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 - July 6, 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 2018Source: ProtistAuthor(s): Timur G. Simdyanov, Gita G. Paskerova, Andrea Valigurová, Andrei Diakin, Magdaléna Kováčiková, Joseph Schrével, Laure Guillou, Andrey A. Dobrovolskij, Vladimir V. AleoshinBlastogregarines 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 blastogregarines ha...
Source: Protist - July 6, 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 2018Source: ProtistAuthor(s): Olga Matantseva, Ilya Pozdnyakov, Maren Voss, Iris Liskow, Sergei SkarlatoThe 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 Prorocentrum...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
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 2018Source: ProtistAuthor(s): Yegor Shishkin, Daria Drachko, Vladimir I. Klimov, Vasily V. ZlatogurskyTwo 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 rib. Out...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Nutritional Intake by Ectoplasmic Nets of Schizochytrium aggregatum (Labyrinthulomycetes, Stramenopiles)
Publication date: Available online 18 June 2018Source: ProtistAuthor(s): Izumi Iwata, Daiske HondaThraustochytrid 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 materia...
Source: Protist - July 6, 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 - July 6, 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 2018Source: ProtistAuthor(s): Irena Kaczmarska, James M. Ehrman, Nickolai A. Davidovich, Olga I. Davidovich, Yulia A. PodunayReproductive 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 siliceous sphe...
Source: Protist - July 6, 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 2018Source: ProtistAuthor(s): Gita G. Paskerova, Tatiana S. Miroliubova, Andrei Diakin, Magdaléna Kováčiková, Andrea Valigurová, Laure Guillou, Vladimir V. Aleoshin, Timur G. SimdyanovArchigregarines 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 system was rev...
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 2018Source: ProtistAuthor(s): Sebastian C. Treitli, Michael Kotyk, Naoji Yubuki, Eliška Jirounková, Jitka Vlasáková, Pavla Butovičová, Petr Šípek, Ivan Čepička, Vladimír HamplOxymonads 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 species and unused...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
The Hidden Diversity of Flagellated Protists in Soil
Publication date: July 2018Source: Protist, Volume 169, Issue 3Author(s): Paul Christiaan Venter, Frank Nitsche, Hartmut ArndtProtists 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) methods are used...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Editorial Board
Publication date: July 2018Source: Protist, Volume 169, Issue 3Author(s): (Source: Protist)
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Unprecedented Symbiont Eukaryote Diversity Is Governed by Internal Trophic Webs in a Wild Non-Human Primate
Publication date: July 2018Source: Protist, Volume 169, Issue 3Author(s): Justin J.S. Wilcox, Hope HollocherResearch on host-associated microbiomes has highlighted major divisions between the role of eukaryotes in free-living and symbiont systems. These trends call into question the relevance of macroecological processes to host-associated systems and the relative importance of parasitism, commensalism, and mutualism as evolutionary patterns across the domains of life. However, it is unclear as to whether these apparent differences reflect biological realities or methodologies in community characterization: free-living euk...
Source: Protist - July 6, 2018 Category: Molecular Biology Source Type: research
Grl1 Protein is a Candidate K Antigen in Tetrahymena thermophila
Publication date: July 2018Source: Protist, Volume 169, Issue 3Author(s): Takahide OtaIn Tetrahymena, K antigens associate only with mature basal bodies and are expected to play important roles in the morphogenesis and function of the membrane skeleton around basal bodies, but these proteins have not been identified and their functions are unknown. Commercially available anti-human Rho GDP-dissociation inhibitor α (RhoGDIα) antibody (sc-33201) was accidentally found to show very similar immunofluorescence staining patterns to those of anti-K antigen antibodies, such as 424A8 and 10D12 mouse monoclonal antibodies, in Tetr...
Source: Protist - July 6, 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 120 μm, and were linear, forming a single longitudinal row comprising a trophocyte with a stylet, an average of 14 gonocytes (width = 10 μm), and bulbous cells that we concluded were likely sporocytes. The...
Source: Protist - July 6, 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 - July 6, 2018 Category: Molecular Biology Source Type: research
