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https://www.readbyqxmd.com/read/28582680/evolutionary-relationship-of-the-scale-bearing-kraken-incertae-sedis-monadofilosa-cercozoa-rhizaria-combining-ultrastructure-data-and-a-two-gene-phylogeny
#1
Kenneth Dumack, Alexander P Mylnikov, Michael Bonkowski
The genus Kraken represents a distinct lineage of filose amoebae within the Cercozoa. Currently a single species, Kraken carinae, has been described. SSU rDNA phylogeny showed an affiliation to the Cercomonadida, branching with weak support at its base, close to Paracercomonas, Metabolomonas, and Brevimastigomonas. Light microscopical analyses showed several unique features of the genus Kraken, but ultrastructure data were lacking. In this study, K. carinae has been studied by electron microscopy, these data conjoined with a two-gene phylogeny were used to give more insight into the evolutionary relationship of the genus Kraken within Cercozoa...
July 2017: Protist
https://www.readbyqxmd.com/read/28554153/how-far-do-ciliate-flagships-sail-a-proposed-gondawanaland-endemic-species-at-anchor-in-idaho-soils
#2
William Bourland
In terms of protist biogeography, "flagship species" (Foissner 2005) have been defined as those so remarkable or "showy" that they are unlikely to be overlooked when present in a given habitat. On this basis, flagship species have been suggested as an ideal or ultimate test for the existence of protist endemism. One example of a flagship ciliate is the terrestrial lepidosome-bearing trachelophyllid, Luporinophrys micelae, previously thought to be a Gondwanan endemic. This report comprises a morphologic description of two populations of L...
July 2017: Protist
https://www.readbyqxmd.com/read/28554152/aviisotricha-hoazini-n-gen-n-sp-the-morphology-and-molecular-phylogeny-of-an-anaerobic-ciliate-from-the-crop-of-the-hoatzin-opisthocomus-hoazin-the-cow-among-the-birds
#3
Christian F Bardele, Sigrid Schultheiß, Denis H Lynn, André-Denis G Wright, Maria Gloria Dominguez-Bello, Nestor E Obispo
The hoatzin is the only known avian species that has evolved a foregut fermentation system similar to that of ruminant animals. Due to the closeness of the bird's fermentation chamber, the crop, to the bird's beak it exudes an unpleasant odour; therefore, the hoatzin is called the "cow among the birds". In addition to Eubacteria and Archaea, responsible for digestion of the vegetation they consume, the bird's crop contains a holotrich ciliate, described here for the first time in detail. Cytological staining of this isotrichid-like ciliate with the Chatton-Lwoff and Protargol staining procedures, as well as SEM and TEM, justified the establishment of the new genus Aviisotricha n...
July 2017: Protist
https://www.readbyqxmd.com/read/28499132/multiple-dictyostelid-species-destroy-biofilms-of-klebsiella-oxytoca-and-other-gram-negative-species
#4
Dean Sanders, Katarzyna D Borys, Fikrullah Kisa, Sheryl A Rakowski, Marcela Lozano, Marcin Filutowicz
Dictyostelids are free-living phagocytes that feed on bacteria in diverse habitats. When bacterial prey is in short supply or depleted, they undergo multicellular development culminating in the formation of dormant spores. In this work, we tested isolates representing four dictyostelid species from two genera (Dictyostelium and Polysphondylium) for the potential to feed on biofilms preformed on glass and polycarbonate surfaces. The abilities of dictyostelids were monitored for three hallmarks of activity: 1) spore germination on biofilms, 2) predation on biofilm enmeshed bacteria by phagocytic cells and 3) characteristic stages of multicellular development (streaming and fructification)...
July 2017: Protist
https://www.readbyqxmd.com/read/28499131/polyphyly-in-the-thecate-amoeba-genus-lecythium-chlamydophryidae-tectofilosida-cercozoa-redescription-of-its-type-species-l-hyalinum-description-of-l-jennyae-sp-nov-and-the-establishment-of-fisculla-gen-nov-and-fiscullidae-fam-nov
#5
Kenneth Dumack, Paul Mausbach, Mona Hegmann, Michael Bonkowski
Although testate amoebae have attracted great interest of protistologists for more than a century, some groups, especially those with a hyaline, organic test (=theca) are still poorly known. One of those is the genus Lecythium Hertwig et Lesser, 1874. Only recently Lecythium spp. were characterized by morphological and molecular means, but data on the type species Lecythium hyalinum Hertwig et Lesser, 1874, was still lacking. In this study, we screened for L. hyalinum in freshwater samples of Germany and the Netherlands...
