Tropidoatractidae fam. nov., a Deep Branching Lineage of Metopida (Armophorea, Ciliophora) Found in Diverse Habitats and Possessing Prokaryotic Symbionts
We report a discovery of a novel family of anaerobic ciliates, Tropidoatractidae fam. nov. Phylogenetic analyses based on the 18S rRNA gene show that the family Tropidoatractidae corresponds to the previously reported clade of environmental sequences closely related to the lineage consisting of orders Metopida and Clevelandellida. The family comprises two genera, Tropidoatractus and Palmarella, and five species, two of which are newly described herein. Tropidoatractidae are cosmopolitan Metopida with sparse somatic and oral ciliature, deep, cup-like buccal cavity, and hyaline cortex with interkinetal ridges. Moreover, all ...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
New Taxa of Streptophyte Algae (Streptophyta) from Terrestrial Habitats Revealed Using an Integrative Approach
Publication date: July 2018Source: Protist, Volume 169, Issue 3Author(s): Tatiana Mikhailyuk, Alena Lukešová, Karin Glaser, Andreas Holzinger, Sabrina Obwegeser, Svetlana Nyporko, Thomas Friedl, Ulf KarstenTwo new genera (Streptosarcina and Streptofilum) and three new species (Streptosarcina arenaria, S. costaricana and Streptofilum capillatum) of streptophyte algae were detected in cultures isolated from terrestrial habitats of Europe and Central America and described using an integrative approach. Additionally, a strain isolated from soil in North America was identified as Hormidiella parvula and proposed as an epitype...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Chaetoceros pauciramosus sp. nov. (Bacillariophyceae), a Widely Distributed Brackish Water Species in the C. lorenzianus Complex
Publication date: Available online 5 July 2018Source: ProtistAuthor(s): Zuo Yi Chen, Nina Lundholm, Øjvind Moestrup, Janina Kownacka, Yang LiTo understand the diversity of the diatom genus Chaetoceros Ehrenberg, the C. lorenzianus complex was previously chosen as a model and three new species were described. In the present study, yet another new species, Chaetoceros pauciramosus sp. nov., was discovered from Chinese tropical waters and the temperate south-eastern Baltic Sea. In the latter locality it has been known since 2003 and identified as C. cf lorenzianus, and now found to comprise a dominating component of the autu...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Incomplete Reproductive Isolation Between Genetically Distinct Sympatric Clades of the Pennate Model Diatom Seminavis robusta
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Sam De Decker, Pieter Vanormelingen, Eveline Pinseel, Josefin Sefbom, Sien Audoor, Koen Sabbe, Wim VyvermanIncomplete reproductive isolation between genetically distinct taxa provides an interesting opportunity for speciation and adaptation studies. This phenomenon is well-described in macro-organisms, but less experimental evidence is available for unicellular eukaryotes. Here, we document the sympatric occurrence of genetically differentiated populations of the pennate model diatom Seminavis robusta in coastal subtidal biofilm communities and sho...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Is Myxomycetes (Amoebozoa) a Truly Ambiregnal Group? A Major Issue in Protist Nomenclature
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Anna Ronikier, Adam T. HalamskiMyxomycetes is one of the largest groups of protists belonging to Amoebozoa, with ca 1,000 species recognised and more than 4,000 names in use. Historically, myxomycetes were considered fungi or protozoans which, however, fell under the provisions of the former International Code of Botanical Nomenclature (ICBN), currently the International Code of Nomenclature for algae, fungi, and plants (ICN). Attempts to apply the International Code of Zoological Nomenclature (ICZN) to myxomycetes were rare and inconsistent; thus,...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Comprehensive Study of Cultivation Conditions and Methods on Lipid Accumulation of a Marine Protist, Thraustochytrium striatum
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Rui Xiao, Xiang Li, Yi ZhengThis research studied the influences of cultivation conditions (carbon/nitrogen source concentration, initial pH, salinity, and rotation speed) on cell growth and fatty acid (FA) production/composition of a marine protist, Thraustochytrium striatum. Fed-batch was also studied to improve cell growth and FA production. The optimum cell growth (∼5 g/L dry cell mass, DCM) occurred under the cultivation conditions of T = 25 °C, glucose = 30 g/L, yeast extract/peptone (YEP) = 4&n...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
The Little-known Freshwater Metopid Ciliate, Idiometopus turbo (Dragesco and Dragesco-Kernéis, 1986) nov. gen., nov. comb., Originally Discovered in Africa, Found on the Micronesian Island of Guam
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): William Bourland, Johana Rotterová, Xiaotian Luo, Ivan ČepičkaClass Armophorea Lynn, 2004 includes two orders of mainly free-living anaerobic ciliates, Armophorida Jankowski, 1980 and Metopida Jankowski, 1980 and, a third, the exclusively endosymbiotic Clevelandellida. Kahl described the majority of free-living metopid species early in the 20th century. Excepting Jankowski in the 1960’s, little further interest was shown in this group. Metopus turbo Dragesco and Dragesco-Kernéis, 1986, from a West African pond, was more recently described. Al...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Collimyces mutans gen. et sp. nov. (Rhizophydiales, Collimycetaceae fam. nov.), a New Chytrid Parasite of Microglena (Volvocales, clade Monadinia)
