Redescription of \u3cem\u3eAtopospira galeata\u3c/em\u3e (Kahl, 1927) nov. comb. and \u3cem\u3eA. violacea\u3c/em\u3e (Kahl, 1926) nov. comb. with Redefinition of \u3cem\u3eAtopospira\u3c/em\u3e Jankowski, 1964 nov. stat. and \u3cem\u3eBrachonella\u3c/em\u3e Jankowski, 1964 (Ciliophora, Armophorida)

The taxonomy of the Metopidae (Ciliophora, Armophorida) remains poorly understood since most of its members have not been studied by modern morphologic and molecular methods. Recent molecular investigations have indicated that the two most species-rich genera, Metopus and Brachonella, are likely nonmonophyletic with at least one well-supported 18S rDNA clade comprised of a species from each of these genera (Brachonella galeata and Metopus violaceus). We investigated these two species with silver impregnation and scanning electron microscopy. Both taxa share important morphologic characteristics not described in other species of Metopus or Brachonella. These synapomorphies include: (1) a diplostichomonad paroral membrane, (2) a bipartite adoral zone with a short buccal part composed of ordinary membranelles and a longer distal part composed of much smaller membranelles bearing a single cilium or none and extending the same length as the perzonal ciliary stripe. We transfer Brachonella galeata(Kahl, 1927) Jankowski, 1964 and Metopus violaceus Kahl, 1926 to genus Atopospira Jankowski, 1964 nov. stat. Pending detailed morphologic and molecular characterization, Brachonella campanula, B. cydonia andB. pyriforma, B. intercedens, and B. lemani remain in Brachonella Jankowski 1964

Morphology and Phylogeny of a New Woodruffiid Ciliate, \u3cem\u3eEtoschophrya inornata\u3c/em\u3e sp. n. (Ciliophora, Colpodea, Platyophryida), with an Account on Evolution of Platyophryids

We studied the morphology, morphometry, resting cysts and molecular phylogeny of a new woodruffiid ciliate, Etoschophrya inornata, from ephemeral puddles and two lacustrine habitats in Idaho, North-west USA. Up to now, the genus Etoschophrya has included a single species, Etoschophrya oscillatoriophaga, from which our new form is distinguished by (i) the absence of interkinetal cortical granules and, consequently, the absence of extrusible red material in methyl green-pyronin stains, (ii) usually ≥5 adoral membranelles vs. usually four, (iii) greater length and length/width ratio, (iv) prominent cortical furrows vs. inconspicuous and (v) adaptation to non-saline semi-terrestrial and lacustrine habitats in the Nearctic vs. highly saline alkaline Afrotropic soil habitats. Resting cysts have two distinct membranes and a thick hyaline mucous pericyst layer. However, only one membrane persists in older cysts. Like its congener, Etoschophrya inornata feeds exclusively on filamentous cyanobacteria. The 18S rRNA gene sequence places this species in a strongly supported clade with Kuklikophrya ougandae basal to the other platyophryids. We include a morphologic cladistic analysis of platyophryid ciliates and present a hypothetical scenario for the evolution of the platyophryid oral structures

Protargol Synthesis: An In-House Protocol

The protargol staining method has proved to be indispensable for revealing the cellular structures of a variety of protozoa, especially the flagellates and ciliates. Protargol provides permanent stains of a variety of cellular structures: nuclei, extrusomes, basal bodies, and microfilamentous constituents of cells. Together with the older silver nitrate methods, protargol impregnations have provided the basis for the detailed descriptions of nearly all ciliates to date. The performance of commercially available preparations has varied widely. Recently, suppliers have stopped stocking the effective forms of protargol resulting in a worldwide shortage. Thus, it has become necessary for protistologists to explore on-site synthesis of this critically important agent. An optimum protocol for synthesis of protargol should be rapid, relatively inexpensive, simple enough to be done by non-chemists, and achievable without specialized equipment. In this article, the authors briefly review the interesting history of protargol and describe a protocol, based on the early studies of neuroanatomists, that yields a protargol producing impregnations of ciliates comparable to those obtained with previously available commercial preparations

\u3cem\u3eAgolohymena aspidocauda\u3c/em\u3e nov. gen., nov. spec., a Histophagous Freshwater Tetrahymenid Ciliate in the Family Deltopylidae (Ciliophora, Hymenostomatia), from Idaho (Northwest U.S.A.): Morphology, Ontogenesis and Molecular Phylogeny