July 2017: Protist
https://www.readbyqxmd.com/read/28495413/the-central-vacuole-of-the-diatom-phaeodactylum-tricornutum-identification-of-new-vacuolar-membrane-proteins-and-of-a-functional-di-leucine-based-targeting-motif
#6
Viktoria Schreiber, Josefine Dersch, Katharina Puzik, Oliver Bäcker, Xiaojuan Liu, Simone Stork, Julian Schulz, Thomas Heimerl, Andreas Klingl, Stefan Zauner, Uwe G Maier
Diatoms are unicellular organisms evolved by secondary endosymbiosis. Although studied in many aspects, the functions of vacuolar-like structures of these organisms are rarely investigated. One of these structures is a dominant central vacuole-like compartment with a marbled phenotype, which is supposed to represent a chrysolaminarin-storing and carbohydrate mobilization compartment. However, other functions as well as targeting of proteins to this compartment are not shown experimentally. In order to study trafficking of membrane proteins to the vacuolar membrane, we scanned the genome for intrinsic vacuolar membrane proteins and used one representative for targeting studies...
July 2017: Protist
https://www.readbyqxmd.com/read/28477515/soil-dna-extraction-procedure-influences-protist-18s-rrna-gene-community-profiling-outcome
#7
Susana S Santos, Inês Nunes, Tue K Nielsen, Samuel Jacquiod, Lars H Hansen, Anne Winding
Advances in sequencing technologies allow deeper studies of the soil protist diversity and function. However, little attention has been given to the impact of the chosen soil DNA extraction procedure to the overall results. We examined the effect of three acknowledged DNA recovery methods, two manual methods (ISOm-11063, GnS-GII) and one commercial kit (MoBio), on soil protist community structures obtained from different sites with different land uses. Results from 18S rRNA gene amplicon sequencing suggest that DNA extraction method significantly affect the replicate homogeneity, the total number of operational taxonomic units (OTUs) recovered and the overall taxonomic structure and diversity of soil protist communities...
July 2017: Protist
https://www.readbyqxmd.com/read/28472733/in-vitro-inhibition-of-leishmania-attachment-to-sandfly-midguts-and-ll-5-cells-by-divalent-metal-chelators-anti-gp63-and-phosphoglycans
#8
Rodrigo Pedro Soares, Ellen Cristina Félix Altoé, Vítor Ennes-Vidal, Simone M da Costa, Elizabeth Ferreira Rangel, Nataly Araújo de Souza, Vanderlei Campos da Silva, Petr Volf, Claudia Masini d'Avila-Levy
Leishmania braziliensis and Leishmania infantum are the causative agents of cutaneous and visceral leishmaniasis, respectively. Several aspects of the vector-parasite interaction involving gp63 and phosphoglycans have been individually assayed in different studies. However, their role under the same experimental conditions was not studied yet. Here, the roles of divalent metal chelators, anti-gp63 antibodies and purified type I phosphoglycans (PGs) were evaluated during in vitro parasite attachment to the midgut of the vector...
July 2017: Protist
https://www.readbyqxmd.com/read/28371652/the-symbiotic-bacterium-fuels-the-energy-metabolism-of-the-host-trypanosomatid-strigomonas-culicis
#9
Ana Carolina Loyola-Machado, Allan Cézar Azevedo-Martins, Carolina Moura Costa Catta-Preta, Wanderley de Souza, Antonio Galina, Maria Cristina M Motta
The mutualistic relationship between trypanosomatids and their respective endosymbiotic bacteria represents an excellent model for studying metabolic co-evolution since the symbiont completes essential biosynthetic routes of the host cell. In this work, we investigated the influence of the endosymbiont on the energy metabolism of Strigomonas culicis by comparing the wild strain with aposymbiotic protists. The bacterium maintains a frequent and close association with glycosomes, which are distributed around the prokaryote...
February 28, 2017: Protist
https://www.readbyqxmd.com/read/28262587/diversity-of-the-photosynthetic-paulinella-species-with-the-description-of-paulinella-micropora-sp-nov-and-the-chromatophore-genome-sequence-for-strain-kr01
#10
Duckhyun Lhee, Eun Chan Yang, Jong Im Kim, Takuro Nakayama, Giuseppe Zuccarello, Robert A Andersen, Hwan Su Yoon
The thecate filose amoeba Paulinella chromatophora is a good model organism for understanding plastid organellogenesis because its chromatophore was newly derived from an alpha-cyanobacterium. Paulinella chromatophora was the only known photosynthetic Paulinella species until recent studies that suggested a species level of diversity. Here, we described a new photosynthetic species P. micropora sp. nov. based on morphological and molecular evidence from a newly established strain KR01. The chromatophore genome of P...