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Kensuke Seto, Yousuke DegawaChytrids are early diverging lineages of true fungi that reproduce with posteriorly uniflagellate zoospores. In aquatic ecosystems, parasitic chytrids of algae have important ecological roles by influencing the population dynamics of phytoplankton and transferring nutrients and energy from inedible algae to zooplankton via zoospores. Despite their ecological importance, information on parasitic chytrids is lacking in the current systematics of chytrids. Here, we investigated a novel chytrid culture KS100 that parasitizes...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Discrepancies Between Molecular and Morphological Databases of Soil Ciliates Studied for Temperate Grasslands of Central Europe
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Paul Christiaan Venter, Frank Nitsche, Anja Scherwass, Hartmut ArndtBy measuring the change in soil protist communities, the effect of human land use on grasslands can be monitored to promote sustainable ecosystem functioning. Protists form the active link in the rhizosphere between the plant roots and higher trophic organisms; however, only few morphological species and their ecological values have yet been described in this context. To investigate the communicability between morphological and molecular databases used in the molecular barcoding of...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Calcineurin Silencing in Dictyostelium discoideum Leads to Cellular Alterations Affecting Mitochondria, Gene Expression, and Oxidative Stress Response
Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Konstanze Kobel-Höller, Kevin Gley, Janina Jochinke, Kristina Heider, Verena Nadin Fritsch, Ha Viet Duc Nguyen, Timo Lischke, Renate Radek, Ria Baumgrass, Rupert Mutzel, Sascha ThewesCalcineurin is involved in development and cell differentiation of the social amoeba Dictyostelium discoideum. However, since knockouts of the calcineurin-encoding genes are not possible in D. discoideum it is assumed that the phosphatase also plays a crucial role during vegetative growth of the amoebae. Therefore, we investigated the role of calcineurin during vegeta...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Molecular and Morphological Diversity of the Oxymonad Genera Monocercomonoides and Blattamonas gen. nov
Publication date: Available online 30 June 2018 Source:Protist Author(s): Sebastian C. Treitli, Michael Kotyk, Naoji Yubuki, Eliška Jirounková, Jitka Vlasáková, Pavla Butovičová, Petr Šípek, Ivan Čepička, Vladimír Hampl Oxymonads are a group of flagellates living as gut symbionts of insects or vertebrates. They have several unique features, one of them being the absence of mitochondria. Diversity of this group is seriously understudied, which is particularly true for small species from the Polymastigidae family. We isolated 34 strains of oxymonads with Polymastigidae-like morphology from 24 host speci...
Source: Protist - July 1, 2018 Category: Molecular Biology Source Type: research
Fine structure and Molecular Phylogenetic Position of Two Marine Gregarines, Selenidium pygospionis sp. n. and S. pherusae sp. n., with Notes on the Phylogeny of Archigregarinida (Apicomplexa)
Publication date: Available online 28 June 2018 Source:Protist Author(s): Gita G. Paskerova, Tatiana S. Miroliubova, Andrei Diakin, Magdaléna Kováčiková, Andrea Valigurová, Laure Guillou, Vladimir V. Aleoshin, Timur G. Simdyanov Archigregarines are a key group for understanding the early evolution of Apicomplexa. Here we report morphological, ultrastructural, and molecular phylogenetic evidence from two archigregarine species: Selenidium pygospionis sp. n. and S. pherusae sp. n. They exhibited typical features of archigregarines. Additionally, an axial row of vacuoles of a presumably nutrient distribution sy...
Source: Protist - June 28, 2018 Category: Molecular Biology Source Type: research
Structure and Development of the Auxospore in Ardissonea crystallina (C. Agardh) Grunow Demonstrates Another Way for a Centric to Look Like a Pennate
Publication date: Available online 20 June 2018 Source:Protist Author(s): Irena Kaczmarska, James M. Ehrman, Nickolai A. Davidovich, Olga I. Davidovich, Yulia A. Podunay Reproductive development in Ardissonea crystallina revealed a unique mode of enlargement involving a combination of novel and known structures. In light microscopy, auxospores of this elongated polar centric diatom were superficially similar to the auxospores of pennates. With SEM we found three different components in the auxospore wall. In the youngest, nearly spherical cell-stage, the wall consisted only of a delicate veil containing minute silic...
Source: Protist - June 20, 2018 Category: Molecular Biology Source Type: research
Nutritional Intake by Ectoplasmic Nets of Schizochytrium aggregatum (Labyrinthulomycetes, Stramenopiles)
Publication date: Available online 18 June 2018 Source:Protist Author(s): Izumi Iwata, Daiske Honda Thraustochytrid cells attach to their food via ectoplasmic nets (ENs). Here, we analyzed the cause and effect relationship between the various forms and functions of ENs of Schizochytrium aggregatum. The ENs spread out over a large area forming a fine network to efficiently search for the experimental food source. After recognizing the experimental food source, the ENs that attached to the food source became thicker, and net elements developed. The thick ENs on the surface at the attachment site were enveloped in dense m...
Source: Protist - June 19, 2018 Category: Molecular Biology Source Type: research
Quantitative Response of Alexandrium catenella Cyst Dormancy to Cold Exposure
This study examines the effect of cold exposure on the duration of dormancy in Alexandrium catenella, a HAB dinoflagellate that causes paralytic shellfish poisoning (PSP). Mature, dormant cysts from Nauset Marsh (Cape Cod, MA USA) were stored at low but above freezing temperatures for up to six months. Dormancy status was then determined at regular intervals using a germination assay. Dormancy timing was variable among temperatures and was shorter in colder treatments, but the differences collapse when temperature and duration of storage are scaled by chilling-units (CU), a common horticultural predictor of plant and insec...
Source: Protist - June 19, 2018 Category: Molecular Biology Source Type: research