Morphology, ontogeny and the molecular phylogeny of Agolohymena aspidocauda nov. gen., nov. spec., a new freshwater tetrahymenid ciliate from Idaho, U.S.A, are described. The ontogeny and histophagous mode of nutrition are similar to those of Deltopylum rhabdoides Fauré-Fremiet and Mugard, 1946. The new genus is placed with Deltopylum in the resurrected family Deltopylidae Song & Wilbert, 1989. We emend the diagnostic features of the family to include division by polytomy, right and left somatic kineties extending into the preoral suture, crook-shaped or sigmoid adoral membranelles 1 and 2, markedly reduced adoral membranelle 3 and a tetrahymenid silverline pattern. The main diagnostic features of the new genus are a disc-shaped caudal ciliary array and formation of two types of resting cysts, one smooth and the other bearing tangled tubular or cylindrical lepidosomes. Nuclear small subunit ribosomal RNA gene and mitochondrial cytochrome oxidase subunit 1 gene sequences place the new genus basal within the order Tetrahymenida, well separated from members of the family Tetrahymenidae (Lambornella and Tetrahymena) and also from other tetrahymenids (Colpidium, Dexiostoma, Glaucoma). The genetic divergences between this species and other genera in Tetrahymenida are large enough to suggest placement of the new genus in a separate family. This corroborates the morphological data, since the elaborate caudal ciliary array and the lepidosome-covered resting cyst of this species are not found in other Tetrahymenidae

Genealogical analyses of multiple loci of litostomatean ciliates (Protista, Ciliophora, Litostomatea)

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Phylogenetics and Evolution 66 (2012): 397-411, doi:10.1016/j.ympev.2012.06.024.The class Litostomatea is a highly diverse ciliate taxon comprising hundreds of free-living and endocommensal species. However, their traditional morphology-based classification conflicts with 18S rRNA gene phylogenies indicating (1) a deep bifurcation of the Litostomatea into Rhynchostomatia and Haptoria + Trichostomatia, and (2) body polarization and simplification of the oral apparatus as main evolutionary trends in the Litostomatea. To test whether 18S rRNA molecules provide a suitable proxy for litostomatean evolutionary history, we used eighteen new ITS1-5.8S rRNA-ITS2 region sequences from various free-living litostomatean orders. These single- and multiple-locus analyses are in agreement with previous 18S rRNA gene phylogenies, supporting that both 18S rRNA gene and ITS region sequences are effective tools for resolving phylogenetic relationships among the litostomateans. Despite insertions, deletions and mutational saturations in the ITS region, the present study shows that ITS1 and ITS2 molecules can be used to infer phylogenetic relationships not only at species level but also at higher taxonomic ranks when their secondary structure information is utilized to aid alignment.Financial support was provided by the Austrian Science Foundation (FWF Projects P-19699-B17 and P-20360-B17 to Wilhelm Foissner), the Slovak Scientific Grant Agency (VEGA Project 1/0600/11 to Peter Vd’ačný), and US NSF Grants (Projects MCB-0348341 and DEB-0816840 to Slava S. Epstein)

Phylogeny of the Ciliate Family Psilotrichidae (Protista, Ciliophora), a Curious and Poorly-Known Taxon, with Notes on Two Algae-Bearing Psilotrichids from Guam, USA

Background: The classification of the family Psilotrichidae, a curious group of ciliated protists with unique morphological and ontogenetic features, is ambiguous and poorly understood particularly due to the lack of molecular data. Hence, the systematic relationship between this group and other taxa in the subclass Hypotrichia remains unresolved. In this paper the morphology and phylogenetics of species from two genera of Psilotrichida are studied to shed new light on the phylogeny and species diversity of this group of ciliates. Results: The 18S rRNA gene sequences of species from two psilotrichid genera were obtained. In the phylogenetic trees, the available psilotrichid sequences are placed in a highly supported clade, justifying the establishment of the family Psilotrichidae. The morphology of two little-known species, packed with green algae, including a new species, Hemiholosticha kahli nov. spec., and Psilotrichides hawaiiensis Heber et al., 2018, is studied based on live observation, protargol impregnation, and scanning electron microscopy. Both species are easily recognized by their green coloration due to the intracellular algae, and a comprehensive discussion as to the possible roles of the intracellular algae is provided. Conclusions: The 18S rRNA gene phylogeny supports the morphological argument that Hemiholosticha, Psilotrichides and Urospinula belong to the same family, Psilotrichidae. However, the single-gene analysis, not surprisingly, does not resolve the deeper relationships of Psilotrichidae within the subclass Hypotrichia. Two littleknown psilotrichid genera with green algae were collected from the same puddle on the island of Guam, indicating a high species diversity and broader geographic distribution of this group of ciliates than previously supposed. Phylogenetic inferences from transcriptomic and/or genomic data will likely be necessary to better define the systematic position and evolution of the family Psilotrichidae. Further studies are also needed to clarify the role of the intracellular eyespot-bearing algae in these ciliates