February 14, 2017: Protist
https://www.readbyqxmd.com/read/28104538/clarification-of-photorespiratory-processes-and-the-role-of-malic-enzyme-in-diatoms
#11
Aubrey Davis, Raffaela Abbriano, Sarah R Smith, Mark Hildebrand
Evidence suggests that diatom photorespiratory metabolism is distinct from other photosynthetic eukaryotes in that there may be at least two routes for the metabolism of the photorespiratory metabolite glycolate. One occurs primarily in the mitochondria and is similar to the C2 photorespiratory pathway, and the other processes glycolate through the peroxisomal glyoxylate cycle. Genomic analysis has identified the presence of key genes required for glycolate oxidation, the glyoxylate cycle, and malate metabolism, however, predictions of intracellular localization can be ambiguous and require verification...
February 2017: Protist
https://www.readbyqxmd.com/read/28064061/description-of-hyalodiscus-flabellus-sp-nov-vampyrellida-rhizaria-and-identification-of-its-bacterial-endosymbiont-candidatus-megaira-polyxenophila-rickettsiales-alphaproteobacteria
#12
Sebastian Hess
The genus Hyalodiscus Hertwig and Lesser, 1874 comprises naked freshwater amoebae with a unique set of characters, namely a vibrant orange-red colour, a discoid or fan-shaped morphology, and a characteristic rolling locomotion. Some species feed on the chloroplasts of green algae and were regarded as relatives of Vampyrella Cienkowski, 1865. However, because of striking morphological differences and the lack of molecular data, the exact relationship of Hyalodiscus to vampyrellids is still obscure. Here, I describe Hyalodiscus flabellus sp...
February 2017: Protist
https://www.readbyqxmd.com/read/28061382/budding-of-the-alveolate-alga-vitrella-brassicaformis-resembles-sexual-and-asexual-processes-in-apicomplexan-parasites
#13
Zoltán Füssy, Petra Masařová, Jitka Kručinská, Heather J Esson, Miroslav Oborník
Ease of cultivation and availability of genomic data promoted intensive research of free-living phototrophic relatives of apicomplexans, i.e. Chromera velia and Vitrella brassicaformis. Chromera and Vitrella differ significantly in their physiology, morphology, phylogenetic position and genomic features, but Vitrella has not gained as much attention. Here we describe two types of Vitrella zoosporangia. One contains zoospores surrounded by roughly structured matter, with an intracytoplasmic axoneme predicted to develop into a mature flagellum upon spore release, similarly to Plasmodium microgametes; in the second type, cells concurrently bud off the center of the sporangium, surrounded by smooth matter, and flagella develop extracellularly...
February 2017: Protist
https://www.readbyqxmd.com/read/28056380/shedding-light-on-the-polyphyletic-thecate-amoeba-genus-plagiophrys-transition-of-some-of-its-species-to-rhizaspis-tectofilosida-thecofilosea-cercozoa-and-the-establishment-of-sacciforma-gen-nov-and-rhogostomidae-fam-nov-cryomonadida-thecofilosea-cercozoa
#14
Kenneth Dumack, Hüsna Öztoprak, Lioba Rüger, Michael Bonkowski
For over a century testate amoebae have been a favoured group of interest for protistologists, however there is still an endless amount of unanswered questions. The genus Plagiophrys, Claparède and Lachmann 1859, is still one of the unresolved mysteries as it comprises species with high morphological diversity of which no molecular data are available. To shed light on the phylogeny and taxonomy of Plagiophrys we (a) cultured four isolates of three Plagiophrys morphospecies and provided morphological observations (b) obtained three new SSU RNA gene sequences and conducted phylogenetic analyses of the Thecofilosea and (c) did intensive literature research, showing that Plagiophrys is polyphyletic...
February 2017: Protist
https://www.readbyqxmd.com/read/28043008/description-of-phytomonas-oxycareni-n-sp-from-the-salivary-glands-of-oxycarenus-lavaterae
#15
Emily A Seward, Jan Votýpka, Petr Kment, Julius Lukeš, Steven Kelly
Phytomonas spp. (phytomonads) are a diverse and globally distributed group of unicellular eukaryotes that parasitize a wide range of plants and are transmitted by insect hosts. Here we report the discovery and characterisation of a new species of Phytomonas, named Phytomonas oxycareni n. sp., which was obtained from the salivary glands of the invasive species of true bug Oxycarenus lavaterae (Heteroptera). The new Phytomonas species exhibits a long slender promastigote morphology and can be found both within the lumen of the insect host's salivary glands as well as within the cells of the salivary gland itself...
