Yogsothoth knorrus gen. n., sp. n. and Y. carteri sp. n. (Yogsothothidae fam. n., Haptista, Centroplasthelida), with Notes on Evolution and Systematics of Centrohelids
Publication date: Available online 18 June 2018 Source:Protist Author(s): Yegor Shishkin, Daria Drachko, Vladimir I. Klimov, Vasily V. Zlatogursky Two closely related new species of centrohelid heliozoans with unusual morphology were studied with light and electron microscopy. Sequences of the 18S rRNA gene were also obtained and secondary structure of 18S rRNA molecule reconstructed. The cells, covered with inner siliceous plate scales formed colonies. The entire colony was surrounded with a thick layer of external scales. Inner scales were tabulate and had a patternless surface, except for the presence of an axial ...
Source: Protist - June 19, 2018 Category: Molecular Biology Source Type: research
The Uncoupled Assimilation of Carbon and Nitrogen from Urea and Glycine by the Bloom-forming Dinoflagellate Prorocentrum minimum
Publication date: Available online 5 June 2018 Source:Protist Author(s): Olga Matantseva, Ilya Pozdnyakov, Maren Voss, Iris Liskow, Sergei Skarlato The spread of harmful dinoflagellate blooms has been linked to the increasing availability of nitrogen, including its dissolved organic forms. The relationships between organic and inorganic nutrient uptake by dinoflagellates are not completely understood; moreover, it is not clear whether organic substances are used exclusively as nitrogen or also as carbon sources. We used laboratory culture experiments to investigate the concurrent uptake of glycine and nitrate by Pro...
Source: Protist - June 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: Available online 4 June 2018 Source:Protist Author(s): Rui Xiao, Xiang Li, Yi Zheng This 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 (∼5g/L dry cell mass, DCM) occurred under the cultivation conditions of T=25°C, glucose=30g/L, yeast extract/peptone (YEP)=4g/L, salinity=100% of seawater, pH=6-7, and rotation ...
Source: Protist - June 5, 2018 Category: Molecular Biology Source Type: research
Incomplete Reproductive Isolation Between Genetically Distinct Sympatric Clades of the Pennate Model Diatom Seminavis robusta
Publication date: Available online 29 May 2018 Source:Protist Author(s): Sam De Decker, Pieter Vanormelingen, Eveline Pinseel, Josefin Sefbom, Sien Audoor, Koen Sabbe, Wim Vyverman Incomplete 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 ...
Source: Protist - May 30, 2018 Category: Molecular Biology Source Type: research
The Little-known Freshwater Metopid Ciliate, Idiometopus turbo (Dragesco and Dragesco-Kern éis, 1986) nov. gen., nov. comb., Originally Discovered in Africa, Found on the Micronesian Island of Guam
Publication date: Available online 26 May 2018 Source:Protist Author(s): William Bourland, Johana Rotterová, Xiaotian Luo, Ivan Čepička Class Armophorea Lynn, 2004 includes two orders of mainly free-living anaerobic ciliates, Armophorida Jankowski, 1980 and Metopida Jankowski, 1980 and 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. Although n...
Source: Protist - May 27, 2018 Category: Molecular Biology Source Type: research
Is Myxomycetes (Amoebozoa) a Truly Ambiregnal Group? A Major Issue in Protist Nomenclature
Publication date: Available online 25 May 2018 Source:Protist Author(s): Anna Ronikier, Adam T. Halamski Myxomycetes 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; thu...
Source: Protist - May 25, 2018 Category: Molecular Biology Source Type: research
Diversity of Organellar Genomes in Non-photosynthetic Diatoms
This study clearly demonstrated not only the evolutionary trends of plastid genome reduction but also the linkage between plastid genome reduction and a biological change of nutrient requirements in Nitzschia. (Source: Protist)
Source: Protist - April 27, 2018 Category: Molecular Biology Source Type: research
Molecular Phylogeny and Morphology of Haplozoon ezoense n. sp. (Dinophyceae): A Parasitic Dinoflagellate with Ultrastructural Evidence of Remnant Non-photosynthetic Plastids
This study describes a novel species of Haplozoon, H. ezoense n. sp., a dinoflagellate parasite isolated from the intestines of Praxillella pacifica (Polychaeta). Trophonts (feeding stages) of H. ezoense n. sp. were isolated and studied with scanning and transmission electron microscopy, and molecular phylogenetic analyses was performed using 18S rDNA and 28S rDNA. Trophonts had an average length of 120μm, and were linear, forming a single longitudinal row comprising a trophocyte with a stylet, 14 gonocytes on average (width=10μm), and bulbous cells that we concluded were likely sporocytes. The surface of H. ezoense n. s...