Morphologic and Molecular Description of \u3cem\u3eMetopus fuscus\u3c/em\u3e Kahl from North America and New rDNA Sequences from Seven Metopids (Armophorea, Metopidae)

Most species in the large ciliate genus Metopus Claparède & Lachmann, 1858 lack detailed descriptions based on modern morphologic and molecular methods. This lack of data for the vast majority of species hampers application of a morphospecies approach to the taxonomy of Metopus and other armophorids. In this report we redescribe the large species, Metopus fuscus Kahl, 1927 based on in vivo observation, silver impregnation, scanning electron microscopy, and single-cell 18S rDNA sequencing of a freshwater North American (Idaho) population. Metopus fuscus invariably has a perinuclear envelope of endosymbiotic bacteria not found in other species. Unlike the original description of a single row of coarse granules between ciliary rows, the Idaho population has five loose rows of small interkinetal granules. We discuss the possible importance of this character in metopids. We also provide a phylogenetic analysis including seven other new metopid 18S rDNA sequences: Brachonella spiralis, B. galeata, Metopus laminarius, M. setosus, M. striatus, M. violaceus, Palmarella lata. Metopus fuscus and M. setosus form a fully supported clade, challenging previous morphospecies groupings. We discuss some ambiguities of armophorid morphologic terminology in the earlier literature. Our phylogenetic analysis of Idaho metopids indicates that the genera Metopus and Brachonella are both nonmonophyletic

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

Epidermal Growth Factor-Induced Stimulation of Proliferation and Gene Expression Changes in the Hypotrichous Ciliate, \u3cem\u3eStylonychia lemnae\u3c/em\u3e

Epidermal growth factor (EGF) induces proliferation of epidermal and epithelial tissues in mammals. However, the effect of EGF on the single-celled eukaryotes is not well characterized, especially in the protists. Ciliates, an important group of protists, are well characterized as both pollution indicators and model organisms for research. Stylonychia lemnae, is one of the most common free-living ciliates, widely distributed in ponds, rivers and marshes. Here, we report the role of EGF on cell proliferation stimulation in S. lemnae. The growth curve of S. lemnae was established, and the stimulation effect of EGF on the proliferation of S. lemnae was investigated. Based on the results, potential EGF receptors were identified in S. lemnae according to the conserved domains and gene expression. Differential gene expression revealed that EGF-induced genes in other organisms (e.g. antioxidant) also up-regulated in S. lemnae cells at propagation stages. In addition, our results showed that EGF could up-regulate the signal transduction-related processes in the decline stage of S. lemnae cells, indicating its potential function in apoptosis inhibition. In summary, this study reports findings of the first investigation of EGF effects in hypotrich ciliates, and establishes an additional system for the study of the molecular mechanisms of EGF actions in eukaryotic cell division and proliferation

Morphology, Ontogenesis and Molecular Characterization of \u3cem\u3eAtractos contortus\u3c/em\u3e Vörösváry, 1950 and \u3cem\u3eStichotricha aculeata\u3c/em\u3e Wrzesniowskiego, 1866 (Ciliophora, Stichotrichida) with Consideration of Their Systematic Positions

Atractos contortus, a rare highly spiralized hypotrich ciliate, has not been studied by modern methods. Atractos contortus and Stichotricha aculeata are currently assigned to the Spirofildae. A Canadian population of A. contortus and an Idaho population of Stichotricha aculeata, were characterized using live observation, silver impregnation, scanning electron microscopy, and 18S rDNA sequencing. Atractos contortus has two frontal and one buccal cirrus, two marginal and two ventral rows arranged in left-handed helices, and four dorsal kineties. Left and right marginal rows make two and a half and three turns; left and right ventral rows are shortened. Frontoterminal, postoral, transverse and caudal cirri are absent. During morphogenesis the parental adoral zone is completely retained. Cirral rows replicate by intrakinetal and de novo processes. New right marginal and right ventral rows arise from the parental right ventral row. The parental right marginal row is morphogenetically inactive. Dorsal kineties replicate apokinetally. The parental dorsomarginal kinety and some parental marginal cirri persist for some time after cytokinesis. Phylogenetically, A. contortus groups with Uroleptus species and not spirofilids. The Idaho S. aculeata matches populations from previous reports. Monophyly of the Spirofilidae is rejected. Placement of genus Atractos in the family, Atractosidae nov. nom. is proposed