the distinctness of the new taxon as well as the monophyletic origin of the subfamily Nothoholostichinae.

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Systematic Redefinition of the Hypotricha (Alveolata, Ciliophora) Based on Combined Analyses of Morphological and Molecular Characters

Cited by 27 publications

References 167 publications

Taxonomy and Molecular Phylogeny of Two New Urostylid Ciliates (Protozoa: Ciliophora) From Chinese Wetlands and Establishment of a New Genus

Taxonomy and Molecular Phylogeny of Two New Urostylid Ciliates (Protozoa: Ciliophora) From Chinese Wetlands and Establishment of a New Genus

Tunicothrix halophila n. sp., a Secondarily Oligomerized Parabirojimid Hypotrich (Ciliophora, Spirotrichea) From Hypersaline Costal Water in Korea

Systematics and Multi-Gene Phylogeny of the Subfamily Nothoholostichinae (Ciliophora, Hypotrichia), With Integrative Description of a New Marine Species Nothoholosticha luporinii n. sp.

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