Source: Protist - April 26, 2018 Category: Molecular Biology Source Type: research
The Hidden Diversity of Flagellated Protists in Soil
Publication date: Available online 25 April 2018 Source:Protist Author(s): Paul Christiaan Venter, Frank Nitsche, Hartmut Arndt Protists are among the most diverse and abundant eukaryotes in soil. However, gaps between described and sequenced protist morphospecies still present a pending problem when surveying environmental samples for known species using molecular methods. The number of sequences in the molecular PR2 database (∼130,000) is limited compared to the species richness expected (>1 million protist species) − limiting the recovery rate. This is important, since high throughput sequencing (HTS) me...
Source: Protist - April 25, 2018 Category: Molecular Biology Source Type: research
Revision of the Genus Chroomonas Hansgirg: The Benefits of DNA-containing Specimens
In this study, material of Hansgirg’s C. nordstedtii was subjected to PCR and to sequencing of two short DNA tags. These tags allowed for an unambiguous identification of the real C. nordstedtii in the phylogeny of the blue-green cryptophytes. The genus Chroomonas corresponds to subclade 1, whereas subclades 3 and 4 do not belong to Chroomonas, if Hemiselmis is maintained. Additional examination by light and scanning electron microscopy and by spectrophotometry demonstrate that subclade 1 comprises only cells with hexagonal periplast plates and PC 630, whereas rectangular periplast plates are found only in subclades 3 an...
Source: Protist - April 23, 2018 Category: Molecular Biology Source Type: research
First Ultrastructural and Molecular Phylogenetic Evidence from the Blastogregarines, an Early Branching Lineage of Plesiomorphic Apicomplexa
Publication date: Available online 23 April 2018 Source:Protist Author(s): Timur G. Simdyanov, Gita G. Paskerova, Andrea Valigurová, Andrei Diakin, Magdaléna Kováčiková, Joseph Schrével, Laure Guillou, Andrey A. Dobrovolskij, Vladimir V. Aleoshin Blastogregarines are poorly studied parasites of polychaetes superficially resembling gregarines, but lacking syzygy and gametocyst stages in the life cycle. Furthermore, their permanent multinuclearity and gametogenesis by means of budding considerably distinguish them from other parasitic Apicomplexa such as coccidians and haematozoans. The affiliation of blasto...
Source: Protist - April 23, 2018 Category: Molecular Biology Source Type: research
Epizoic and Apochlorotic Tursiocola species (Bacillariophyta) from the Skin of Florida Manatees (Trichechus manatus latirostris)
Publication date: Available online 16 April 2018 Source:Protist Author(s): Thomas A. Frankovich, Matt P. Ashworth, Michael J. Sullivan, Edward C. Theriot, Nicole I. Stacy Until now only one group of diatoms, the Bacillariaceae, was known to contain heterotrophic representatives. We show that a second group, represented by species in the genus Tursiocola, has undergone evolutionary loss of photosynthesis within the Bacillariophyta. Heterotrophy was evidenced by the presence of only apochlorotic cells in live and motile specimens. Three species of Tursiocola (T. bondei sp. nov., T. alata sp. nov., and T. gracilis sp. ...
Source: Protist - April 21, 2018 Category: Molecular Biology Source Type: research
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 - April 21, 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: Available online 21 April 2018 Source:Protist Author(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 Thewes Calcineurin 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 ...
Source: Protist - April 21, 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: Available online 14 April 2018 Source:Protist Author(s): Paul Christiaan Venter, Frank Nitsche, Anja Scherwass, Hartmut Arndt By 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 barcod...
Source: Protist - April 15, 2018 Category: Molecular Biology Source Type: research