February 2017: Protist
https://www.readbyqxmd.com/read/28043007/molecular-and-morphological-investigations-of-the-stauros-bearing-raphid-pennate-diatoms-bacillariophyceae-craspedostauros-e-j-cox-and-staurotropis-t-b-b-paddock-and-their-relationship-to-the-rest-of-the-mastogloiales
#16
Matt P Ashworth, Christopher S Lobban, Andrzej Witkowski, Edward C Theriot, Meeshal J Sabir, Mohammad N Baeshen, Nahid H Hajarah, Nabih A Baeshen, Jamal S Sabir, Robert K Jansen
Several lineages of raphe-bearing diatoms possess a "stauros," which is a transverse, usually thickened area free of pores across the center of the valve. It has been suggested that this structure has evolved several times across the raphid diatoms, but we have noticed similarities beyond the stauros between two marine genera-Craspedostauros and Staurotropis-in the structure of their pore occlusions. We have isolated, cultured and extracted DNA from several strains of both genera to infer the phylogenetic relationship between these taxa, as well as test the suggested relationship of Craspedostauros to Achnanthes and Mastogloia based on plastid morphology...
February 2017: Protist
https://www.readbyqxmd.com/read/27951467/cobalamin-independent-methionine-synthase-distribution-and-influence-on-vitamin-b12-growth-requirements-in-marine-diatoms
#17
Kelsey A Ellis, Natalie R Cohen, Carly Moreno, Adrian Marchetti
The requirement for cobalamin (vitamin B12) in microalgae is primarily a function of the type of methionine synthase present within their gene repertoires. Our study validates this concept through analysis of the distribution of B12-independent methionine synthase in ecologically relevant diatom genera, including the closely related bloom-forming genera Pseudo-nitzschia and Fragilariopsis. Growth and gene expression analysis of the vitamin B12-requiring version of the methionine synthase enzyme, METH, and the B12-independent version, METE, demonstrate that it is the presence of the METE gene which allows Fragilariopsis cylindrus to grow in the absence of B12...
February 2017: Protist
https://www.readbyqxmd.com/read/27912101/the-cytoskeleton-architecture-of-algivorous-protoplast-feeders-viridiraptoridae-rhizaria-indicates-actin-guided-perforation-of-prey-cell-walls
#18
Anna Busch, Sebastian Hess
Several distantly related, phagotrophic microeukaryotes share the remarkable ability to perforate foreign cell walls in a well-defined pattern to acquire protoplast material as food. The underlying cellular processes, especially the local application of cell wall degrading agents, are still unexplored. We examined the distribution of F-actin and alpha-tubulin in the algivorous, viridiraptorid amoeboflagellates Orciraptor agilis and Viridiraptor invadens over their life histories using phalloidin conjugates and immunolocalization...
February 2017: Protist
https://www.readbyqxmd.com/read/27888714/a-cryptic-marine-ciliate-feeds-on-progametes-of-noctiluca-scintillans
#19
Shuwen Zhang, Kit Yu Karen Chan, Zhuo Shen, Shunyan Cheung, Michael R Landry, Hongbin Liu
The dinoflagellate Noctiluca scintillans (Noctiluca) has the ability to reproduce sexually, which may help to increase or restore its population size during periods of blooms or environmental stress. Here, we documented for the first time a marine ciliate Strombidium sp. that feeds on Noctiluca's progametes undergoing stages 5 to 9 of nuclear division. This ciliate frequently swam on or around gametogenic and some vegetative Noctiluca cells. The ciliates associated with gametogenic cells had significantly lower swimming speed and changed direction more frequently than those associated with vegetative cells, which overall increased their time spent around the food patches (progametes)...
February 2017: Protist
https://www.readbyqxmd.com/read/28285260/microsatellite-markers-for-population-genetic-applications-in-the-domoic-acid-producing-diatom-pseudo-nitzschia-australis-frenguelli-bacillariophyceae
#20
Nicolaus G Adams, Piper Schwenke, G Jason Smith, Vera L Trainer
Microsatellites are commonly used markers in population genetics and are increasingly being employed to determine population structure in phytoplankton populations. We have developed seven polymorphic microsatellite markers for the domoic-acid producing diatom Pseudo-nitzschia australis. Using these markers, thirty P. australis isolates were genotyped, 10 isolates were from Monterey Bay, California and 20 were from off the northern coast of Oregon. The number of alleles per locus ranged from two to eight and observed heterozygosities ranged from 0...
January 26, 2017: Protist
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